Glossary
Medicare Part A
The hospital insurance side of Original Medicare — covers inpatient stays, skilled nursing, hospice, and some home health.
Also known as: Hospital Insurance, Part A
Quick answer
Medicare Part A is the hospital insurance component of Original Medicare. It pays for inpatient hospital stays, skilled nursing facility care after a qualifying hospital stay, hospice care, and limited home health care. Most people get Part A premium-free because they (or a spouse) paid Medicare taxes for at least 40 quarters (about 10 years) of work.
Why it matters
Part A is the foundation of your Medicare coverage at 65. For retired military, Part A is also a prerequisite for keeping TRICARE benefits — you cannot have TRICARE For Life without Part A and Part B.
When you'll encounter it
You become eligible the first day of the month you turn 65. If you're already collecting Social Security, you're enrolled automatically. Otherwise you actively enroll through SSA during your Initial Enrollment Period (the 7-month window around your 65th birthday).
Impact on Medicare
Part A pays first for covered inpatient services. In 2026 it has a per-benefit-period deductible and daily coinsurance after day 60 of a hospital stay. There is no monthly premium for most people.
Impact on TRICARE For Life
TRICARE For Life acts as the secondary payer behind Part A. TFL typically picks up the Part A deductible and coinsurance for services that are also TRICARE-covered, so most beneficiaries owe $0 out-of-pocket on covered inpatient care.
Impact on Medicare Advantage
If you enroll in a Medicare Advantage plan, the plan administers your Part A benefits using its own copays and network rules instead of Original Medicare's cost shares.
VA Healthcare considerations
Part A does not interact with VA hospital care — VA facilities are funded directly by the Department of Veterans Affairs, not billed to Medicare. Having Part A does not affect your VA priority group, and using VA care does not consume any Medicare benefit. Many retirees use Medicare/TFL for civilian hospitals and VA for service-connected conditions.
Military-specific context
If you are still working past 65 with employer coverage, you can usually delay Part B without penalty — but you should still enroll in premium-free Part A unless you contribute to an HSA. Most military retirees on a pension (not active employer coverage) have no reason to delay either part.
Common misconceptions
- "Part A is automatic for everyone at 65." — Only automatic if you're already receiving Social Security or RRB benefits. Otherwise you must actively enroll.
- "Part A covers long-term custodial nursing home care." — It does not. Part A only covers short-term skilled care after a qualifying hospital stay, up to 100 days per benefit period.
Common mistakes to avoid
- Declining Part A when you have a Health Savings Account but no longer contributing — there is no benefit to declining at that point.
- Assuming Part A covers a stay in a nursing home for memory care or assisted living. It does not — that is custodial care.
- Forgetting to verify your Part A effective date in milConnect after Social Security confirms enrollment.
Real-world scenario: A 65-year-old retired Army sergeant is hospitalized for 5 days after a fall.
Medicare Part A covers the inpatient stay after the Part A deductible. TRICARE For Life pays the Part A deductible as the secondary payer, leaving him with $0 out-of-pocket on the hospital bill.
Questions people commonly ask
- Is Medicare Part A really free?
- Do I have to enroll in Part A if I'm still working at 65?
- Does Part A cover long-term nursing home care?
- What happens to my TRICARE if I have Part A but not Part B?
Continue learning
— suggested by the knowledge graph- Appointment of RepresentativeA signed form (CMS-1696) that authorizes another person — family member, attorney, or advocate — to file or pursue a Medicare appeal on your behalf.
- Creditable CoverageNon-Medicare coverage that CMS deems at least as good as a standard Medicare Part D plan — TRICARE Pharmacy qualifies, so TFL beneficiaries don't need Part D.
- Creditable Drug CoveragePrescription drug coverage that CMS certifies is at least as good as standard Medicare Part D — including TRICARE Pharmacy and VA Pharmacy.
- Disability Medicare Eligibility (Under 65)Medicare eligibility before age 65 — automatic after 24 months of SSDI, immediately for ALS, and based on dialysis/transplant for ESRD.
- Durable Medical Equipment (DME)Medically necessary, reusable equipment for home use — covered by Part B at 80% after the deductible.
- End-Stage Renal Disease (ESRD)A condition (permanent kidney failure requiring dialysis or transplant) that grants Medicare eligibility at any age.
- General Enrollment Period (GEP)The January 1 – March 31 window each year when you can sign up for Medicare if you missed your IEP and don't qualify for an SEP.
- Do I need Medicare Part A if I have TRICARE?Yes. TFL requires Part A and Part B. Part A is typically premium-free if you or your spouse worked 40+ quarters paying Medicare taxes.
- Can I take Part A now and add Part B later?You can — but for TFL purposes, that's the same as not enrolling. TFL requires both A and B simultaneously. Without B, TFL is suspended.
- I'm turning 65. What should I do first?About 3 months before your 65th birthday, sign up for Medicare Parts A and B at SSA.gov. TRICARE For Life activates automatically once both are effective and DEERS is current.
- I'm still working past 65. Can I delay Part B?Only if you have true employer group health coverage from active employment (yours or your spouse's, 20+ employees). In that case you get a Special Enrollment Period later. But TFL won't activate until you take Part B.
- What is the Initial Enrollment Period (IEP)?The 7-month window around your 65th birthday — 3 months before, your birthday month, and 3 months after — when you first enroll in Medicare without penalty.
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Continue learning straight from the source. Every link below goes to an official government or DoD resource.
Last reviewed January 2026 against the 2026 Medicare & You and TRICARE For Life handbooks.