Medicare Part A · Hospital Insurance
Plain English. Five calm steps. No pressure.
Part A is the hospital half of Original Medicare. For most people it costs nothing each month — but when and how you sign up still matters. Here's everything you need, in the order you need it.
Free · Private · About a 10-minute read
Your Part A Path
Read them in order, or jump straight to what you need.
Know what Part A pays for — and what it doesn't.
Check whether you'll pay a monthly premium.
Find your sign-up window — and avoid costly gaps.
Three easy ways, plus a checklist of what to have ready.
2026 costs, and how people cover what Part A leaves behind.
Step 1 What It Covers
Part A = Hospital Insurance
Think of Part A as the "when you're admitted" part of Medicare. It helps pay when you're formally admitted as a hospital inpatient, and for certain care that follows.
Your room, meals, nursing care, and drugs given during a hospital stay when you're formally admitted.
Short-term skilled care (like rehab) after a qualifying hospital stay of at least 3 inpatient days — up to 100 days per benefit period.
Comfort-focused care for people with a terminal illness, usually provided at home.
Some part-time skilled care at home, such as nursing or therapy, when you qualify.
What Part A does not cover: doctor visits, outpatient care, and lab work (that's Part B); most prescriptions you fill at a pharmacy (that's Part D); and long-term custodial care in a nursing home, like help with bathing and dressing.
Good to know: staying in the hospital "under observation" counts as outpatient care, not inpatient — even overnight. Always ask the hospital whether you've been admitted.
Step 3 When to Enroll
Your Initial Enrollment Period
Your first chance to sign up is a 7-month window built around your 65th birthday. Sign up in the 3 months before your birthday month, and coverage starts on the first day of your birthday month — no gap.
You'll usually be enrolled in Parts A and B automatically. Your red, white and blue Medicare card arrives about 3 months before you turn 65.
Nothing to do — watch your mailIf you have health coverage from your (or your spouse's) current job, you can take premium-free Part A now and delay Part B — or delay both — with no penalty. You'll get an 8-month Special Enrollment Period after the job or coverage ends.
Special Enrollment PeriodThe General Enrollment Period runs January 1 – March 31 each year. Coverage starts the month after you sign up. If you qualify for premium-free Part A, you can sign up any time after your window opens.
Jan 1 – Mar 31You're generally enrolled automatically after 24 months of Social Security disability benefits. People with ALS are enrolled when disability benefits start. Kidney failure (ESRD) has its own rules.
Usually automaticHave a Health Savings Account (HSA)? You can't contribute to an HSA once Part A starts — and when you sign up after 65, Part A can be backdated up to 6 months. Stop HSA contributions 6 months before you apply to avoid a tax penalty. Ask your HR department or tax advisor if you're unsure.
Step 4 How to Sign Up
You Enroll Through Social Security
Part A comes from the federal government, so you sign up with Social Security — not with an insurance company or an agent. Pick whichever way feels most comfortable.
Takes about 10 minutes. You can save and come back. You don't need to start your retirement benefits to apply for Medicare.
Call Social Security Monday–Friday, 8 a.m. to 7 p.m. local time. Mornings and later in the week are usually less busy.
1-800-772-1213
TTY 1-800-325-0778
Visit your local Social Security office. Calling ahead for an appointment can save you a long wait.
Have these ready before you start:
Worked for a railroad? Sign up through the Railroad Retirement Board instead, at 1-877-772-5772.
Medicare will never call you to ask for your Medicare or Social Security number.
Step 5 Costs & Next Steps
"Premium-Free" Isn't "Cost-Free"
Even with a $0 premium, you share the cost when you're admitted. These amounts apply per benefit period — which starts when you're admitted and ends after you've been out of the hospital or skilled nursing facility for 60 days in a row.
| When you're admitted | You pay |
|---|---|
| Hospital stay | |
| Deductible (once per benefit period) | $1,736 |
| Days 1–60 | $0 after deductible |
| Days 61–90 | $434 per day |
| Days 91+ (60 lifetime reserve days) | $868 per day |
| After lifetime reserve days are used | All costs |
| Skilled nursing facility | |
| Days 1–20 | $0 |
| Days 21–100 | $217 per day |
| Days 101+ | All costs |
Source: Centers for Medicare & Medicaid Services, 2026 Medicare Parts A & B premiums and deductibles. 2027 amounts are usually announced in mid-November.
Part A has no yearly out-of-pocket limit, and it doesn't cover doctors or prescriptions. That's why most people pair it with other coverage. Here are your main paths — learn about each, then decide for yourself.
Medical insurance for doctor visits, outpatient care, and preventive services. Most people sign up for A and B together.
Keep Original Medicare and add a Medicare Supplement to help with costs like the $1,736 deductible, plus a separate drug plan.
A private plan that bundles Parts A and B (and usually D), with a yearly out-of-pocket maximum and a provider network.
Learn first. Compare when you're ready. Enroll yourself.
Common Questions
For most people, yes. If you or your spouse worked and paid Medicare taxes for at least 40 quarters (about 10 years), there's no monthly premium. In 2026, people with 30–39 quarters pay $311 a month, and people with fewer than 30 quarters pay $565 a month. You still pay the deductible and coinsurance when you use hospital care.
If you already get Social Security or Railroad Retirement benefits at least 4 months before you turn 65, you're usually enrolled in Parts A and B automatically. Your Medicare card arrives about 3 months before your 65th birthday. If you're not collecting benefits yet, you'll need to sign up yourself.
Many people still working take premium-free Part A at 65, since it costs nothing and can act as secondary coverage. The main exception is if you're contributing to an HSA — you can't contribute once Part A begins, and Part A can be backdated up to 6 months. Talk with your employer's benefits team about how your plan works with Medicare.
Only for people who must pay a Part A premium. If you don't sign up when first eligible, the premium can rise 10%, for twice the number of years you went without it. If your Part A is premium-free, there's no Part A late penalty — but Part B has its own late penalty, so check that separately.
No — Part A enrollment happens only through Social Security (or the Railroad Retirement Board). Once you have Parts A and B, this site can help you learn about and compare Medicare Advantage, Medigap and Part D plans, and enroll yourself when you're ready.
Part A covers you when a doctor formally admits you as an inpatient. If you're in the hospital "under observation," you're an outpatient — even if you stay overnight — and Part B rules apply. Ask the hospital staff about your status, especially if you may need skilled nursing care afterward.
Still have a question? Just ask.
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Education First. Enrollment Second.