Medicare words in plain English
Short meanings for the terms you will see in plan letters, booklets and our guides.
Jump to a letter: A C D E F H I L M N O P S
- Annual Enrollment Period
- October 15 to December 7 each year. You can join, switch or drop a Medicare Advantage or drug plan. Changes start January 1.
- Annual Notice of Change (ANOC)
- The letter your plan sends by September 30 listing what changes on January 1.
- C-SNP
- A Special Needs Plan for people with certain chronic conditions, such as diabetes or heart failure.
- Coinsurance
- A percentage of the cost you pay, such as 20%.
- Copay
- A set dollar amount you pay for a visit or a drug, such as $20.
- Creditable coverage
- Drug coverage at least as good as Medicare’s. Having it lets you delay Part D without a penalty.
- D-SNP
- A Special Needs Plan for people who have both Medicare and Medicaid.
- Deductible
- What you pay for care or drugs before the plan starts paying its share.
- Evidence of Coverage
- The full rulebook for your plan: what is covered, what you pay, and how to appeal.
- Extra Help
- A federal program that lowers drug costs for people with limited income and savings.
- Formulary
- The list of drugs a plan covers, grouped into tiers that set what you pay.
- HMO
- A plan type that usually requires you to use its network and get referrals to see specialists.
- Initial Enrollment Period
- The 7 months around your 65th birthday month when you can first sign up for Medicare.
- IRMAA
- An extra amount added to Part B and Part D premiums for people with higher income.
- Late enrollment penalty
- An amount added to your premium if you sign up for Part B or Part D later than allowed without other qualifying coverage.
- Maximum out-of-pocket
- The most you pay in a year for covered in-network care in a Medicare Advantage plan. Original Medicare has no such limit.
- Medicare Advantage (Part C)
- A plan from a private company that covers Part A and Part B, and often drugs and extras such as dental.
- Medicare Advantage Open Enrollment
- January 1 to March 31. If you are in a Medicare Advantage plan, you can make one change: another Medicare Advantage plan, or Original Medicare with a drug plan.
- Medicare Savings Programs
- State programs that can pay Medicare premiums and, for some people, other costs.
- Medicare Supplement (Medigap)
- Private insurance that helps pay costs Original Medicare does not, such as coinsurance. It does not work with Medicare Advantage.
- Network
- The doctors, hospitals and pharmacies a plan works with. Going outside it can cost more or not be covered.
- Original Medicare
- Part A (hospital) and Part B (medical) from the federal government. You can see any doctor who accepts Medicare.
- Part A
- Hospital insurance: inpatient stays, skilled nursing facility care, hospice and some home health care.
- Part B
- Medical insurance: doctor visits, outpatient care, tests, and medical equipment.
- Part D
- Prescription drug coverage, either in a Medicare Advantage plan or a separate drug plan.
- PPO
- A plan type that lets you see doctors outside the network, usually for a higher cost.
- Premium
- What you pay each month to have the coverage, whether or not you use it.
- Prior authorization
- Approval you or your doctor must get from the plan before some services or drugs are covered.
- Special Enrollment Period
- A window outside the usual dates, opened by a life event such as moving, losing other coverage, or your plan ending.
- Summary of Benefits
- A short overview of a plan’s costs and benefits, used to compare plans.
For every plan in your area, including plans we do not offer, visit Medicare.gov or call 1-800-MEDICARE (1-800-633-4227, TTY 1-877-486-2048).