Plain-English definitions of the Medicare, ACA health, and life insurance terms most consumers ask about. Each definition is reviewed by a licensed insurance professional. Cross-linked from across our editorial content so you can read in context.
Missouri's annual guaranteed-issue Medigap switching window tied to policy anniversary.
October 15 – December 7 each year — change Medicare Advantage and Part D plans for next year.
Annual guaranteed-issue Medigap switching window in 10 states — change to equal-or-lesser plan without underwriting.
Drug coverage that's at least as good as standard Part D — keeps you penalty-free if you delay Part D.
Federal program that pays Part D premiums and copays for low-income beneficiaries.
Federal protection requiring carriers to sell you a Medigap plan regardless of health.
Plan G coverage after a federal annual deductible (~$2,870 in 2026); cheapest Medigap monthly premium.
7-month window around your 65th birthday to enroll in Medicare without penalty.
Income-Related Monthly Adjustment Amount — surcharge on Part B and Part D premiums for higher-income enrollees.
Social Security form to request a reduction of IRMAA after a life-changing event.
Carrier review of your health to decide whether to issue Medigap and at what rate — applies outside guaranteed-issue periods.
Part C — private HMO/PPO plans that replace Original Medicare, often with $0 premium.
Jan 1 – Mar 31 — current MA enrollees can change MA plans or drop MA back to Original Medicare.
State Medicaid program that pays Part B premiums for low-income Medicare enrollees.
Private insurance that pays the deductibles, copays, and coinsurance Original Medicare leaves you with.
One-time 6-month window when you can buy any Medigap plan with no medical underwriting.
Annual cap on what you pay for Medicare-covered services in a Medicare Advantage plan ($9,350 in-network for 2026).
Hospital insurance — premium-free for most after 10 years of Medicare-taxed work.
Medical insurance for outpatient/doctor services — standard premium $185/mo in 2026.
Up to 15% above Medicare-approved amounts — only allowed in some states; covered by Plan G but not Plan N.
Standalone prescription drug coverage; required to avoid permanent late enrollment penalty.
Most comprehensive Medigap plan, but closed to those new to Medicare after 2020-01-01.
The most comprehensive Medigap plan available to those new to Medicare today.
Medicare Advantage plans tailored to chronic conditions, dual eligibility, or institutional residence.
12-month guaranteed-issue Medigap window if you joined Medicare Advantage at first eligibility.