Advance Beneficiary Notice (ABN)
A notice a provider gives you if they think Medicare may not cover a service.
Annual Enrollment Period (AEP)
The time each year (October 15–December 7) when you can join, switch, or drop a Medicare plan.
Appeal
The process to ask Medicare to review and change a coverage or payment decision.
Assignment
When a doctor or provider agrees to accept the Medicare-approved amount as full payment.
Benefit Period
The way Medicare measures your use of hospital and skilled nursing facility services.
Catastrophic Coverage
The stage in a Part D plan where your out-of-pocket costs are significantly reduced after reaching a spending threshold.
Chronic Care Management (CCM)
Services provided to help manage chronic conditions like diabetes or heart disease.
Coinsurance
Your share (usually a percentage) of the costs of a covered service.
Copayment
A fixed amount you pay for a covered service.
Coverage Gap (Donut Hole)
A temporary limit on what the drug plan will cover for drugs.
Deductible
The amount you must pay before Medicare begins to pay.
Dual Eligible
Someone who qualifies for both Medicare and Medicaid.
Durable Medical Equipment (DME)
Equipment like wheelchairs or oxygen supplies that Medicare may cover.
Excess Charges
The amount a doctor can charge above the Medicare-approved amount if they don’t accept assignment.
Extra Help
A program to help people with limited income pay for Medicare drug costs.
Formulary
A list of prescription drugs covered by a Medicare drug plan.
Formulary Tier
A category of drugs in a Part D plan that determines your cost-sharing.
Guaranteed Issue Rights
Rights you have in certain situations to buy a Medigap policy.
Hospice Care
End-of-life care covered under Medicare Part A.
Income-Related Monthly Adjustment Amount (IRMAA)
An extra charge added to your Part B and/or Part D premium if your income is above a certain level.
Initial Enrollment Period (IEP)
The 7-month period when you first become eligible for Medicare.
Lifetime Reserve Days
Extra days Medicare will pay for when you're in a hospital for more than 90 days.
Low-Income Subsidy (LIS)
Also known as "Extra Help," this assists in paying for Medicare prescription drug costs.
Medicare Advantage (Part C)
A type of Medicare plan offered by private companies that includes Part A, Part B, and usually Part D.
Medigap (Medicare Supplement Insurance)
Private insurance that helps pay some of the costs not covered by Original Medicare.
Network
A group of doctors, hospitals, and other providers that a plan has contracted with.
Observation Status
A hospital classification that may affect whether Medicare covers your stay.
Out-of-Pocket Maximum
The most you’ll pay in a year for covered services in a Medicare Advantage plan.
Part A
Hospital insurance.
Part B
Medical insurance.
Part C
Medicare Advantage.
Part D
Prescription drug coverage.
Premium
The amount you pay for your Medicare coverage.
Prior Authorization
Approval you must get from a Medicare plan before it will cover a service.
Referral
A written order from your primary care doctor for you to see a specialist.
Skilled Nursing Facility (SNF)
A facility that provides medically necessary services from nurses or therapists.
Special Enrollment Period (SEP)
Times outside the usual enrollment periods when you can sign up for Medicare.
Telehealth
Remote services provided via phone or video, increasingly covered under Medicare.
This glossary offers a quick reference to key Medicare terms, helping you better understand your coverage and options.