Medicare · Supporting
What Medicare is, who qualifies, and how the four parts work
Last reviewed September 18, 20264 min readBy the Goodsurance editorial team Reviewed by the Goodsurance editorial team
Medicare is a federal health insurance program administered by the Centers for Medicare and Medicaid Services (CMS). Congress created it in 1965 to give older Americans and people with certain disabilities reliable access to medical care regardless of income. It covers roughly 67 million people today.
What Medicare is
Two broad categories of people qualify:
- Age 65 or older and a U.S. citizen or permanent resident who has lived in the country for at least five continuous years.
- Under 65 with a qualifying disability after a 24-month period of receiving Social Security Disability Insurance (SSDI) benefits, end-stage renal disease (ESRD), or amyotrophic lateral sclerosis (ALS), which carries its own timing rules.
Medicare is not the same as Medicaid. Medicaid is a joint federal-state program based on income and assets; Medicare eligibility is primarily age- and work-history-based, and income affects cost, not access.
The four parts of Medicare
Medicare is organized into four lettered parts, each covering a distinct category of care.
Part A: hospital insurance. Part A covers inpatient hospital care, skilled nursing facility (SNF) care following a qualifying 3-day formal inpatient hospital admission (observation stays are billed under Part B and do not count toward that threshold), some home health care, and hospice. Most people pay no Part A premium because they or a spouse worked at least 40 quarters, roughly 10 years, in Medicare-taxed employment. People with fewer quarters can buy in: in 2026, the buy-in premium is $311 per month with 30 to 39 quarters of coverage, or $565 per month with fewer than 30 quarters. The 2026 inpatient hospital deductible is $1,736 per benefit period, not per calendar year, meaning two separate hospitalizations in one year can each trigger it.
Part B: medical insurance. Part B covers outpatient services including doctor visits, preventive screenings, durable medical equipment, and most treatments delivered outside a hospital. In 2026, the standard Part B premium is $202.90 per month and the annual deductible is $283. After the deductible, Medicare pays 80% of the approved amount; the beneficiary pays the remaining 20% with no annual cap on that amount. Higher-income beneficiaries pay a surcharge called IRMAA (Income-Related Monthly Adjustment Amount). In 2026, IRMAA begins above $109,000 in modified adjusted gross income (MAGI) for a single filer or $218,000 for married couples filing jointly; people above those thresholds pay more through a tier structure, and the surcharge applies to both Part B and Part D.
Part C: Medicare Advantage. Part C, also called Medicare Advantage, is an alternative to Original Medicare delivered through a private insurer that CMS approves and pays. Most Advantage plans bundle Part D drug coverage and may include additional benefits. In 2026, the federal out-of-pocket maximum (MOOP) for in-network care is $9,250; the combined in-network and out-of-network cap is $13,900. Individual plans may set lower limits. To find out more about coverage options in your area, please contact us to discuss plan options.
Part D: prescription drug coverage. Part D is optional stand-alone drug coverage available through private insurers. In 2026, no Part D plan may set a deductible above $615, and the annual out-of-pocket cap on covered drugs is $2,100. Once you reach that cap, covered formulary drugs cost $0 for the rest of the calendar year.
Part A monthly premium by work history
Most people pay nothing because they or a spouse worked at least 40 quarters in Medicare-taxed jobs. People with fewer quarters can buy Part A at the monthly amounts shown.
Covered drugs cost nothing after this
How enrollment works
People already receiving Social Security or Railroad Retirement Board (RRB) benefits at least four months before turning 65 are enrolled automatically in both Part A and Part B. The Welcome to Medicare package arrives in the mail; if you do not want Part B because you have qualifying employer coverage, you must actively decline it following the instructions in that package. People living in Puerto Rico who qualify for automatic enrollment receive Part A only and must actively enroll in Part B to obtain that coverage.
People not yet drawing Social Security must enroll on their own. The Initial Enrollment Period (IEP) spans seven months: the three months before your 65th birthday month, the birthday month itself, and the three months after.
Missing the IEP without qualifying coverage triggers permanent penalties. The Part B late-enrollment penalty adds 10% to your premium for each full 12-month period you went without Part B. The Part D penalty adds 1% of the national base beneficiary premium for each full month without creditable drug coverage; the penalty clock starts after 63 or more consecutive days without creditable coverage, and the penalty is added to your monthly Part D premium for as long as you have the plan.
One timing issue that surprises many people: any Medicare enrollment, including premium-free Part A, ends your eligibility to contribute to a Health Savings Account (HSA). Because Part A can backdate enrollment by up to six months, stopping HSA contributions before enrolling is important to avoid IRS penalties.
What Medicare does not cover
Original Medicare (Parts A and B) does not cover most dental care, routine vision exams, hearing aids, or long-term custodial care. Some Medicare Advantage plans include these benefits, but coverage, limits, and cost-sharing vary by plan and are not guaranteed. Medigap policies, sold by private insurers and standardized by federal and state rules, can help cover costs such as the Part B 20% coinsurance and the Part A inpatient deductible. The guaranteed-issue window to buy a Medigap policy without medical underwriting is six months, beginning the month you turn 65 and are enrolled in Part B. Outside that window, insurers in most states may use health questions to price or deny coverage.
Common questions about Medicare
Quick answers, fast .
Tap any question to expand. Each links to a fuller standalone answer.
Does Medicare pay for hearing aids
Original Medicare does not cover hearing aids or fittings.
Some Medicare Advantage plans may include a hearing benefit, but what they cover varies by plan.
Does Medicare cover diabetes supplies and testing?
Yes.
In 2026 Medicare covers most diabetes care across two parts. Part B (outpatient care and equipment) covers blood sugar monitors, test strips, lancets, and continuous glucose monitors (CGMs) as durable medical equipment, plus diabetes screenings and a self-management training program. You pay 20% of the Medicare-approved amount after the $283 Part B deductible. Part D (drug coverage) covers insulin and related supplies like syringes, and in 2026 your insulin is capped at $35 for a month's supply. If you have a Medicare Advantage plan, it covers at least the same diabetes benefits, sometimes with added extras.
Does Medicare cover vision care?
Mostly no for routine care.
In 2026, Original Medicare does not cover routine eye exams for glasses or contact lenses, and it does not pay for the glasses or contacts themselves. It does cover some medical eye care: yearly glaucoma screenings for people at high risk, diabetic retinopathy exams, treatment for eye diseases, and cataract surgery (including one pair of standard glasses or contacts afterward). For those covered services you pay 20% after the $283 Part B deductible. Many Medicare Advantage plans add a routine vision benefit covering eye exams and an allowance for glasses.
Does Medicare cover durable medical equipment?
Yes.
Medicare Part B covers durable medical equipment (DME): reusable medical gear your doctor prescribes for use at home, such as wheelchairs, walkers, hospital beds, oxygen equipment, CPAP machines, and blood sugar monitors. You pay 20% of the Medicare-approved amount after the $283 Part B deductible in 2026, and Medicare pays the other 80%. To be covered, the item must be ordered by a Medicare-enrolled doctor and supplied by a Medicare-enrolled supplier, and some items are rented rather than bought. Equipment meant mainly for use outside the home, or only for comfort or convenience, is not covered.
Does Medicare cover ambulance services?
Yes, in limited situations.
Medicare Part B covers emergency ambulance transportation when traveling any other way could endanger your health, taking you to the nearest appropriate hospital or facility. You pay 20% of the Medicare-approved amount after the $283 Part B deductible in 2026. Air ambulance is covered only when ground transport cannot reach you or would take too long. Non-emergency ambulance trips, for example to dialysis, are covered only when a doctor provides a written order stating they are medically necessary. Medicare does not cover ambulance rides taken purely for convenience.
Does Medicare cover chiropractic care?
Partly.
Medicare Part B covers one specific chiropractic service: manual manipulation of the spine to correct a subluxation (when one or more bones of the spine are out of position) that a doctor confirms is medically necessary. You pay 20% of the Medicare-approved amount after the $283 Part B deductible in 2026. Medicare does not cover other services a chiropractor might offer, such as X-rays, massage therapy, acupuncture, or routine wellness visits, so you would pay the full cost for those. Some Medicare Advantage plans include extra chiropractic or wellness benefits beyond this.
Does Medicare cover mental health services?
Yes.
Medicare covers mental health care across its parts in 2026. Part B covers outpatient services like therapy, counseling, and visits with psychiatrists, psychologists, and clinical social workers, and since 2024 it also covers marriage and family therapists and mental health counselors. You pay 20% of the Medicare-approved amount after the $283 deductible, and one depression screening each year is free. Part A covers inpatient mental health care, with a lifetime limit of 190 days in a freestanding psychiatric hospital. Part D covers most mental health medications. Many of these services are also available by telehealth, and Medicare Advantage plans cover at least the same benefits.
Does Medicare cover hearing aids?
Original Medicare does not cover hearing aids or the exams used to fit them.
Some Medicare Advantage plans include a hearing benefit, but coverage varies by plan.
Does Medicare cover physical therapy?
Yes.
Medicare Part B covers outpatient physical therapy that is medically necessary to treat your condition. You pay 20% of the Medicare-approved amount after the yearly Part B deductible ($283 in 2026). There is no longer a hard dollar cap on therapy, but once your physical and speech therapy together pass $2,480 in 2026, your therapist must add a note (called a KX modifier) confirming you still need care. Claims above $3,000 may be reviewed for medical necessity. Part A covers physical therapy you receive as a hospital inpatient or in a skilled nursing facility. A doctor or therapist must set up and regularly review your plan of care.
What is the difference between Original Medicare and Medicare Advantage?
Original Medicare is the government-run program made up of Part A (hospital) and Part B (medical), letting you see any doctor or hospital nationwide that accepts Medicare, with no network.
Medicare Advantage (Part C) delivers those same benefits through a private plan, usually within a provider network, and often bundles prescription drug coverage plus extras like dental and vision. With Original Medicare you typically pay the Part B premium ($202.90 per month in 2026), the Part B deductible ($283 in 2026), and 20 percent of many costs with no annual out-of-pocket cap, which is why many people add a Medigap (supplement) policy and a separate Part D drug plan. Medicare Advantage usually has a lower or $0 plan premium and a yearly out-of-pocket maximum, but uses networks and may require prior approval. Which fits depends on your doctors, prescriptions, and budget.
Can I see out-of-network doctors on a Medicare Advantage PPO?
Yes.
A Medicare Advantage PPO (Preferred Provider Organization plan, where your Medicare benefits come through a private plan) lets you see doctors and hospitals outside the plan's network, but you usually pay more for out-of-network care than for in-network care. Staying in network keeps your costs lower, while going out of network is allowed and can be worth it if you want a specific provider. This flexibility is a key difference from a Medicare Advantage HMO (Health Maintenance Organization plan), which generally only covers in-network care except in emergencies. With a PPO, you also typically do not need a referral to see a specialist. Keep in mind the provider must accept the plan and Medicare. Emergency and urgent care are covered regardless of network on both plan types. The trade-off with a PPO is more freedom in exchange for generally higher costs than an HMO.
Which is better, Medigap or Medicare Advantage?
Neither is better for everyone; they suit different needs.
Medigap (also called Medicare Supplement, a private policy that pairs with Original Medicare) lets you see any doctor nationwide who accepts Medicare with no network and very predictable out-of-pocket costs, but you pay a monthly Medigap premium and add a separate Part D drug plan. Medicare Advantage (Part C, your Medicare benefits through a private plan) often has a lower or $0 plan premium, bundles drug coverage and extras like dental and vision, and caps your yearly out-of-pocket costs, but uses provider networks and may require prior approval. People who travel, want maximum doctor freedom, and prefer steady costs often lean Medigap; people who want low premiums, extras, and a network they are comfortable with often lean Medicare Advantage. With both, you still pay the Part B premium ($202.90 per month in 2026).