MERCK LONG TERM DISABILITY PLAN SUMMARY PLAN DESCRIPTION

MERCK LONG TERM DISABILITY PLAN SUMMARY PLAN DESCRIPTION Effective Oct. 13, 2015

This Summary Plan Description (SPD) describes the long-term disability benefits provided under the Merck Medical, Dental, Life Insurance and Long Term Disability Plan as it applies to U.S.-based 1 employees of the wholly owned U.S. subsidiaries of Merck & Co., Inc. (excluding employees of Telerx Marketing, Inc., Comsort, Inc., Vree Health LLC, HMR Weight Management Services Corp. and Merck Global Health Innovation Fund, LLC and each of their subsidiaries) and excluding employees subject to a collective bargaining agreement with the United Steelworkers Union Local 10-00086. A list of the collective bargaining units whose members are eligible to participate in the long-term disability benefits under Merck Medical, Dental, Life Insurance and Long Term Disability Plan as described in this SPD is included as Exhibit A. For Legacy Schering and Legacy Organon (OBS) Employees whose long-term disability benefits commenced prior to Jan. 1, 2011, this SPD does not apply to you. Your long-term disability benefits are based on the plan provision in effect on the date of your disability. Please refer to Exhibit B for more information regarding your LTD coverage. Frequently Used Terms Key words that are frequently used in the SPD are capitalized and defined in the Glossary. The long-term disability benefits described in this SPD provided under the Merck Medical, Dental, Life Insurance and Long Term Disability Plan are referred to in this SPD as the Long Term Disability Plan, the LTD Plan or the Plan. About This SPD This SPD does not apply to any employee or former employee of Merck & Co., Inc. or its subsidiaries or joint ventures other than those specified above. This SPD merely summarizes the benefits and benefit coverage levels provided under the LTD Plan. This SPD reflects the provisions of the LTD Plan in effect as of Oct. 13, 2015. It replaces the SPD effective Oct. 14, 2014, entitled Merck Long Term Disability Plan Summary Plan Description and all summaries of material modifications applicable to it dated before Oct. 13, 2015. Excluded From This SPD The Merck Medical, Dental, Life Insurance and Long Term Disability Plan also provides long-term disability benefits to employees of Merck Sharp & Dohme Corp. who are members of the United Steelworkers Union Local 10-00086 collective bargaining unit. For long-term disability benefits provided to the United Steelworkers Union Local 10-00086 collective bargaining unit, see the Long Term Disability Plan Summary Plan Description for USW 10-00086. To receive a copy of the SPD that describes the benefits provided under the Plan to this group, contact the Merck Benefits Service Center at Fidelity at 800-66-MERCK (800-666-3725). For Legacy Schering and Legacy Organon (OBS) Employees whose long-term disability benefits commenced prior to Jan. 1, 2011, this SPD does not apply to you. Your long-term disability benefits are based on the plan 1 A U.S.-based employee is an employee whose home country is designated in Merck s employee data base as one of the 50 U.S. states or District of Columbia (and includes employees on temporary international assignment outside one of the 50 U.S. states or District of Columbia) and excludes employees whose home country is designated in Merck s employee data base as a U.S. territory (e.g., Puerto Rico, Guam and U.S. Virgin Islands) or a country outside one of the 50 U.S. states or District of Columbia even if the employee is on temporary international assignment in one of the 50 U.S. states, District of Columbia or in a U.S. territory.

provision in effect on the date of your disability. Please refer to Exhibit B for more information regarding your LTD coverage. Right to Amend or Terminate the Plan The Plan Sponsor reserves the right to amend the Merck Medical, Dental, Life Insurance and Long Term Disability Plan, including but not limited to the long-term disability benefits under the LTD Plan, in whole or in part or to completely discontinue the Merck Medical, Dental, Life Insurance and Long Term Disability Plan or the LTD Plan at any time.

TABLE OF CONTENTS Introduction... 1 Your LTD Plan Options... 1 Benefits Contacts and Resources... 1 General Information... 3 LTD Eligibility... 3 Enrolling in an LTD Plan Option... 3 Enrollment... 4 How to Enroll... 4 When Coverage Begins... 5 Paying for LTD Coverage... 5 Making Changes to Your Coverage... 6 When LTD Coverage Ends... 8 How the LTD Plan Works... 9 LTD PLAN Options... 9 About the LTD Plan Options... 9 How the LTD Plan Works... 9 Your LTD Benefit Amount... 10 Applying for Social Security Disability... 14 Medicare Eligibility... 14 When LTD Benefits End... 15 Continuation of Other Merck Benefits... 16 Important Information About The LTD Plan... 17 Administrative Information... 17 Misstatement of Age... 17 Payments in the Event of Incapacity... 17 Recovery Provisions... 17 Your Rights Under USERRA... 17 Your Rights Under ERISA... 18 How to File a Claim... 20 Claims and Appeals... 20 Claims and Appeals for Eligibility to Participate in the LTD Plan... 22

Plan Disclosure Information... 23 Glossary... 27 Exhibit A... 31 Exhibit B... 32

1 INTRODUCTION The Long Term Disability (LTD) Plan offers you several options for coverage. This section provides a brief overview of all the LTD Plan options and resources that are available to you as an Eligible Employee. Your LTD Plan Options The LTD Plan is designed to provide Eligible Employees with a percentage of their Base Pay during certain extended periods of sickness or injury when the Eligible Employees are certified as Disabled, as defined in this SPD, by the Life Insurance Company of North America (a subsidiary of Cigna), the LTD Plan s Claims Administrator referred to as Claims Administrator or Cigna throughout this SPD. The LTD Plan offers the following coverage options: Before-Tax: 60% of Base Pay After-Tax: 60% of Base Pay, or 70% of Base Pay. KEY POINT ENROLLING IN LTD COVERAGE Enrollment in the LTD Plan is through the the service provider for administration of the Company s health and insurance benefits. Eligible Employees can enroll in an LTD Plan option online or by phone. Benefits Contacts and Resources Two vendors administer and help answer questions about the LTD Plan. This chart will help you decide who to contact depending on your needs. When You Want To Contact How Obtain Plan literature and forms View the SPDs Ask a benefits-related question If you re an Eligible Employee: Enroll in your benefits when first hired or during annual enrollment Access information and updates about all of the Company s benefits Merck Benefits Service Center at Fidelity 800-66-MERCK (800-666-3725) TDD: 888-343-0860 Customer Service Representatives are available Monday through Friday (excluding New York Stock Exchange holidays) between 8:30 a.m. and 8:30 p.m. ET. If you re enrolled in any of the LTD Plan options: Ask a specific coverage question Check the status of a claim Cigna 800-238-2125 http://www.mycigna.com Representatives are available Monday through Friday between 8:00 a.m. and 5:00 p.m. ET.

2 The ( Benefits Service Center ) can help you with enrollment and eligibility information and questions. It is administered by Fidelity Investments and available online and by phone. Online: Fidelity NetBenefits at If you have an existing NetBenefits account, use the same username/login information you used previously. By Phone: 800-66-MERCK (800-666-3725) or TDD at 888-343-0860 Customer Service Representatives are available Monday through Friday (excluding New York Stock Exchange holidays) between 8:30 a.m. and 8:30 p.m. ET. For overseas calls dial your country s toll-free AT&T USADirect access number then enter 800-666-3725. In the U.S., call 800-331-1140 to obtain AT&T USADirect access numbers. KEY POINT CONTACTING THE BENEFITS SERVICE CENTER To contact the Benefits Service Center, online or by phone, you will need a password. Your password provides security to ensure that only you can access your benefits information. Keep your password in a confidential place. You can establish your password directly online or by calling the Benefits Service Center. If you have an existing NetBenefits account, use the same username/password information you used previously. If you have forgotten your username or password, you will need to reset it using Having trouble with your username or password? on the login page. When you change your username or password, the change will apply to all your Fidelity accounts and services going forward.

3 GENERAL INFORMATION This section provides Eligible Employees with important information about LTD coverage including eligibility, enrollment, contributions and when you can make changes to your coverage. LTD Eligibility If you are an Eligible Employee, you are eligible for coverage in the LTD Plan as of your date of hire, rehire or transfer. You are not eligible for coverage under the LTD Plan if you are not an Eligible Employee, or if you are an Excluded Employee or Excluded Person. For Dependents You cannot enroll your spouse/domestic partner/ and/or children for LTD coverage. Enrolling in an LTD Plan Option KEY POINT TIME LIMITS AND EVIDENCE OF INSURABILITY MAY APPLY You have 30 days from the later of the date you become eligible to participate in the LTD Plan and the date on the cover letter provided in your benefit enrollment materials from the Benefits Service Center to elect coverage (the Initial Enrollment Period ). If you do not elect coverage within your 30-day Initial Enrollment Period, you will automatically receive the Before-Tax 60% of Base Pay option at no cost to you. See Enrollment for Newly Hired, Rehired or Transferred Employees. If you subsequently elect to purchase additional LTD coverage and increase your coverage amount during annual enrollment, your Company-provided coverage will become After-Tax coverage and you may be subject to Evidence of Insurability (EOI) requirements. See EOI. LTD Plan Options The LTD Plan options for which you are eligible appear online at and depend on your employment status. You may also call the Benefits Service Center at 800-66-MERCK (800-666-3725) to find out which options are available to you. Generally, the Company provides coverage equal to 60% of Base Pay. You can elect whether you want this Company coverage to be provided on a Before-Tax or After-Tax basis. You may also be eligible for additional LTD coverage for a total disability benefit of 70%, which you can elect to purchase with After-Tax dollars. If you elect additional coverage, your Company-provided coverage will also be provided on an After-Tax basis. When you elect the After-Tax option, you will be taxed on the value of the Company-provided coverage, which is called imputed income, and your current federal taxable income is not reduced by the amount of your monthly contributions for additional coverage. However, if you later receive LTD income replacement benefits, under current law the benefits are not subject to federal income taxes. This means the net LTD Benefit received by you will be larger than if you elected the Before-Tax option. With the Before-Tax option, you will not be taxed on the value of the Company-provided coverage. However, if you later receive monthly income from the LTD Plan, that income will be subject to federal income tax and therefore the net LTD Benefit received by you will be smaller than if you elected an After-Tax option. Also if you elect the Before-Tax option, you will be limited to benefits of 60% of Base Pay.

4 Enrollment KEY POINT EOI MAY APPLY When you are first eligible, you have 30 days in which to elect coverage. If you subsequently increase your coverage amount during annual enrollment, you may be subject to EOI requirements. See Evidence of Insurability. Automatic Coverage You are automatically enrolled for coverage in the Before-Tax 60% of Base Pay option at no cost to you as of your date of hire, rehire or transfer. Changing Your LTD Plan Option Within Your 30-Day Initial Enrollment Period You may elect to change your LTD Plan option within your 30-day Initial Enrollment Period through the Benefits Service Center online or by phone to the Company-paid After-Tax 60% of Base Pay option or to the Companypaid and employee-paid After-Tax 70% of Base Pay Option. As long as you enroll for coverage within your 30- day Initial Enrollment Period your coverage will be effective as of your hire, rehire or Transfer Date. See How to Enroll for more detailed instructions. If You Do Not Enroll Within Your 30-Day Initial Enrollment Period If you do not elect to change your LTD Plan option within your 30-day Initial Enrollment Period, you will have LTD coverage in the Before-Tax 60% of Base Pay option for the remainder of the Plan Year. You will not be able to change LTD Plan options until the next annual enrollment period at which time you may be subject to EOI requirements, even if you experience a Life Event that allows you to make a mid-year Permitted Plan Change. See Making Changes to Your Coverage for more information. You should carefully consider whether to default to the Before-Tax option or elect one of the After-Tax options, in order to receive a larger LTD Benefit in the event you become Disabled. How to Enroll You enroll in the LTD Plan through the Benefits Service Center, online or by phone. Online Follow these steps for enrolling in an LTD Plan option: Log on to NetBenefits and click Review Your Checklist at the top of the home page. Under the Starting at Merck section, expand the Set up your health and insurance benefits section and then click Enroll. Before you select your benefits, click Review to update your dependent information. To enroll, change or decline your coverage, click Review next to each benefit offering. Click Save and Submit when you are done. A confirmation screen will display the elections you submitted. Print this page for your records as evidence of your successful enrollment.

5 KEY POINT COMPLETING ENROLLMENT IS YOUR RESPONSIBILITY When you enroll, it is your responsibility to complete all the required steps described above. You should print a copy of your enrollment confirmation statement and keep it with your important papers as evidence of your successful completion of the enrollment process. By Phone Customer Service Representatives can take your benefit elections by phone between 8:30 a.m. and 8:30 p.m. ET, Monday through Friday (excluding New York Stock Exchange holidays). Once you enroll by phone, it s a good idea to confirm your benefit elections online and print your confirmation statement. If you are unable to print your confirmation statement and would like to request a paper copy, you can contact the Benefits Service Center. In the U.S.: Call 800-66-MERCK (800-666-3725). TDD service for the hearing impaired: Call 888-343-0860. For overseas calls: Dial your country s toll-free AT&T Direct access number then enter 800-66-MERCK (800-666-3725). In the U.S., call 800-331-1140 to obtain AT&T Direct access numbers. From anywhere in the world, access numbers are available online at http://www.att.com/traveler or from your local operator. When Coverage Begins Your LTD coverage begins on your date of hire, rehire or transfer. EOI EOI is required if you elect to increase your amount of LTD coverage during annual enrollment. EOI is not required the first time you are eligible to elect LTD coverage. Note: EOI may also be called Statement of Good Health or Proof of Insurability. To provide EOI, you must submit an EOI Form to the Claims Administrator within 60 days of the date of requested change. The Claims Administrator may request additional information, such as records from your health care provider or test results used in evaluating your insurability. A physical exam, at your own expense, may be required. If EOI is required to change your coverage, such change in coverage will not be effective unless the Claims Administrator determines that you have met the EOI requirements. If the Claims Administrator determines that you have met the EOI requirements, the change in coverage is effective on the date the Claims Administrator approves the EOI application. Your payroll deductions will begin the first of the month following the coverage effective date. Paying for LTD Coverage If you are an Eligible Employee, the Company-paid LTD Plan option of Before-Tax 60% Base Pay is automatically provided at no cost to you. If you are an Eligible Employee, you may elect the Company-paid After-Tax 60% of Base Pay option or the Company-paid and employee-paid After-Tax 70% of Base Pay Option. Depending on the option you elect, you may be required to contribute toward the cost of your LTD coverage. Log in to to view your costs and for more information on the different LTD Plan options.

6 Choosing Between Before-Tax and After-Tax Options The difference between how to pay for LTD coverage with Before-Tax or After-Tax dollars is a matter of when you pay taxes and possibly how much you will pay: When you elect the Company-paid After-Tax 60% of Base Pay option, you will pay additional taxes on the value of the Company-provided coverage. You will also be able to purchase additional coverage with you After-Tax dollars and receive a benefit of 70% of Base Pay if you become Disabled. You will not have to pay federal income tax on any future disability benefits you receive under the LTD Plan. When you elect the Company-paid Before-Tax 60% of Base Pay option, you will not have additional taxable compensation now. However, if you become eligible to receive monthly income from the LTD Plan, your benefit payments will be subject to federal income tax. This means you need to decide whether you would rather select an After-Tax option and have a larger LTD Benefit payment, since it will be a federal tax-free payment if you become Disabled, or whether to select the Before-Tax option to receive immediate tax savings, but you will receive a smaller LTD Benefit payment in the event you become Disabled. Imputed Income When you enroll in the 60% After-Tax option, the value of that coverage will be treated as imputed income to you. Imputed income is the amount the IRS requires to be added to your taxable pay to account for the value of the coverage. When you enroll in the 70% After-Tax option, the cost for the additional coverage will be deducted from your pay on a pre-tax basis and then the value of that additional coverage will also be treated as imputed income to you. KEY POINT SEEK TAX ADVICE BEFORE DECIDING HOW TO PAY FOR YOUR COVERAGE You should speak with a tax expert before deciding whether to pay for your coverage on a Before-Tax or After-Tax basis: If you choose the Before-Tax 60% of Base Pay Option, you will not pay taxes on the value of the coverage you elect, but the LTD Benefit you receive should you become Disabled will be subject to federal taxes. If you choose the After-Tax 60% or 70% of Base Pay Options, you will pay taxes now on the value of the coverage you purchase, but the LTD Benefit you receive should you become Disabled will not be subject to federal taxes. Making Changes to Your Coverage Annual Enrollment Each year during annual enrollment, you may elect to make changes to your LTD Plan coverage or keep your current LTD Plan option, subject to its continued availability. Generally, the benefit elections you make will remain in effect for the entire Plan Year (Jan. 1 Dec. 31). Changes made during the annual enrollment period are effective Jan. 1 of the following year, provided you are actively at work on that date. For example, you cannot increase from 60% to 70% coverage while you are absent from work on short-term disability or Workers Compensation. If you elect to increase your coverage and are required to provide EOI, your increased coverage will only be effective if the Claims Administrator determines that you have met the EOI requirements, and it will be effective on a prospective basis, based on the date the EOI determination is made.

7 Each year, you will be notified of the annual enrollment procedures, coverage costs and timeframes for enrolling in or changing your elections for the upcoming Plan Year. Since the Plan Sponsor may make changes to the LTD Plan at any time, it is important to review your annual enrollment materials carefully when you receive them. You may access annual enrollment materials, obtain contact information, review Plan design changes and confirm most benefits online at. If You Take a Leave of Absence Approved Paid Leave of Absence. If you take an approved paid leave of absence, the Companyprovided and any employee-paid additional LTD coverage will continue. In addition, the selected tax treatment of the Company-provided and employee-paid additional coverage, if any, will continue unchanged. You will be taxed on the value of the coverage on the same basis (Before-Tax or After-Tax) as before your leave began. Approved Unpaid Leave of Absence. If you take an approved unpaid leave of absence, Companyprovided LTD coverage will also continue and you will be taxed on the value of the coverage on the same basis (Before-Tax or After-Tax) as before your leave began. You will also be entitled to continue your additional LTD 70% Base Pay coverage. You will be billed for the cost of the additional LTD coverage during your leave by the Benefits Service Center and you will be required to pay the contributions with After-Tax dollars. If you fail to pay premiums to continue coverage in the time and manner specified by the Plan Administrator, your additional LTD 70% base pay coverage will terminate as of the last day of the month for which contributions were timely received and you will then be enrolled in the 60% After-Tax Base Pay coverage option. If your After-Tax 70% of Base Pay option ends due to non-payment of premiums, you will not be entitled to re-enroll in the After-Tax 70% of Base Pay option until the annual enrollment period that occurs after you return to active employment and EOI may be required. You can commence to receive LTD Benefits if you become Disabled while on an approved leave of absence, whether paid or unpaid, provided you are otherwise eligible. You also can commence to receive benefits if you are absent due to a disability that qualifies you to receive disability benefits from your employer. During an unapproved leave of absence, your LTD coverage ends and you cannot commence to receive LTD Benefits. If You Are an Eligible Union Employee Who Goes on Layoff At the time you go on layoff, your LTD coverage ends and you cannot commence to receive LTD Benefits. If you are receiving LTD benefits when you go on layoff, your LTD benefits will not be affected. If You Retire Retirement is treated as any other termination of employment for purposes of the LTD Plan. If you retire, you cannot commence to receive LTD Benefits unless you have satisfied the 26-week Eligibility Period by the last day of the month in which your employment terminates. If you have satisfied the 26-week Eligibility Period by then, your LTD Benefit can continue while you remain Disabled or, if earlier, the date described under When LTD Coverage Ends. If you are Disabled and receiving an LTD Benefit, your LTD Benefit is offset by your pension payments, if any, as described in Other Income Sources/Offset. If You Die If you are receiving or you are eligible to begin receiving LTD Benefits and then you die, LTD Benefits end with the payment made in the month of your death. If you die before you are eligible to begin receiving LTD Benefits, no LTD Benefits are payable.

8 When LTD Coverage Ends You cannot begin to receive LTD Benefits after the earliest of: The last day of the month in which your employment terminates (unless as of that date you are eligible to receive LTD Benefits) The date you are no longer eligible to participate The date you begin an unapproved leave of absence and continuing for the entire period of your unapproved absence The date you die The day as of which you agree to waive Plan participation on a form acceptable to the Company, or The date the LTD Plan is terminated by the Plan Sponsor. If you are Totally Disabled and benefits have already begun, see When LTD Benefits End for when your LTD Benefits end.

9 HOW THE LTD PLAN WORKS LTD PLAN OPTIONS The LTD Plan replaces a percentage of your Base Pay if you become Totally Disabled and are unable to work. When determining how much long-term disability (LTD) coverage you need, keep in mind how much protection you would need if you could no longer work to support yourself and your family. This benefit is administered by Cigna, also known as the Claims Administrator, which has the discretion to make the factual and other determinations necessary to determine if you are Totally Disabled. About the LTD Plan Options Generally, you may elect one of the following LTD Plan options, on either a Before-Tax or After-Tax basis. Company-provided coverage that provides benefits of 60% of Base Pay. This coverage can be Before- Tax or After-Tax based on the Eligible Employee s election. Employee-paid After-Tax coverage that brings the total benefits to 70% of Base Pay. If an employee elects additional coverage, then both Company-provided and employee-paid coverage will be After-Tax. However, eligibility to elect a particular option depends on your employment status. For more information on Before-Tax or After-Tax options, see Paying for LTD Coverage. KEY POINT EMPLOYEES ON LTD BEFORE JAN. 1, 2011 If you are an LTD Employee whose disability began prior to Jan. 1. 2011, your LTD Benefits and options will continue according to your prior election even if you are covered under an LTD Plan option that is not listed above. Key Features In general, under the LTD Plan options: You continue to receive an income if you become Totally Disabled and are unable to work for an extended time. You are eligible to receive LTD Benefits after you have been Totally Disabled for the consecutive 26-week Eligibility Period. The amount of your LTD Benefit varies depending on the LTD Plan option you have elected. The LTD Benefit you receive from the Plan will be reduced by any benefits you and your family receive from Social Security as well as other sources of income described in the Other Income Sources/Offset section. If you elect Before-Tax coverage and are not taxed on the value of the Company-provided coverage, your LTD Benefit will be taxable when paid. If you elect After-Tax coverage and are taxed on the value of Company-provided and employee-paid coverage, your LTD Benefit will not be subject to federal taxes when it is paid. How the LTD Plan Works You are eligible to receive LTD Benefits after you have been continuously Totally Disabled for 26 consecutive weeks (182 days). This is known as the Eligibility Period. If you return to work for less than 30 consecutive

10 calendar days during the Eligibility Period, you are not required to satisfy another Eligibility Period. Note: the Eligibility Period is completely independent of any short-term disability payments you receive. To be eligible to receive LTD Benefits, your employment must continue through the first day of the month in which your Eligibility Period ends. For example, if you become Totally Disabled on March 15 and do not return to work, your Eligibility Period would end 26 weeks later on Sept. 13. If your employment ends for any reason (including retirement) before Sept. 1, you would not be eligible for LTD Benefits. You also cannot have changed status (for example, become an employee of a subsidiary that does not participate in the LTD Plan such as Telerx Marketing, Inc., Comsort, Inc., Vree Health LLC, HMR Weight Management Services Corp. and Merck Global Health Innovation Fund, LLC and each of their subsidiaries) before the first day of the month in which your Eligibility Period ends. KEY POINT THE GLOSSARY PROVIDES DEFINITION FOR IMPORTANT BENEFIT TERMS Important benefit terms, such as Totally Disabled, are defined in the Glossary. When LTD Benefits Are Paid If you are approved to receive LTD Benefits, benefits will begin to accrue on the date following the day you complete your benefit Eligibility Period. Payments of the monthly benefit will start on the date one month after completion of the Eligibility Period. Subsequent payments will be made each month thereafter. Payment is based on the number of days you are Totally Disabled during each one month period. After payments begin, proof of your continued disability may be required from time to time. Exclusions LTD Benefits will not be paid for disabilities caused by or resulting from: Active participation in war or an act of war Intentionally self-inflicted injuries, or Commission of or participation in a felony. Your LTD Benefit Amount The LTD Plan pays a benefit based on the LTD Plan option you elect and your annual Base Pay on the first day of your disability. If you are a Regular Part-Time Employee, your Base Pay reflects your scheduled hours as of your first date of disability. For example, if the annual pay for the position is $100,000 for a 40-hour work week, and your regularly scheduled hours are 24 hours per week, your Base Pay is $60,000. Your gross LTD Benefit (before offsets) is rounded to the nearest dollar. Offsets Your LTD payment is reduced by Other Income Benefits, which includes the amount of income you receive from other sources, such as Social Security, vacation payout, severance pay, Workers Compensation and overpayments, as described in the Other Income Sources/Offset section (see Recovery Provisions). Minimum Benefit The LTD Plan generally provides a minimum benefit of $100 per month, unless that would push your LTD Benefit beyond the maximum benefit described below. Your LTD Benefit is coordinated with Social Security and the other sources of income, so that your Total Disability income from all sources equals your chosen percentage of Base Pay.

11 Maximum Benefit Under no circumstances will the Plan provide any benefit that exceeds 85% of your pre-disability Base Pay, including income from other sources. See Other Income Sources/Offset. Other Income Sources/Offset Your LTD Benefits are reduced or offset by certain Other Income Benefits, which are your other sources of income, as follows: Social Security benefits (both primary [paid to you] and family disability [paid to your spouse and/or child] and retirement benefits) that you and your eligible dependents are entitled to receive when you become eligible for LTD Benefits. If you acquire a new spouse or dependent after the date you become eligible for LTD benefits, any additional Social Security benefit for that new spouse or dependent will be an offset. If you do not apply for Social Security disability benefits, your payments from the LTD Plan may be offset by an estimated Social Security amount. It is important that you apply for Social Security benefits. If you receive a retroactive award for Social Security which results in an overpayment, your LTD Benefit may be reduced to repay the overpayment, or the Claims Administrator may request a lump sum payment from you to repay the overpayment. The amount of offset for Social Security benefits shall be computed at the time you qualify for LTD Benefits. Subsequent increases in Social Security benefits due to Cost Of Living Adjustments are not be used to reduce LTD Benefits Any temporary Workers Compensation benefits Total and permanent disability benefits received under the Group Life Insurance Plan (lump-sum payments are pro-rated over a five-year period) Any periodic payment paid by federal, state or local government agencies (excluding pension income resulting from employment by a government agency) The Company pension benefits you have elected to receive (the monthly actuarial equivalent of the Life Income for You Alone amount is used in the event of a lump-sum payment). Merck will advise the Claims Administrator of employees electing to commence their pension benefit in order for the Claims Administrator to calculate the pension benefit offset, if any Any disability benefits paid under any other Company-sponsored plan Any other compensation paid by the Company while you are receiving LTD Benefits, such as holiday and vacation pay, regardless of when the vacation time was earned. Note: Any holiday and vacation payout is considered earnings in the month received. Therefore, if your holiday and vacation payout in a given month exceeds 85% of your pre-disability Base Pay (the Plan s maximum benefit), then no LTD Benefit is paid for that month. If your holiday and vacation payout is less than 85% of your pre-disability Base Pay for the month, you will continue to receive your LTD Benefit offset by your holiday and vacation payout for that month and any Other Income Benefits as described in this section. Any severance pay you receive under the Merck separation plan. Your severance payments will offset your LTD payment for the number of weeks of severance pay you are entitled to receive under the separation plan. Merck will advise the Claims Administrator of the amount of any severance pay paid to you Any disability income benefit provided to you under any law

12 60% of compensation you receive for any Rehabilitative Employment (as described in the Rehabilitative Employment section) from the Company or any other employer, and The full amount you actually received from the Company or any of its benefit plans that you were not entitled to receive, even if you received the amount when you were not yet entitled to LTD Benefits. Your LTD Benefits are not offset by the following sources of income: Social Security disability benefits payable to a participant s disabled dependent on account of the dependent s own disability (applicable to LTD Benefits payable after Jan. 1, 1999, only) Permanent Workers Compensation paid in either a single sum or installments U.S. Military service-connected disability payments Travel Accident Insurance Plan benefits Any Living Benefits you receive from the Life Insurance Plan if you have been diagnosed with a terminal illness Any cost-of-living adjustments to Social Security Disability Income ( SSDI ) benefits Income from Company equity grants such as proceeds from the exercise of Merck stock options or income from restricted stock units or performance share units, and Performance awards and bonuses. An Example of How to Calculate the LTD Benefit Amount Assumptions Base pay at the time of disability: $48,000 annually ($4,000 a month) Social Security disability benefit: $1,300 a month You were covered under the 60% Base Pay option at the time of your disability Your target disability income replacement (60% X $4,000) $2,400 Less your Social Security monthly benefit 1,300 Your monthly benefit from the LTD Plan $1,100 Your Total Disability monthly income from Social Security and the LTD Plan $2,400 In the preceding example, you are entitled to $2,400 a month ($1,100 from the LTD Plan and $1,300 from Social Security). If you paid for your LTD Benefit with Before-Tax dollars, the supplemental rate for federal income tax (currently 25%) is automatically withheld from your LTD Benefit unless you have completed a W-4 form. Some states also require that state tax be withheld.

13 Another Example of How to Calculate the LTD Benefit Amount Assumptions Base pay at the time of disability:$48,000 annually ($4,000 a month) Social Security primary disability benefit: $1,300 a month Social Security family disability benefit: $1,050 a month You were covered under the 60% Base Pay option at the time of your disability Your target disability income replacement (60% X $4,000) Less your primary and family Social Security monthly benefit $2,400 2,350 Your monthly benefit from the LTD Plan ($100 monthly minimum benefit applies) $100 Your Total Disability monthly income from Social Security and the LTD Plan 1 $2,450 $50 If You Recover If, after you satisfy the 26-week Eligibility Period, you recover from your Total Disability and return to active employment, a second disability is considered a new disability and LTD Benefits are payable only after you satisfy a new 26-week Eligibility Period. However, if the second disability is related to the same illness or injury as the first disability and you have returned to active employment for less than 90 days, this is considered one period of disability. Your disability benefit will begin immediately and you will not have to satisfy a new 26-week Eligibility Period. Rehabilitative Employment You may work in Rehabilitative Employment in any occupation approved by the Claims Administrator. The LTD Benefit you receive will equal your target LTD Benefit less 60% of your gross rehabilitative earnings. The initial period of approved Rehabilitative Employment will be three months and may be renewed for up to a total of 24 months. The LTD Plan may cover the cost of an item or service that is not normally authorized under the other terms and provisions of the Plan if the item or service enables you to engage in Rehabilitative Employment. An item or service may be covered by the Plan only if the Claims Administrator considers the expense to be costeffective. Your Physician and a qualified Physician consulted by the Claims Administrator must determine that the item or service is appropriate given your underlying condition/disability. If you discontinue Rehabilitative Employment, the Claims Administrator reserves the right to recoup any expenses initially paid under this provision. Note: If you engage in any occupation or perform any work for compensation or profit, your LTD benefit will cease unless you are engaged in Rehabilitative Employment. 1 Note: this amount is still less than 85% of your $4,000 monthly salary; otherwise the minimum benefit would be less than $100.

Applying for Social Security Disability Your LTD Benefit is coordinated with Social Security and other sources of income so that your Total Disability income from all sources equals your chosen percentage of Base Pay. (For more information, see Other Income Sources/Offset. ) Therefore, it is important that you apply for Social Security Disability Income ( SSDI ) benefits, if appropriate. If you are denied SSDI benefits, the Claims Administrator will assist you with the appeal process. Applying for Social Security disability benefits can be of great value to you. In addition to your monthly payments, there are other important financial advantages. The Claims Administrator will refer you to Advantage 2000, an expert SSDI representation vendor, to help you apply for SSDI benefits, at no cost to you. If you do not use the assistance offered by Advantage 2000 and do not apply for SSDI benefits, the Claims Administrator will reduce your LTD Benefit by the amount it estimates you are eligible to receive. Protecting Your Social Security Retirement Benefits Your Social Security retirement benefit is determined by averaging your earnings over your working career. If you do not collect SSDI benefits, no earnings will be recorded for the period you are collecting LTD Benefits. This zero earnings may lower your overall average earnings and therefore, lower your Social Security retirement benefits. If you apply for and start receiving SSDI benefits, your disability period is not included in determining your career average earnings. This means that the amount of monthly benefit that you will receive from Social Security at normal retirement age will be greater if you apply for immediate SSDI benefits than if you wait until normal retirement age. Cost of Living Increases SSDI benefits are periodically increased due to cost of living adjustments. These adjustments are not applied as additional offsets to your LTD Benefit. This means that your combined monthly disability income will increase with any cost of living increase from Social Security. Vocational Rehabilitation Services While accepting these services, SSDI benefits may continue in full for several months following return to work due to partial disability. Tax Advantages SSDI benefits may be non-taxable depending upon your total income for the year. Medicare Eligibility Under current law, you become eligible for Medicare after you have received Social Security Disability Income (SSDI) benefits for two years. However, you must apply for Medicare in order to be covered. The Company may, but is not obligated to, directly or indirectly provide services to you to assess your eligibility for Medicare and to assist you with the Medicare filing process. Note: The Company-sponsored medical plans coordinate with Medicare whether or not you enroll. This means that although you continue to remain employed by Merck while you are receiving LTD Benefits, you are not actively at work and therefore not considered an active employee. Instead while you are receiving LTD Benefits, you are an inactive employee on a leave of absence. As a result, according to the Center for Medicare and Medicaid Services (CMS) and the Merck Medical Plan, Medicare is the primary payer of your medical coverage, and you must maintain Medicare Part A and B coverage to receive maximum coverage. If you are receiving LTD Benefits and do not apply for Medicare when first eligible, you will see a significant gap in your medical coverage and you may be responsible for a late enrollment contribution penalty when you later enroll in Medicare Part B. You do not need to enroll in Medicare Part D. 14

15 When LTD Benefits End If you become entitled to benefits on or before age 60, benefits are payable until the earliest of the following dates: You are no longer Totally Disabled You reach age 65, or You die. If you become entitled to benefits after age 60, benefits are payable until the earliest of the date: You are no longer Totally Disabled You receive benefits for five years, or You die. Proof of your continued disability may be required from time to time. Benefits may cease (even if you might be Disabled) if you: Do not provide the required medical or financial proof Do not sign the required forms Refuse to undergo a medical exam on request Refuse to follow a reasonable course of treatment prescribed by your health care provider or a health care professional appointed by the Claims Administrator Do not receive regular care and attendance from an appropriate legally-qualified attending Physician Engage in any occupation or perform any work for compensation or profit, for which you have not notified the Claims Administrator, other than Rehabilitative Employment, or Are determined to be ready to return to work and refuse to do so. Benefits will not be paid if you have executed a waiver of Plan participation on a form acceptable to the Company. Your LTD Benefits also end: The date you are released to return to full duty The date you are released to return to work with restrictions and have been receiving LTD Benefits for two years or more, or Whether or not you have restrictions and the Claims Administrator s Transferability Skills Analysis shows that you are capable of performing a different occupation. When your LTD Benefits end, you will no longer be eligible to remain on an LTD leave of absence. If your LTD Benefits end for any reason (other than retirement or death), the Company will automatically place you on an unpaid Administrative Leave of Absence for up to 60 days in order to allow you time to secure a position with the Company. If you are unable to secure a position within the 60 day period, your employment will generally be terminated. You will not be eligible for severance benefits and your termination will not be considered a separation for other purposes, such as your stock options, if any. If, however, you are at least age 55 with 10 years of service at the date your employment ends, you will be considered to have retired from the Company. Your eligibility for early retirement subsidies from the Company s pension plan or eligibility for a Company subsidy for retiree medical coverage is determined by the respective plan provisions. Refer to the SPD of the respective plan for details.

Continuation of Other Merck Benefits While you are an LTD Employee, you are placed on an unpaid LTD leave of absence and are eligible to continue to participate in certain health, insurance, retirement and savings plan benefits. See each respective benefit plan SPD for details about your continued eligibility and how you may continue those coverages and pay any required contributions. The Company reserves the right to modify these eligibility rules at any time. SPDs are available online at or by request through a Benefits Service Center representative at 800-66-MERCK (800-666-3725). The following benefits will cease when you begin receiving LTD Benefits: Accidental Death and Dismemberment (AD&D) Insurance Dependent Care Flexible Savings Account (FSA) Business Travel Accident Insurance Legal Plan, and Savings Plan Employee Contributions and Company Match. Please consult the SPDs for all your Merck benefits for details about how your disability affects those plans. 16

17 IMPORTANT INFORMATION ABOUT THE LTD PLAN ADMINISTRATIVE INFORMATION This section contains information on the administration and funding for the LTD Plan, as well as your rights as an LTD Plan participant. While you may not need this information for day-to-day participation in the LTD Plan, you should read through this section. It is important for you to understand your rights, the procedures you need to follow and the appropriate contacts you may need in certain situations. Misstatement of Age In the event you misstate your age on Company records, your entitlement to LTD Benefits will be based on your correct age. If the LTD Plan has overpaid your benefits, the Claims Administrator has the right to recover overpayments. If the misstatement of age results in LTD underpayments, the Plan will pay you the amount of any underpayment. Payments in the Event of Incapacity If you are entitled to benefits under the LTD Plan but are incapable of properly accepting and receiving such payments, the Claims Administrator will pay benefits to your legally appointed guardian or committee. If you have not appointed a guardian or committee, the Claims Administrator has the discretion to pay benefits to an individual responsible for you. Payment of benefits under one of these arrangements will completely discharge the Plan of all liabilities. Recovery Provisions Whenever payments have been made by the LTD Plan in excess of the maximum amount of payment authorized by the terms of the LTD Plan, or when a Plan participant has refused to reimburse the Plan the amount of any overpayments, we have the right to recover these excess payments or withhold payment of future benefits to offset such excess payments, and you have the obligation to refund to the LTD Plan any such amount. Our rights and your obligations in this regard are also set forth in the reimbursement agreement you are required to sign when you become eligible for benefits under this Plan. This agreement: (i) confirms that you will repay all overpayments; and (ii) authorizes the Claims Administrator to obtain information relating to other income benefits. An overpayment occurs when it is determined that the total amount paid on your claim is more than the total of the benefits due under this Plan. This includes any overpayments resulting from: Retroactive awards received from sources shown in the list of other income sources Fraud, or Any error made in processing your claim. The LTD Plan or its designees may withhold or offset future benefit payments, sue to recover such overpayment, or use any other lawful remedy to recoup any such overpayment. Your Rights Under USERRA The LTD Plan is not subject to the continuation coverage requirements of the Uniformed Services Employment and Reemployment Rights Act of 1994 ( USERRA ). You do not need to take any action to continue coverage under the LTD Plan as described below when you begin your military leave. If you are currently enrolled in the employee-paid After-Tax 70% Base Pay option, you may change this coverage and elect enrollment in the Company-paid After-Tax 60% Base Pay option. However, if you want to

18 make this change to your LTD coverage when you begin your military leave, you must contact the Benefits Service Center within 30 days after your leave begins. If you do not contact the Benefits Service Center within that 30-day period, your coverage under the LTD Plan will continue as described below. Note: If you make an election at the beginning of your military leave to change your LTD benefit from the employee-paid After-Tax 70% base pay option to the Company-paid After-Tax 60% option, you will remain in that option for the duration of your military leave and you will not be able to re-enroll in the 70% Base Pay option until the next annual enrollment period following your return to active employee status subject to the Plan s rules, including any EOI. If you are eligible to continue to receive Base Pay from the Employer during your military leave, coverage will continue in accordance with the LTD Plan s terms and conditions applicable to an employee on a paid leave of absence. Your employee contribution will continue to be deducted from your pay; to the extent your pay is insufficient to pay the required contributions, unpaid contributions will be accumulated and be payable by you when you return to active employee status. If you are not eligible to continue to receive Base Pay from the Employer during your military leave, your coverage will continue while you are an employee of an Employer in accordance with the LTD Plan s terms and conditions applicable to an employee on an unpaid leave of absence. If you had Before-Tax or After- Tax 60% Base Pay coverage in effect on the day immediately prior to the commencement of your military leave, that coverage will continue while you are an employee of an Employer on military leave without cost to you. If you had After-Tax 70% Base Pay coverage in effect on the day immediately prior to the commencement of your military leave, and did not make a change as described above, that coverage will continue while you are an employee of an Employer on military leave provided you timely pay the required employee After-Tax contribution. You will receive a monthly invoice directly from the Benefit Service Center showing the amount of your employee contribution at the active employee rate required to continue your coverage. If you do not pay the required monthly employee contribution in the time and manner specified on the invoice, your After-Tax 70% Base Pay coverage will terminate as of the last day of the month for which employee contributions have been timely received and will not be reinstated while you are on military leave. For the duration of your military leave, you will then be enrolled into the Company-paid After-Tax 60% Base Pay coverage option. When you return to active employee status, during the next annual enrollment period following your return, you may be eligible to re-enroll for coverage at 70% subject to the Plan s rules, including EOI. Note: While you are on a military leave, you may only make a change to your LTD Plan coverage during the annual enrollment period, however, you cannot reinstate any employee-paid LTD Plan coverage until the next Annual Enrollment period following your return to active employee status. During the next annual enrollment period following your return to active employee status, you may be eligible to change your LTD Plan coverage or re-enroll for Employee- paid coverage subject to the Plan s rules, including EOI. Your Rights Under ERISA As a participant in the LTD Plan, you are entitled to certain rights and protections under the Employee Retirement Income Security Act of 1974 ( ERISA ). ERISA provides that all Plan participants will be entitled to the following: Receive Information About Your Plan and Benefits Examine, without charge, at the Plan Administrator s office and at other specified locations, such as worksites and union halls, all documents governing the LTD Plan, including insurance contracts and collective bargaining agreements, and a copy of the latest annual report (Form 5500 Series) filed by the Plan with the U.S. Department of Labor and available at the Public Disclosure Room of the Pension and Welfare Benefit Administration Office.

19 Obtain, upon written request to the Plan Administrator, copies of documents governing the operation of the Plan, including insurance contracts and collective bargaining agreements, and copies of the latest annual report (Form 5500 Series) and updated SPD. The administrator may charge a reasonable fee for the copies. Receive a summary of the Plan s annual financial report. The Plan Administrator is required by law to furnish each participant with a copy of this summary annual report. Prudent Actions by Plan Fiduciaries In addition to creating rights for Plan participants, ERISA imposes duties upon the people who are responsible for the operation of the employee benefit plan. The people who operate your Plan, called fiduciaries of the Plan, have a duty to do so prudently and in the interest of you and other Plan participants and beneficiaries. No one, including your employer, your union or any other person, may fire you or otherwise discriminate against you in any way to prevent you from obtaining a welfare benefit or exercising your rights under ERISA. Enforcing Your Rights If your claim for a welfare benefit is denied or ignored, in whole or in part, you have a right to know why this was done, to obtain copies of documents relating to the decision without charge and to appeal any denial, all within certain time schedules. For more information, see Claims and Appeals. Under ERISA, there are steps you can take to enforce the above rights. For instance, if you request a copy of Plan documents or the latest annual report from the Plan and do not receive them within 30 days, you may file suit in a federal court. In such a case, the court may require the Plan Administrator to provide the materials and pay you up to $110 a day until you receive the materials, unless the materials were not sent because of reasons beyond the control of the Plan Administrator. If you have a claim for benefits which is denied or ignored, in whole or in part, you may file suit in a federal court. If it should happen that the Plan fiduciaries misuse the Plan s money, or if you are discriminated against for asserting your rights, you may seek assistance from the U.S. Department of Labor, or you may file suit in a federal court. The court will decide who should pay court costs and legal fees. If you are successful, the court may order the person you have sued to pay these costs and fees. If you lose, the court may order you to pay these costs and fees, for example, if it finds your claim is frivolous. Assistance with Your Questions If you have any questions about the LTD Plan, you should contact the Plan Administrator. If you have any questions about this statement or about your rights under ERISA, or if you need assistance in obtaining documents from the Plan Administrator, you should contact the nearest office of the Pension and Welfare Benefits Administration, U.S. Department of Labor, listed in your telephone directory or the Division of Technical Assistance of the Employee Benefits Security Administration at: Division of Technical Assistance/Employee Benefits Security Administration U.S. Department of Labor 200 Constitution Avenue, N.W. Washington, DC 20210 You may also obtain certain publications about your rights and responsibilities under ERISA by calling the publications hotline of the Employee Benefits Security Administration at 866-444-3272 or accessing their website at http://www.dol.gov/ebsa.

How to File a Claim You must file a claim form with the Claims Administrator in order to receive benefits from the LTD Plan. Claim forms are available from the Claims Administrator. Instructions for filing a claim are included on the form. You should make a copy of the claim form for your records and send the original to: Claims Administrator for the Long Term Disability Plan Cigna Group Insurance Long-Term Disability P.O. Box 22308 Pittsburgh, PA 15222-0308 Phone: 800-238-2125 You must complete your initial application for LTD Benefits no later than 180 days after the day you complete your benefit Eligibility Period unless you can prove that you completed the application as soon as was reasonably possible. In all events, you must complete the application by the first anniversary of the day you complete your benefit Eligibility Period. If you fail to do so, you are ineligible for LTD Benefits even if you might otherwise satisfy the definition of Totally Disabled. The Claims Administrator may determine that special circumstances exist to permit waiver of this provision, such as where the person making the claim lacks legal capacity. To Whom Paid LTD Benefits are generally payable to the Eligible Employee. If the Eligible Employee lacks legal capacity or dies while any LTD Benefit remains payable, in its discretion the Claims Administrator may provide the LTD Benefit to another person, such as the Eligible Employee s legal guardian or executor of the Eligible Employee s estate. Claims and Appeals If you or your authorized representative feels that the Claims Administrator has made an error concerning your benefits, you or your authorized representative have the right to request reconsideration under the Plan in accordance with the following procedure. Note: all requests for reconsideration will be submitted in writing to the Claims Administrator. See Benefits Contacts and Resources for Written Appeals for address information. Initial Claim The Claims Administrator is responsible for evaluating all benefit claims. The Claims Administrator will review your claim in accordance with its standard claims procedures, as required by ERISA. The Claims Administrator has the right to secure independent disability advice and to require other evidence as it deems necessary in order to decide the status of your claim. The Claims Administrator will make every effort to make a determination on your claim within 45 days of receipt of your claim. If, for reasons beyond control of the Plan, the Claims Administrator is not able to make a decision on your claim within such 45-day period, the Plan Administrator may extend the period for making the decision for up to 30 additional days. In that event, the Claims Administrator will provide you with a written notice of the extension that describes the specific reasons beyond the control of the Plan for the delay prior to the end of the initial 45-day period. The notice will identify any additional information or documents needed to resolve your claim and the date by which a decision is expected. You will be allowed at least 45 days to provide any information needed from you. The time it takes for you to provide this additional information will not count toward the extension period time limit. A second 30-day extension may occur if your claim still cannot be resolved for reasons beyond the control of the Plan. The Claims Administrator will provide you with a written notice of the extension that describes the specific reasons for the delay prior to the end of the first 30-day extension. The notice will identify any 20

21 additional information or documents needed to resolve your claim and the date by which a decision is expected. You will be allowed at least 45 days to provide any information needed from you. The time it takes for you to provide this additional information will not count toward the extension period time limit. The maximum time to make a decision on your claim, not including the time it takes for you to provide additional information or documents that the Claims Administrator has requested from you, will be 105 days. If Your Claim Is Denied If the Claims Administrator does not fully agree with your claim, you will receive an adverse benefit determination, which is a denial, reduction or termination of a benefit. You will receive notice of a denial, which will include: The specific reasons for the denial The specific Plan provisions on which the denial is based A description of any additional information needed to reconsider the claim and the reason this information is needed A description of the Plan s review procedures and the time limits applicable to such procedures A statement of your right to bring a civil action under ERISA following a denial on review Any internal rules, guidelines, protocols or similar criteria that were used as a basis for the denial, either the specific rule, guideline, protocols or other similar criteria or a statement that a copy of such information will be made available free of charge upon request, and For a denial based on medical necessity, experimental treatment or other similar exclusions or limits, an explanation of the scientific or clinical judgment used in the decision or a statement that an explanation will be provided free of charge upon request. Appealing a Claim If your claim for benefits is denied, in whole or in part, you or your authorized representative may appeal the denial within 180 days of the receipt of the written or electronic notice of denial. If you choose to appeal your claim, your appeal should be in writing and should explain why you believe the claim should be paid. See Benefits Contacts and Resources for Written Appeals section for more information. Upon your request, you will have access to, and the right to obtain copies of, all documents, records and information relevant to your claim free of charge. You may submit with your appeal any written comments, documents, records and any other information relating to your claim, even if you didn t include that information with your original claim. Reviewers must take all the information into account, even if it was not submitted or considered in the initial decision. The review will not afford any deference to the initial claim determination. A qualified individual who was not involved in the previous claim determination (and is not that person s subordinate) will decide your appeal. If your appeal involves a medical judgment, the review will be done in consultation with a health care professional who has appropriate training and experience in the relevant field of medicine involved in the medical judgment, who was not consulted in connection with the previous adverse claim determination and who is not that person s subordinate. After receiving your appeal, the Claims Administrator will provide notice of its decision within a reasonable period of time, but not later than 45 days after receipt of your appeal, unless special circumstances, such as the need to hold a hearing, require an extension of time for processing the claim.

22 If an extension of time is required, the initial 45-day period may be extended once by up to 45 days, provided the Claims Administrator or its delegate notifies you within the initial period of the special circumstances requiring the extension and the date by which the Plan expects to render the determination review. You will receive written or electronic notification of the determination of your appeal. If the claim on appeal is denied in whole or in part, the notice will include: The specific reason or reasons for the adverse determination References to the specific Plan provisions on which the determination was based A statement that you are entitled to receive upon request and free of charge reasonable access to, and copies of, all records, documents and other information relevant to your benefit claim If the denial is based on medical necessity, experimental treatment or other similar exclusion or limit, an explanation of the scientific or clinical judgment used in making the decision A statement that you have the right to obtain upon request and free of charge, a copy of internal rules or guidelines relied upon in making this determination, and if the determination is based on medical necessity or experimental treatment or similar exclusion or limit, an explanation of the scientific or clinical judgment for the determination, applying the terms of the Plan to your medical circumstances, and A statement of your right to bring a civil action under ERISA following an adverse benefit determination on review. If you do not agree with the final determination on review, you have the right to bring a civil action, if applicable. Exhaustion of Process You must exhaust the appeal procedure before you initiate any litigation, arbitration or administrative proceeding regarding the denial of your appeal or any matter within the scope of the appeals procedure. Claims and Appeals for Eligibility to Participate in the LTD Plan If you or your authorized representative feel that an error has been made concerning your eligibility to participate in the Plan (e.g., your eligibility to elect a particular coverage option), you or your authorized representative may request reconsideration under the Plan. All requests for reconsideration will be submitted in writing to the Plan Administrator at the following address: Merck Sharp & Dohme Corp. Attn: Plan Administrator (GSA-HTR) c/o P.O. Box 770003 Cincinnati, OH 45277-0065 Express mail address: Merck Sharp & Dohme Corp. Attn: Plan Administrator (GSA-HTR) c/o Mail Zone KC1F-L 100 Crosby Parkway Covington, KY 41015 The Plan or Claims Administrator will review your claim and respond to you with a determination. Its decision is final and binding.

23 Benefits Contacts and Resources for Written Appeals The following chart lists the appeals address for each of the available LTD Plan coverage options and/or benefit features of the Plan. If a Claim Is Denied Benefit Appeals For all LTD Plan options Eligibility Appeals For all LTD Plan options Send Your Written Appeal to the Claims Administrator at this Address: Claims Administrator and fiduciary for the LTD Plan: Cigna Group Insurance Long-Term Disability P.O. Box 22308 Pittsburgh, PA 15222-0308 Plan Administrator for the LTD Plan: Merck Sharp & Dohme Corp. Attn: Plan Administrator (GSA-HTR) c/o P.O. Box 770003 Cincinnati, OH 45277-0065 Plan Disclosure Information Employer/Sponsor Express mail address: Merck Sharp & Dohme Corp. Attn: Plan Administrator (GSA-HTR) c/o Mail Zone KC1F-L 100 Crosby Parkway Covington, KY 41015 Merck Sharp & Dohme Corp. sponsors the Merck Medical, Dental, Life Insurance and Long Term Disability Plan. The employer identification number assigned to Merck Sharp & Dohme by the IRS is #22-1261880. The address and phone number for Merck Sharp & Dohme Corp. is: Merck Sharp & Dohme Corp. Attn: Plan Administrator (GSA-HTR) c/o P.O. Box 770003 Cincinnati, OH 45277-0065 Express mail address: Merck Sharp & Dohme Corp. Attn: Plan Administrator (GSA-HTR) c/o Mail Zone KC1F-L 100 Crosby Parkway Covington, KY 41015 Telephone: 866-MERCK-HD (866-637-2543) For U.S. employees calling from outside of the United States: +1-908-423-HELP (+1-908-423-4357)

24 Plan Administrator/Claims Administrator The Plan Administrator for the Plan is Merck Sharp & Dohme Corp. The Claims Administrator determines eligibility in accordance with the official Plan documents. Cigna is the Claims Administrator for the LTD Plan. The Plan Administrator has the exclusive discretion to construe and interpret the terms of the LTD Plan as follows: To adopt such rules for the administration of the Plan as it considers desirable To make factual determinations, interpret and construe the Plan, correct defects, supply omissions and reconcile inconsistencies to the extent necessary to effectuate the Plan, resolve all questions arising in the administration, interpretation and application of the Plan, and such action will be conclusive upon the Company, the Plan, participants, employees, their dependents and beneficiaries To decide all questions of eligibility and participation To prescribe procedures and election forms to be followed by participants to make elections to this Plan To accept, modify or reject elections under the Plan To authorize disbursements on behalf of the Plan To prepare and distribute to participants information explaining the Plan and the benefits available hereunder in such a manner as the Plan Administrator deems appropriate To settle any lawsuit against the Plan or Plan Administrator, and To request and receive from all participants such information as the Plan Administrator will from time to time determine to be necessary for the proper administration of the Plan. The Plan Administrator has reserved the right to delegate all or any portion of its authority described above to a representative. The Plan Administrator has delegated all of its authority described above with respect to authorizing disbursements for benefits on behalf of the LTD Plan and adjudicating claims and appeals for benefits (and handling any resulting lawsuits) under the LTD Plan to the Claims Administrator. That means that the Claims Administrator has the sole authority to determine such matters under the Plan and the Plan Administrator will not and cannot substitute its judgment for that of the Claims Administrator on such matters. It also means the Claims Administrator has all of the discretion described above to the extent it relates to the Claims Administrator s duties under the LTD Plan, for example regarding eligibility for benefits, according to the broad discretion set forth above. The amounts paid to the Claims Administrator by the Company and the Plan are designed to, and do, ensure that the Claims Administrator is not subject to influence by Plan Sponsor or its subsidiaries, including but not limited to financial influence, as the Claims Administrator acts as a fiduciary for the Plan and the Plan participants. The Plan Sponsor designed this structure to ensure that any court reviewing determinations made by the Claims Administrator will defer to the Claims Administrator s decisions unless the court finds that the determination was both arbitrary and capricious, a highly deferential standard. Contact the Plan Administrator if you have any questions about the LTD Plan other than routine questions or questions about the filing or status of claims under the Plan. For routine questions, call the Benefits Service Center at 800-66-MERCK (800-666-3725). For questions about the filing status of claims, contact the Claims Administrator at 800-238-2125 or write to the address listed in Benefits Contacts and Resources for Written Appeals.

25 Agent for Service of Legal Process If, for any reason, you want to seek legal action against the LTD Plan, you can serve legal process on Merck Sharp & Dohme Corp. or Merck & Co., Inc. by directing such service to the following address: Merck Sharp & Dohme Corp. Attn: Benefits and Executive Compensation Legal Group 2000 Galloping Hill Road Bldg. K-1 3 rd Floor Kenilworth, NJ 07033 Service of legal process may also be made upon the Plan Sponsor, the Plan Administrator or the Trustee. Plan Funding and Administration The LTD Plan is funded and administered through various sources. The LTD Plan is financed by contributions from the Company and either Before-Tax or After-Tax contributions by participating Eligible Employees. Funds may be held in one or more trusts and used to pay benefits, insurance premiums (if any) and certain LTD Plan expenses. LTD Plan expenses are paid from the Trust unless otherwise paid by the Company from the general assets. The Trustee is: The Bank of New York Mellon Corporation AIM 102-1200 One Wall Street New York, NY 10286 Plan Funding and Administration Chart Official Plan Name and Plan Type and Plan Sponsor Plan Number Benefits Type Claims Administrator Type of Administration Insured or Self-Insured Merck Medical, Dental, Life Insurance and Long Term Disability Plan 502 Welfare/ Long-Term Disability Cigna Contract administration Self-insured by the Company Plan Sponsor: Merck Sharp & Dohme Corp. Plan Type: Employee welfare program providing long-term disability coverage These benefits are self-insured by the Company (and certain affiliates of the Company) and are governed by and subject to ERISA (see Your Rights Under ERISA ). State insurance law does not apply to these benefits. As a result, state-mandated benefits or procedures, if any, do not apply to these benefits. Trust Merck & Co., Inc. is responsible for the funding policy of the trusts and for determining the amount of contributions. The trusts are intended to be tax-exempt under the Internal Revenue Code of 1986, as amended. Merck & Co, Inc. or its subsidiaries may fund additional benefits through the trust(s) at a later time. If a trust is terminated, the assets in the trust will be used to pay all existing liabilities. Any remaining assets may then be used to provide other benefits for employees in accordance with Internal Revenue Code guidelines. In the case of certain highly compensated employees, a portion of benefits payable under the LTD Plan is paid out of the general assets of the Company.

26 No Right to Employment Nothing in this SPD represents or is considered an employment contract, and neither the existence of the LTD Plan nor any statements made by or on behalf of the Company will be construed to create any promise or contractual right to employment or to the benefits of employment. The Company or you may terminate the employment relationship without notice at any time and for any reason. Plan Amendment or Termination The Plan Sponsor reserves the right to amend the LTD Plan in whole or in part or to completely discontinue the LTD Plan or any benefits or eligibility for any benefits at any time. However, following a change in control, as defined in the Merck & Co., Inc. Change in Control Separation Benefits Plan ( the Separation Benefits Plan ), certain limitations apply to the ability of Merck & Co., Inc. or its subsidiaries to amend or terminate the LTD Plan. Amendments may be retroactive; however, no amendment or termination will reduce the amount of any benefit otherwise payable under the LTD Plan for claims incurred prior to the effective date of such amendment or termination. If a benefit is terminated and surplus Plan assets, as determined under ERISA, remain after all liabilities have been paid, such surplus will revert to the Plan Sponsor to the extent permitted under applicable law, unless otherwise stated in the applicable Plan document. If a benefit is terminated and amounts remain which are not ERISA plan assets, such surplus shall revert to the Plan Sponsor. For two years following a change in control (as defined in the Separation Benefits Plan) the material terms of the LTD Plan (including terms relating to eligibility, benefit calculation, benefit accrual, cost to participants, subsidies and rates of employee contributions) may not be modified in a manner that is materially adverse to individuals that participated in the Plan immediately before the change in control. During that two-year period, the Company will pay the legal fees and expenses of any participant who prevails on a claim for relief in an action regarding an impermissible amendment (other than ordinary claims for benefits). Plan Documents This SPD is intended as merely a summary of the official Plan documents and should be retained as part of your permanent records. It does not describe every Plan provision in full detail and it does not alter the Plan or any legal instrument related to the Plan s creation, operations, funding or benefit payment obligations. Every effort has been made to ensure that this SPD accurately reflects relevant Plan provisions currently in effect. However, the Plan documents, which may include insurance contracts and other written agreements with service providers (each of which are held on file with the Plan Sponsor) will govern in the event of any conflict between those documents and this SPD, any verbal representation or with respect to any provision not discussed in this SPD. Plan Year The Plan Year for the LTD Plan begins on Jan. 1 and ends on Dec. 31 of each year. The financial records of the LTD Plan are kept on a calendar-year basis.

27 GLOSSARY This section defines key words that are frequently used in the SPD. These terms are capitalized throughout the SPD. After-Tax Contributions for benefits coverage that are deducted from your pay after federal (and certain state) income and employment taxes are deducted. Base Pay Your annual rate of compensation before any Before-Tax deductions, excluding bonuses, overtime, shift differential, incentives, lump-sum merit increases, non-recurring incentives, commissions and sales cash incentives and other forms of special compensation or other extra pay as determined by the Company in its sole discretion. For employees who are members of covered collective bargaining units, Base Pay includes cost of living adjustments (COLA). For Regular Part-Time Employees, your Base Pay reflects your regularly scheduled hours on the day immediately preceding your date of disability. For example, if the annual pay for the position is $100,000 for a 40-hour work week, and your regularly scheduled hours are 24 hours per week, your Base Pay is $60,000. Before-Tax Contributions for benefits coverage that are deducted from an employee s pay before federal (and certain state) income and employment taxes are deducted. Casual Employee A person who may be called by the Company at any time for employment in the United States on a non-scheduled and non-recurring basis, and becomes an employee of the Company only after reporting to work for the period of time during which the person is working and who is not a Non-Eligible Union Employee and is not an Excluded Person. Claims Administrator Life Insurance Company of North America, a subsidiary of Cigna Corporation; also referred to as Cigna. Company Merck Sharp & Dohme Corp. Disabled See Totally Disabled. Eligibility Period A consecutive 26-week period for which you have been continuously Totally Disabled. For more information, see How the LTD Plan Options Work. Eligible Employees Regular Full-Time Employees, Regular Part-Time Employees, U.S. Expatriates, Merck Temporary Employees and LTD Employees. Eligible Union Employees All U.S.-based employees of the Company who are members of a collective bargaining unit, except those who are members of the United Steelworkers Local 10-00086 collective bargaining unit. ERISA Employee Retirement Income Security Act of 1974, as amended. Evidence of Insurability Proof satisfactory to the Claims Administrator that you are in good health. Also known as statement of good health or proof of insurability. Excluded Employees Casual Employees, Intern/Graduate/Cooperative Student Associates, any class of Excluded Person and Non-Eligible Union Employees. Excluded Person A person who is an independent contractor, or agrees or has agreed to be an independent contractor, or has any agreement or understanding with the Company, or any of its affiliates, not to be an employee or an Eligible Employee, even if previously an employee or Eligible Employee or is employed by a temporary or other employment agency, regardless of the amount of control, supervision or training provided by the Company or its affiliates, or is a leased employee as defined under section 414(n) of the Internal Revenue code of 1986, as amended. An Excluded Person is not eligible to participate in the LTD

28 Plan even if a court, agency or other authority rules that this person is a common-law employee of the Company or its affiliates. Gainful Employment Gainful Employment means compensation (either wages, commissions, earnings, profits or otherwise) for services that would replace at least 60% of your Base Pay prior to your disability in a job that is reasonably available, within up to 75 miles. (The area may be less, depending upon the facts surrounding your disability and the location of your residence when you became Disabled.) A job is reasonably available if an opening exists or the job is being performed within that geographic area, even if there is no current opening. Initial Enrollment Period The 30-day period that starts when you are hired, rehired or transferred (if you qualify as a Transferred Employee), as applicable; or the date of the cover letter provided in your enrollment materials from the Benefits Service Center, whichever is later. Intern/Graduate/Cooperative Student Associate A student hired by the Company as a participant in the Company Intern/Graduate/Cooperative Associate Program. The student must be designated as a participant in that program at least annually by the Company. Legacy OBS Employee An Employee who is coded in the employee data base of Merck & Co., Inc. under Infotype 35 as S1 Legacy Organon, S2 Legacy Intervet or S3 Legacy Nobilon. Legacy Schering Employee An Employee who is coded in the employee data base of Merck & Co., Inc. under Infotype 35 as Legacy S1 Organon, S2 Legacy Intervet or S5 Legacy Schering-Plough or who is a Legacy OBS Employee. Life Event Certain events in your life that may allow you to change some of your benefit choices or coverage levels during the year (e.g., marriage, divorce, birth or adoption of a child, etc.) for plans other than the LTD Plan. LTD Benefits Income replacement benefits provided under the LTD Plan. LTD Employee An employee who is receiving LTD Benefits and, on the day eligibility for LTD Benefits began, was considered by the Company to be a Regular Full-Time Employee, Regular Part-Time Employee, Merck Temporary Employee or a U.S. Expatriate. LTD Employees shall be eligible for coverage as described in this SPD, but eligibility for this coverage may be amended by Merck at any time. LTD Plan The component of the Merck Medical, Dental, Life Insurance and Long Term Disability Plan that provides long-term disability benefits to Eligible Employees. Merck Temporary Employee An employee hired and paid by the Company (rather than an agency) for a specific position in the United States for a designated length of time which is normally not more than 24 consecutive months in duration, who is committed to leave the Company at the end of that time, including an Eligible Union Employee, and who is not a Non-Eligible Union Employee and is not an Excluded Person. Non-Eligible Union Employee An employee of Merck Sharp & Dohme Corp. who is a member of the United Steelworkers Union Local 10-00086 (or its predecessor). Other Income Benefits Sources of income that are offset from your LTD Benefit. They may include, but are not limited to: Social Security Disability or Retirement, Workers Compensation, State Disability benefits, pension, Veterans benefits or any other disability payments from another group insurance policy. See Other Income Sources/Offset section for details. Permitted Plan Change Changes in benefit choices or coverage levels during the year that are consistent with a Life Event and comply with applicable regulations under the Internal Revenue Code and the guidelines established by the Plan Administrator (subject to periodic change) for plans other than the LTD Plan.

29 Physician A person licensed to practice medicine in the jurisdiction where such services are performed; or any other person whose services, according to applicable law, must be treated as Physician s services for purposes of the Long Term Disability Plan. Each such person must be licensed in the jurisdiction where the service is performed and must act within the scope of that license. Such person must also be certified and/or registered if required by such jurisdiction. The term does not include: You Your spouse, or Any member of your immediate family including your and/or your spouse s: Parents Children (natural, step or adopted) Siblings Grandparents, or Grandchildren. Plan See definition of LTD Plan. Plan Administrator Merck Sharp & Dohme Corp. Plan Sponsor Merck Sharp & Dohme Corp. Plan Year The calendar year, Jan. 1 through Dec. 31, on which the records of the Plan are kept. Regular Full-Time Employee An employee employed by the Company in the United States on a scheduled basis for a normal work week, including an Eligible Union Employee, who is not classified as Part-Time, Merck Temporary or Casual, is not a Non-Eligible Union Employee and is not an Excluded Person. Regular Part-Time Employee An employee employed by the Company in the United States on a scheduled basis for less than the number of regularly scheduled hours for a Company site, including an Eligible Union Employee, who is not a Non-Eligible Union Employee and is not an Excluded Person. Rehabilitative Employment Rehabilitative Employment means work in any gainful occupation for which you are reasonably suited by training, education or experience. SPD Summary Plan Description. Totally Disabled (or Total Disability ) Totally Disabled means you are unable to perform all material aspects of your occupation during the Eligibility Period and during the first 24 consecutive months that benefits are paid under the LTD Plan. After the first 24 consecutive months of disability, you are Totally Disabled if you are unable to engage in any Gainful Employment for which you are or may become reasonably qualified by education, training or experience. You must be under the regular care of a licensed doctor to be considered Totally Disabled. The doctor must also have appropriate expertise for your disability and you must follow the prescribed course of treatment. For example, it is not normal and appropriate for a general practitioner to treat depression. You cannot receive any compensation or profit for any work performed (including from entities other than Merck). However, you can do rehabilitative work that is approved by the Claims Administrator. For more information, see Rehabilitative Employment. Transfer Date The date a Transferred Employee becomes an Eligible Employee.

30 Transferred Employee An employee of Merck (or its subsidiaries) who is transferred to a position as a Regular Full-Time Employee or a Regular Part-Time Employee and who is not an Excluded Person and who on the day before the employee s transfer was not an Eligible Employee. U.S. Expatriate A U.S. citizen or individual with U.S. Permanent Resident status who is employed by a foreign subsidiary of the Company as a foreign service employee, provided that the individual has not elected coverage under any retirement plan of the foreign subsidiary if the subsidiary is covered by an agreement entered into by the Company under Section 3121(l) of the Internal Revenue Code (dealing with Social Security benefits) and who is not an Excluded Person.

31 EXHIBIT A This section lists the collective bargaining units whose members are eligible to participate in long-term disability benefits under the Merck Medical, Dental, Life Insurance and Long Term Disability Plan as described in this SPD. International Association of Machinists and Aerospace Workers, District 15, Lodge 315 (Summit, Kenilworth/Union, New Jersey) International Chemical Workers Union Council of the United Food and Commercial Workers Union, Local 194-C (Memphis, TN) (only with respect to employees receiving LTD Benefits as of the date of the closing of the sale of Merck s consumer care business to Bayer AG) International Brotherhood of Teamsters, Local 107 (West Point, PA) United Steelworkers Union, Local 4-575 (Rahway, NJ) International Chemical Workers Union Council of the United Food and Commercial Workers Union, Local 94C (Elkton, VA) Mid-Atlantic Regional Joint Board, Workers United, Local 1398 (Elkton, VA) The Office and Professional Employees International Union, Local 1937, AFL-CIO, CLC (West Point, PA) United Steelworkers, Local 10-580 (Danville, PA) International Union of Operating Engineers, Local 68 (Rahway, NJ)

32 EXHIBIT B If your Long Term Disability commenced between the following dates please contact the following disability carrier to request information about your coverage: Legacy Schering-Plough If Legacy Schering-Plough LTD Start Date Between: Contact Phone Number Contract Number Jan. 1, 1986 Dec. 31, 1996 Jan. 1, 1997 Dec. 31, 2004 Jan. 1, 2005 Present Metropolitan Life Insurance Company MetLife Disability PO Box 14590 Lexington, KY 40512 Liberty Life Assurance Company of Boston Liberty Mutual PO Box 7213 London KY 40742-9969 Claims Administrator for the Long Term Disability Plan Cigna Group Insurance Long Term Disability P.O. Box 22308 Pittsburgh, PA 15222-0308 1-800-300-4296 1-888-437-7611 830-030300 1-800-238-2125 986049 986051 986055 986056 980019 Legacy Organon If Legacy Organon LTD Start Date Between: Contact Phone Number Policy Number Jan. 1, 2007 Dec. 31, 2008 The Hartford PO Box 14305 Lexington, KY 40512-4305 1-800-752-9713 675800G

The information contained herein has been provided by Merck & Co., Inc. (and its subsidiaries) and is solely the responsibility of Merck & Co., Inc. (and its subsidiaries). 3.MK-H-554H.108