The Basic Difference: Hospital Insurance vs. Doctor Visits
Part A is hospital insurance. It covers inpatient hospital stays, skilled nursing care after a hospital stay, hospice, and some home health services. Part B is medical insurance. It covers doctor visits, outpatient care, lab tests, imaging, and preventive services like screenings and vaccines.
Most people get Part A automatically when they turn 65 and claim Social Security. Part B is optional, but you pay a monthly premium for it — currently $164.90 per month for most people in 2024, though this amount changes yearly. If you delay Part B without a valid reason, you will pay a permanent penalty of 10 percent for each year you waited.
Together, Part A and Part B are called Original Medicare. They work side by side: Part A pays for the hospital bed, Part B pays for the doctor who treats you in that bed. Neither one covers everything, and both have deductibles and copays you pay out of pocket.
Key Takeaways
- Part A covers hospital stays and skilled nursing care; Part B covers doctor visits and outpatient services — you need both for full coverage.
- Part A has no monthly premium for most people, but Part B costs a monthly fee that increases if you delay signing up without a valid reason.
- Part A has a deductible of $1,632 per hospital stay in 2024; Part B has a $240 annual deductible plus 20 percent coinsurance on most services.
- If you work past 65 and have employer health insurance, you may be able to delay Part B without penalty, but you must report this to Medicare.
Part A: What It Covers and What You Pay
Part A covers a hospital bed for up to 60 days per benefit period. A benefit period starts the day you enter the hospital and ends 60 days after you leave without receiving inpatient care. If you go back to the hospital after that 60-day window, a new benefit period begins and you pay a new deductible.
Part A also covers skilled nursing facilities — not regular nursing homes, but facilities where you receive skilled care (like physical therapy or wound care) after a hospital stay of at least three days. It covers up to 100 days per benefit period, though you pay a copay of $204.75 per day for days 21 through 100 in 2024. Hospice care and some home health services are covered too, as long as a doctor orders them.
The Part A deductible in 2024 is $1,632 per benefit period. You pay this once per hospital stay, no matter how long you stay. After you meet the deductible, Part A covers all approved hospital costs for the first 60 days. Days 61 through 90 cost you $408 per day. If you stay longer than 90 days, you have 60 "lifetime reserve days" you can use, at a cost of $816 per day.
Most people pay no monthly premium for Part A because they or their spouse paid Medicare taxes while working. If you did not work long enough to may have access to, you can buy Part A, but the premium is $278 or $505 per month depending on your work history.
Part B: What It Covers and What You Pay
Part B covers doctor visits — both in the office and in the hospital as an outpatient. It covers lab tests, X-rays, CT scans, ultrasounds, and other imaging. It covers physical therapy, occupational therapy, and speech therapy when a doctor orders them. It covers preventive services with no copay: annual wellness visits, cancer screenings, bone density tests, diabetes screenings, and vaccines like flu and pneumonia shots.
Part B also covers durable medical equipment — wheelchairs, walkers, oxygen tanks, diabetic supplies — when a doctor prescribes them. It covers ambulance services and emergency room visits. It does not cover routine dental care, vision exams, hearing aids, or most prescription drugs (those are covered under Part D, a separate plan).
The Part B deductible in 2024 is $240 per year. After you meet it, you pay 20 percent of the approved amount for most services. For example, if a doctor visit is approved at $100, Medicare pays $80 and you pay $20. For hospital outpatient services like emergency room visits or imaging, you may pay a copay instead of coinsurance — the amount varies by service.
The standard Part B premium in 2024 is $164.90 per month, but you may pay more if your income is above a certain threshold. In 2024, if your modified adjusted gross income is over $97,000 (or $194,000 if married), you pay an extra amount called an Income-Related Monthly Adjustment Amount, or IRMAA. This surcharge can range from $66 to $560 per month depending on your income.
How Part A and Part B Work Together
When you are admitted to the hospital, Part A pays for the bed and hospital services. Part B pays for the doctor who treats you. If you need an X-ray in the hospital, Part A covers the facility cost and Part B covers the radiologist's fee. Both deductibles explore separately — you pay the Part A deductible for the hospital stay and the Part B deductible for the year (if you have not met it yet).
If you receive outpatient care — say, a doctor visit in an office or an imaging test at an imaging center — Part B covers it. Part A does not. This is why you need both: Part A alone would leave you paying for every doctor visit and test outside a hospital.
Original Medicare (Part A and Part B together) covers about 80 percent of approved healthcare costs on average. The other 20 percent — copays, coinsurance, and services not covered — comes out of your pocket. Many people buy a Medigap policy (supplemental insurance) or a Medicare Advantage plan (Part C) to cover some of these gaps, but that is a separate choice from Part A and Part B.
When You Can Enroll and What Happens If You Miss the important date
You become may be able to access for Medicare the month you turn 65. Your initial enrollment period is seven months long: three months before the month you turn 65, the month you turn 65, and three months after. If you sign up during this window, your coverage starts the month you turn 65 (or the month after, depending on when you sign up).
Part A enrollment is usually automatic if you are already receiving Social Security. If you are not, you must sign up yourself through Medicare.gov, by phone at 1-800-MEDICARE, or at your local Social Security office.
Part B enrollment is not automatic. You must choose to sign up. If you do not sign up during your initial enrollment period and you do not have a valid reason for the delay — such as active employer health insurance — you will pay a permanent 10 percent penalty on your Part B premium for as long as you have Medicare. This penalty is added to your monthly bill and never goes away.
If you are still working at 65 and covered by your employer's health plan, you may be able to delay Part B without penalty. You must sign up within eight months of losing that coverage, and you must tell Medicare you had employer coverage. Get a written statement from your employer's benefits office confirming your coverage dates, because Medicare will ask for proof.
Part A and Part B Costs at a Glance
| Part A | Part B | |
|---|---|---|
| Monthly Premium | $0 for most people | $164.90 (2024 standard) |
| Annual Deductible | $1,632 per hospital stay | $240 per year |
| Coinsurance After Deductible | $0 for days 1–60; $408/day for days 61–90 | 20% of approved amount |
| What It Covers | Hospital stays, skilled nursing, hospice, some home health | Doctor visits, outpatient care, tests, preventive services |
What Part A and Part B Do Not Cover
Neither Part A nor Part B covers prescription drugs. That is Part D, a separate plan you buy from a private insurance company. You can enroll in Part D during your initial Medicare enrollment period or during the annual open enrollment period in the fall.
Neither covers dental care, routine eye exams, eyeglasses, or hearing aids. Some Medicare Advantage plans (Part C) include dental and vision benefits, but Original Medicare does not.
Part A does not cover custodial care in a nursing home — help with bathing, dressing, and eating — unless it is part of skilled nursing care after a hospital stay. Part B does not cover routine foot care, most acupuncture, or weight loss programs, though there are exceptions for specific conditions.
Both have limits on how much they will pay for certain services. For example, Part B covers up to 60 days of inpatient psychiatric care per year. If you need more, you pay out of pocket or use supplemental insurance.
Frequently Asked Questions
Do I have to take Part B when I turn 65?
No, Part B is optional. But if you do not sign up during your initial enrollment period and you do not have employer coverage or another valid reason for the delay, you will pay a 10 percent penalty on your Part B premium for life. If you are still working and covered by your employer's health plan, you can delay Part B without penalty.
What if I have Part A but not Part B?
You will be covered for hospital stays but not for doctor visits or outpatient care. This leaves you paying out of pocket for most medical services outside a hospital. Most people need both parts to have reasonable coverage.
Can I switch from Original Medicare to Medicare Advantage?
Yes. Medicare Advantage (Part C) is an alternative to Original Medicare. It includes Part A and Part B coverage through a private insurance company, usually with lower out-of-pocket costs but a narrower network of doctors. You can switch during the annual open enrollment period or during the Medicare Advantage open enrollment period in the winter.
What happens to my Part A and Part B if I move to another state?
Your Part A and Part B coverage follows you anywhere in the United States. There is no state-specific enrollment or approval. However, if you are in a Medicare Advantage plan, you may need to switch plans if your current plan does not serve your new state.
Do I pay taxes on my Medicare benefits?
No. Your Part A and Part B benefits are not taxable income. However, if your total income is above a certain threshold, you may pay higher premiums for Part B and Part D through the IRMAA surcharge.