# Medicare Part A vs. Part B differences come down to this: Part A is hospital insurance that covers inpatient care (and is usually premium-free), while Part B is medical insurance that covers doctor visits and outpatient care for a monthly premium ($185/month in 2026 for most people).
If you are turning 65, this is the first fork in the road. Getting it right protects you from coverage gaps and late-enrollment penalties. Here are the 7 differences that actually matter ([learn more about the 12 best ways to live happy, healthy, and wealthy in retirement in 2026 and beyond](/articles/the-12-best-ways-to-live-happy-healthy-and-wealthy-in-retirement-in-2026-and-beyond-918924)).
## 1. What each part covers
**Part A (Hospital Insurance)** covers inpatient hospital stays, skilled nursing facility care, hospice, and some home health care. Think "admitted to the hospital overnight."
**Part B (Medical Insurance)** covers doctor visits, outpatient care, preventive services, lab tests, durable medical equipment, and most vaccines. Think "everything outside the hospital bed."
The two are designed to work together — Part A handles the room, Part B handles the physician who treats you in it.
## 2. What each part costs
This is the biggest practical difference:
- **Part A is premium-free** for about 99% of beneficiaries, because you (or a spouse) paid Medicare taxes for at least 40 quarters (10 years) of work. If you didn't, the 2026 premium can run up to $518/month.
- **Part B has a standard monthly premium of $185 in 2026**, deducted from most people's Social Security check. Higher earners pay more through IRMAA (income-related surcharges).
## 3. Deductibles and cost-sharing
- **Part A** uses a per-benefit-period deductible ($1,676 in 2026) that covers your first 60 days in the hospital. After day 60, daily coinsurance kicks in.
- **Part B** has a lower annual deductible ($257 in 2026), after which you typically pay 20% of the Medicare-approved amount for most services — with no annual out-of-pocket cap under Original Medicare.
That missing out-of-pocket cap is why many beneficiaries add a Medigap policy or choose Medicare Advantage.
## 4. Enrollment: automatic vs. active
- If you already collect Social Security before 65, you are usually **enrolled in both Part A and Part B automatically**.
- If you are not yet collecting Social Security, you must **actively sign up** during your 7-month Initial Enrollment Period (the 3 months before your 65th birthday month, the month itself, and the 3 months after).
Miss it, and Part B can carry a lifelong late-enrollment penalty of 10% for each 12-month period you delayed.
## 5. When you can delay without penalty
Part A is almost always worth taking at 65 since it's free. Part B is where timing matters:
- If you have **creditable employer coverage** (from your job or a spouse's active employment), you can usually delay Part B penalty-free and enroll later through a Special Enrollment Period.
- **Retiree coverage, COBRA, and marketplace plans do NOT count** as creditable for this purpose — a common and costly mistake.
## 6. How they fit into the bigger Medicare picture
Parts A and B together are called **Original Medicare**. From there:
- **Part C (Medicare Advantage)** bundles A and B (usually plus drug coverage) through a private plan.
- **Part D** adds prescription drug coverage.
- **Medigap** supplements Original Medicare by covering much of the 20% Part B leaves behind.
You must be enrolled in both Part A and Part B before you can buy a Medigap or Medicare Advantage plan.
## 7. The one-line summary for each
- **Part A** = inpatient/hospital, usually free, per-stay deductible.
- **Part B** = outpatient/doctor, $185/month in 2026, 20% coinsurance with no cap.
## Which should you take at 65?
Most people should take **both** at 65 unless they have creditable employer coverage. Part A is free and rarely worth delaying. Part B is only worth delaying if you have active employer insurance — and even then, confirm it's creditable in writing before you skip it.
If you're unsure whether your current coverage counts, that's exactly the moment to talk to a licensed advisor or your State Health Insurance Assistance Program (SHIP), which offers free, unbiased help.
*Educational information only, not insurance or medical advice. Premiums, deductibles, and rules are for 2026 and can change — verify current figures at Medicare.gov before making decisions.*
