John Kimelman is a veteran financial journalist who spent 14 years as an executive editor at Barrons.com. In that role, he supervised a staff of writers, edited and wrote online columns, and wrote feature articles and cover stories for Barronâs magazine. Previously, he worked as a staff editor and writer at CNBC.com and American Banker, the leading trade publication of the U.S. commercial banking industry.
David Schepp is a veteran financial journalist with more than two decades of experience in financial news editing and reporting for print, digital, and multimedia publications.
Medicare is a federal health insurance program primarily for people age 65 and older. It also covers certain younger individuals with disabilities, including those who have received Social Security Disability Insurance for at least 24 months or who have specific medical conditions such as ALS or end-stage renal disease.
When can you sign up for Medicare?
Most people can sign up for Medicare during a seven-month initial enrollment period that begins three months before the month they turn 65, includes their birth month, and ends three months afterward. Coverage typically begins based on when you enroll within that window.
What do the different parts of Medicare cover?
Medicare is divided into four parts. Part A covers hospital care, Part B covers doctor visits and other medical services, Part C (Medicare Advantage) is a private-plan alternative that bundles coverage, and Part D helps cover prescription drugs.
Medicare is a health insurance plan administered by the U.S. federal government for those age 65 or older. President Lyndon B. Johnson signed the program into law on July 30, 1965. Medicare is distinct from Medicaid, a joint federal and state program that provides health coverage to U.S. residents with limited income and resources, regardless of age.
Youâre eligible to sign up for Medicare starting three months before the month you turn 65, with coverage beginning on the first day of your birth month. You may also qualify for Medicare earlier if you have been receiving Social Security Disability Insurance (SSDI) for at least 24 months or if you have amyotrophic lateral sclerosis (ALS, also known as Lou Gehrigâs disease). People with end-stage renal disease (permanent kidney failure) may also qualify regardless of age, subject to specific enrollment rules.
Key Points
Medicare is a federal health insurance plan for adults 65 and older.
The basic building blocks of the program are parts A, B, C, and D.
One key decision is whether to choose Original Medicare or a Medicare Advantage plan, as coverage options and costs can vary considerably.
Unlike employer-sponsored health insurance, which typically covers spouses under the same plan, Medicare doesnât offer family plans for married couples. As a result, you and your spouse each choose a plan based on your individual health needs.
But before tackling that decision, itâs necessary to understand the basic building blocks of a Medicare plan: parts A, B, C, and D.
Medicare Part A: Hospital insurance
This plan is the part of Medicare that covers the biggest ticket health care cost: hospitalization due to illness or surgery. Part A also covers skilled nursing facility care, hospice care, and some home health care.
Best of all, thereâs usually no premium (or cost) for Part A, because most Medicare beneficiaries already paid for this program through the Medicare taxes deducted from their paychecks over the years. If you donât qualify for a premium-free Part A because you didnât work long enough, you can usually buy it by paying a monthly premium.
Medicare Part B: Medical insurance
This plan covers:
Services from doctors and other health care providers, including physical therapy
Outpatient care
Limited home health care
Durable medical equipment (such as wheelchairs, walkers, and hospital beds)
Many preventive services (such as screenings, shots, vaccines, and yearly âwellnessâ visits)
The government pays about 75% of the cost of Part B, but you must pay the rest. The basic monthly premium was set at $202.90 for 2026, due each month, and most beneficiaries pay coinsurance after meeting the annual deductible ($283 in 2026).
For 2026, Part B premiums are higher for beneficiaries with greater income. Depending on your modified adjusted gross income (MAGI) from two years earlier, you may owe an income-related monthly adjustment amount (IRMAA) that raises your Part B premium above the standard $202.90. For example, single filers with MAGI above $109,000 and joint filers above $218,000 pay rising total premiums that top out at $689.90 per month at the highest income tier.
The Social Security Administration (which oversees Medicare) will inform you if you need to pay the additional IRMAA premium. The surcharge will be included on your Medicare invoices, which are mailed to your home or available on your online Medicare account at medicare.gov. And if a life-changing event has reduced your reported household income, you can request an IRMAA reduction from the Social Security Administration.
Medicare Part C: Medicare Advantage
Part C is synonymous with Medicare Advantage. Unlike the Original Medicare program thatâs run exclusively by the federal government, Medicare Advantage plans are offered by more than a dozen companies, including health care sector giants UnitedHealth Group (UNH), Cigna (CI), Humana (HUM), Aetna, and the nonprofit Blue Cross Blue Shield Association.
These bundled plans, which serve as an alternative to Original Medicare, include the benefits found in Part A, Part B, and usually Part D. They can also include benefits such as vision and dental services that Original Medicare doesnât provide.
Medicare Part D: Drug coverage
Part D helps to cover the cost of prescription drugs, including many recommended shots and vaccines. These drug plans are operated by private insurers under rules approved by the federal Medicare program. You can enroll in Part D by adding a stand-alone drug plan to Original Medicare (Parts A and B) or by choosing a Medicare Advantage plan that includes drug coverage. As with Part B, higher-income beneficiaries may pay an additional income-related amount.
What is a Medicare Supplement Insurance (Medigap) policy, and do you need it?
Medicare hospital (Part A) and medical insurance (Part B) doesnât usually cover all costs. You may receive bills from doctors and other health care for services not fully covered. For this reason, many insurance providers offer Medicare Supplement Insurance policies.
This added layer of insurance, also known as Medigap and sold only by private insurers, fills the gaps in Original Medicare coverage by paying bills for various medical services, office co-payments, and deductibles, amounts typically paid by you (the policyholder) before insurance kicks in.
Medigap isnât available to people enrolled in Medicare Advantage (Part C) plans, which combine Part A and Part B coverage into a single policy.
The big decision: Original Medicare or Medicare Advantage?
The initial enrollment period for Medicare lasts seven months: three months before your 65th birthday, your birth month, and three months after. Seven months might seem like plenty of time, but starting early lets you explore your options and avoid processing delays.
Although choosing a Medicare plan can seem intimidating, the process for signing up for these programs is fairly simple. Whether you choose Original Medicare or an Advantage plan, the first step is to sign up for Medicare parts A and B. The simplest and fastest way is to visit the Social Security Administration website (ssa.gov). To sign up for Medicare, youâll need to create your secure âmy Social Securityâ account, if you donât have one already.
You can also apply in person at a Social Security Administration office (wait times vary by location) or set up an appointment to enroll with a Medicare official by calling 800-772-1213. Be aware that appointments may be scheduled several weeks out.
Once youâve submitted an application, you can expect to receive your red, white, and blue Medicare card within a few weeks. It includes a unique Medicare number that youâll need to enroll in additional coverage options such as supplemental insurance, drug plans, and Medicare Advantage.
The bottom line
Americaâs two leading political parties seldom find common ground, but most Republicans and Democrats strongly support Medicare. The federal program is a vital resource that puts health care within reach for millions of older adults.
The advent of Medicare Advantage plans in the late 1990s brought some added complexity to the program, but it also provided seniors with a wider array of choices. If youâre approaching your initial enrollment period, it pays to compare Original Medicare with Medicare Advantage plans. Knowing the benefits, costs, and coverage optionsâand how they fit into your budgetâcan help ensure your health care needs are met.
