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JAMA Patient Page
July 28, 2015


JAMA. 2015;314(4):420. doi:10.1001/jama.2015.8049

This year marks the 50th anniversary of the creation of Medicare and Medicaid.

The Social Security Amendments of 1965 established Medicare and Medicaid in the United States. Medicare is a federal program that provides health insurance coverage to people aged 65 years or older and younger people with permanent disabilities. Medicare-covered benefits are organized into 4 parts. Medicare Part A covers inpatient hospitalizations, short-term stays in skilled nursing facilities, some home health care, and hospice care. Medicare Part B covers outpatient services, including doctor’s appointments, medical equipment, laboratory tests, and preventive care such as vaccinations and cancer screenings. Together, Medicare Parts A and B are sometimes referred to as original or traditional Medicare.

Medicare Part C, also known as Medicare Advantage, is a program that allows beneficiaries to enroll in private health plans, such as health maintenance organizations and preferred provider organizations, to receive Medicare-covered benefits. These Medicare-approved private plans provide all benefits covered under Parts A and B, and many plans offer other benefits like vision and dental services. The majority of plans also provide Part D prescription drug coverage. Additionally, Medicare Advantage plans are required to place a limit on beneficiaries’ out-of-pocket expenses for Medicare Parts A and B covered services of $6700 in 2015; in contrast, there is no out-of-pocket limit in traditional Medicare. Potential down sides of Medicare Advantage include possible restrictions to doctors that are in network, requirements for a referral from a primary care doctor before seeing a specialist, and potentially higher monthly premiums than those with traditional Medicare.

Medicare Part D covers outpatient prescription drugs for beneficiaries who enroll in Medicare-approved private drug plans—either stand-alone prescription drug plans for beneficiaries enrolled in traditional Medicare or Medicare Advantage drug plans.

Individuals should be aware that Medicare pays only for medically necessary nursing home care such as assistance with intravenous medications and wound care. To qualify for skilled nursing home care, patients need to have had a recent inpatient stay of 3 or more days, require skilled care for a condition related to their hospitalization, and obtain skilled care at a facility that is Medicare certified.

Medicare will not pay for long-term nursing home care for help with daily activities, such as eating or using the restroom. Patients needing these services may qualify for financial assistance from Medicaid. Additional information about paying for long-term nursing home care can be found at

Eligibility for Medicare

Individuals are eligible to sign up for Medicare Part A and Part B if they (1) are aged 64 years and 9 months or older or (2) are younger than 65 years with end-stage renal disease or amyotrophic lateral sclerosis (ALS) or have a long-term disability (eg, multiple sclerosis, chronic heart failure) and have received Social Security Disability Insurance payments for 24 months.

People are eligible for Medicare Advantage (Part C) if they have or are entitled to Part A and enrolled in Part B. Medicare Part D is available on a voluntary basis to any beneficiary enrolled in either Medicare Part A or Part B.

Enrolling in Medicare

People are automatically enrolled in Medicare Parts A and B if they have received Social Security or Railroad Retirement Board benefits, are younger than 65 years and have received disability benefits for 24 months, or have received benefits related to an ALS diagnosis. However, those who become eligible for Medicare and have yet to retire and receive federal benefits or people qualifying because of end-stage renal disease need to sign up for Medicare.

Enrollment can occur during 3 different times.

  • The initial enrollment period is the 7 months around a person’s 65th birthday. For example, if your birthday is July 14, this period includes the 3 months before July (April-June), the month you turn 65 (July), and the 3 months after July (August-October).

  • The general enrollment period allows eligible individuals who did not sign up during initial enrollment to join each year between January 1 and March 31. Signing up during this period often results in a late enrollment penalty and a higher premium than those who joined during initial enrollment.

  • Finally, a special enrollment period is available to certain individuals who qualify, such as after loss of employer-based coverage for those who are Medicare eligible.

Individuals not automatically enrolled in Medicare may sign up through Social Security online (, by telephone (1-800-772-1213), or in person at their local Social Security office.

Because Medicare Part D is optional, most people who are interested in this coverage must sign up themselves. Outside of their initial enrollment period for Medicare, beneficiaries can enroll in a Medicare Part D or Medicare Advantage plan (or switch from one plan to another) each year between October 15 and December 7. Additional information about Medicare Advantage (Part C) and Part D and instructions for signing up can be found at and

The JAMA Patient Page is a public service of JAMA. The information and recommendations appearing on this page are appropriate in most instances, but they are not a substitute for medical diagnosis. For specific information concerning your personal medical condition, JAMA suggests that you consult your physician. This page may be photocopied noncommercially by physicians and other health care professionals to share with patients. To purchase bulk reprints, call 312/464-0776.
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Article Information

Sources: Centers for Medicare & Medicaid Services, US Department of Health and Human Services, US News & World Report, Social Security Administration

Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Rajaram reports grants from the Agency for Healthcare Research and Quality and Merck and nonfinancial support from the American College of Surgeons Clinical Scholars in Residence program.

Topic: Health Care Delivery