Medicare Glossary

Oct 15–Dec 7 each year, when anyone on Medicare can change plans for January 1.

During AEP you can switch Medicare Advantage plans, move between Advantage and Original Medicare, or change Part D drug plans. Formularies, premiums, and networks change yearly, so it’s the time for a free plan review.

Learn more: Medicare Open Enrollment · Related: Medicare Advantage Open Enrollment

Other drug or health coverage at least as good as Medicare’s — it protects you from late penalties.

If you keep creditable coverage (like an active employer plan) past 65, you can delay Medicare without a penalty and get a Special Enrollment Period later. Keep the notice your plan sends proving it’s creditable.

Learn more: Special Enrollment Period · Related: Special Enrollment Period, Late Enrollment Penalty

A yearly Jan 1–Mar 31 window to sign up for Part B if you missed your first chance.

If you didn’t enroll in Part B when first eligible and don’t qualify for a Special Enrollment Period, you use the GEP. A late-enrollment penalty usually applies for as long as you have Part B.

Learn more: General Enrollment Period · Related: Initial Enrollment Period, Special Enrollment Period, Late Enrollment Penalty

Times when a Medigap insurer must sell you a policy without health questions.

During your Medigap Open Enrollment (the 6 months after your Part B starts at 65) and certain guaranteed-issue situations, insurers can’t deny you or charge more for health reasons. Outside those windows, Utah generally allows medical underwriting.

Learn more: Medigap · Related: Medigap, Initial Enrollment Period

Your first chance to sign up for Medicare — a 7-month window around your 65th birthday.

The IEP runs from 3 months before the month you turn 65, through your birthday month, to 3 months after. Signing up in the first 3 months gets coverage started the fastest. Missing it can trigger permanent late penalties.

Learn more: Medicare enrollment periods · calculator · Related: General Enrollment Period, Special Enrollment Period, Late Enrollment Penalty

A permanent surcharge for signing up for Part B or Part D too late.

Part B adds 10% to your premium for each full 12 months you could have had it but didn’t; Part D adds about 1% of the national base premium per uncovered month. Both usually last as long as you have the coverage.

Learn more: Part B penalty calculator · Related: General Enrollment Period, Creditable Coverage

Jan 1–Mar 31, when Advantage members can make one change.

If you’re already in a Medicare Advantage plan, the OEP lets you switch to a different Advantage plan or drop back to Original Medicare with a Part D plan — one change per year.

Learn more: Open Enrollment · Related: Annual Enrollment Period

A penalty-free window to enroll or change plans after a qualifying life event.

Events like losing employer coverage, moving out of a plan’s area, or qualifying for Extra Help open a SEP. It lets you enroll outside the normal windows without a late penalty.

Learn more: Special Enrollment Period · Related: Initial Enrollment Period, General Enrollment Period, Creditable Coverage

Your share of a cost as a percentage — often 20% under Original Medicare Part B.

After you meet the deductible, Original Medicare typically pays 80% of the approved amount for Part B services and you pay the remaining 20% — with no cap, which is why many people add Medigap or Medicare Advantage.

Learn more: Medicare costs · Related: Copayment, Deductible, Out-of-Pocket Maximum

A flat dollar amount you pay for a service or prescription (e.g. $20 for a visit).

Copays are common in Medicare Advantage and Part D plans — a set amount per office visit, specialist, or drug tier — instead of a percentage. Predictable, but they add up with frequent care.

Learn more: Medicare costs · Related: Coinsurance, Deductible

A former Part D phase of higher drug costs — replaced in 2026 by a $2,000 out-of-pocket cap.

The old “donut hole” is gone. Now once your out-of-pocket drug spending reaches the annual cap ($2,000 in 2026), you pay nothing more for covered drugs the rest of the year.

Learn more: Part D plans · Related: Medicare Part D, Formulary

What you pay out of pocket before your coverage starts paying.

Medicare has separate deductibles — a Part A hospital deductible per benefit period and a smaller annual Part B deductible. Part D and Advantage plans may have their own drug deductibles.

Learn more: Medicare costs · Related: Coinsurance, Copayment, Premium

An income-based surcharge added to Part B and Part D premiums for higher earners.

The Income-Related Monthly Adjustment Amount uses your income (MAGI) from two years ago. Above the year’s threshold, you pay extra on both Part B and Part D. A life-changing event lets you appeal with Form SSA-44.

Learn more: IRMAA explained · calculator · Related: MAGI, Premium

Modified Adjusted Gross Income — the income figure that decides your IRMAA.

MAGI is your adjusted gross income plus tax-exempt interest. Social Security uses your MAGI from two years prior to set any IRMAA surcharge, which is why a one-time income spike can raise your premiums later.

Learn more: IRMAA · Related: IRMAA

A yearly cap on what you pay for covered care — Medicare Advantage has one; Original Medicare does not.

Every Medicare Advantage plan caps your in-network out-of-pocket spending for the year. Original Medicare alone has no cap, which is why people add Medigap or choose Advantage for protection.

Learn more: Out-of-pocket maximum · Related: Coinsurance, Medicare Part C

The monthly amount you pay to have a coverage — whether or not you use it.

Most people pay no Part A premium; Part B has a standard monthly premium (higher earners pay more via IRMAA). Part D, Medigap, and Medicare Advantage may have their own premiums on top.

Learn more: Medicare costs · Related: Deductible, IRMAA

A Medicare Advantage plan that uses an in-network-only model, often with referrals.

HMO Advantage plans usually require you to use in-network providers and get referrals to see specialists — lower cost in exchange for less flexibility. Out-of-network care is generally only covered for emergencies.

Learn more: HMO vs PPO · Related: PPO, Medicare Part C, Network

Hospital insurance — inpatient stays, skilled nursing, hospice. Usually premium-free.

Part A covers inpatient hospital care, skilled nursing facility care after a qualifying stay, hospice, and some home health. Most people pay no premium because they or a spouse paid Medicare taxes for 10+ years.

Learn more: Part A vs Part B · Related: Medicare Part B, Original Medicare, Skilled Nursing Facility (SNF) Care

Medical insurance — doctor visits, outpatient care, preventive services. Has a monthly premium.

Part B covers doctors, outpatient care, durable medical equipment, and preventive services. It has a standard monthly premium (higher with IRMAA) and an annual deductible, then usually 20% coinsurance.

Learn more: Part A vs Part B · Related: Medicare Part A, Premium, IRMAA

An all-in-one private plan that replaces Original Medicare, often with extras and a $0 premium.

Advantage plans bundle Part A, B, and usually D, plus extras like dental and vision, and cap your yearly out-of-pocket. The trade-off is provider networks and possible referrals. Availability and networks matter locally.

Learn more: Medicare Advantage · Related: HMO, PPO, Out-of-Pocket Maximum, Medigap

Prescription drug coverage — a standalone plan or built into a Medicare Advantage plan.

Part D covers prescriptions through a plan’s formulary and pharmacy network. Costs vary a lot by plan and pharmacy; in 2026 out-of-pocket drug spending is capped at $2,000.

Learn more: Part D plans · Related: Formulary, Drug Tier, Coverage Gap

A policy that pairs with Original Medicare to pay its out-of-pocket gaps.

Medigap covers cost-sharing like coinsurance and deductibles, so you can see any Medicare provider nationwide with predictable costs and no networks. You add a separate Part D plan. Plan G and Plan N are the most popular.

Learn more: Medigap · Related: Plan G, Plan N, Guaranteed Issue, Medicare Part C

The federal program — Part A (hospital) and Part B (medical) — you get directly from Medicare.

With Original Medicare you can see any provider nationwide that accepts Medicare, with no networks. It has no drug coverage and no out-of-pocket cap, so most people add Part D and either Medigap or choose Medicare Advantage instead.

Learn more: Part A vs Part B · Related: Medicare Part A, Medicare Part B, Medigap, Medicare Part C

The most comprehensive Medigap plan for new enrollees — covers nearly everything but the Part B deductible.

After you pay the annual Part B deductible, Plan G covers your Medicare cost-sharing at 100%. A High-Deductible version trades a much lower premium for a high annual deductible.

Learn more: Plan G vs Plan N · Related: Plan N, Medigap

A lower-premium Medigap plan with small copays at visits and the ER.

Plan N covers most Medigap gaps for a lower premium than Plan G, in exchange for small office and ER copays and not covering Part B excess charges.

Learn more: Plan G vs Plan N · Related: Plan G, Medigap, Part B Excess Charges

A Medicare Advantage plan that lets you go out-of-network at higher cost.

PPO Advantage plans don’t usually require referrals and cover out-of-network care at a higher share of cost — more flexibility than an HMO, often for a higher premium.

Learn more: HMO vs PPO · Related: HMO, Medicare Part C, Network

A Medicare Advantage plan tailored to a specific group — like people with both Medicare and Medicaid.

SNPs limit membership to people who share a condition or situation. The most common locally is the D-SNP, for people who are dual-eligible (Medicare + Medicaid), with benefits coordinated for that group.

Learn more: D-SNP plans · Related: D-SNP, Dual Eligible

A Medicare Advantage plan built for people who have both Medicare and Medicaid.

A D-SNP coordinates Medicare and Medicaid benefits in one plan, often with extra benefits like transportation, OTC allowances, and dental, at little or no cost to dual-eligible members.

Learn more: D-SNP plans · Related: Dual Eligible, Special Needs Plan, Medicaid

Having both Medicare and Medicaid — which together cover most of your costs.

If you qualify for both programs, Medicaid can pay Medicare premiums and cost-sharing, you usually get Extra Help automatically, and a D-SNP can coordinate everything in one plan.

Learn more: Dual-eligible · Related: D-SNP, Medicaid, Extra Help, Medicare Savings Programs

A federal program that lowers or eliminates Part D premiums, deductibles, and drug copays.

Extra Help (the Part D Low-Income Subsidy) can dramatically cut what you pay for prescriptions. Many who qualify never apply; if you have Medicaid, SSI, or a Medicare Savings Program you may qualify automatically.

Learn more: Extra Help · Related: Medicare Savings Programs, Dual Eligible, Medicare Part D

A joint state-federal program that helps with health costs for people with limited income.

In Utah, Medicaid can work alongside Medicare — paying premiums and cost-sharing for dual-eligible beneficiaries and opening the door to D-SNP plans and Extra Help.

Learn more: Medicare & Medicaid in Utah · Related: Dual Eligible, D-SNP

State programs that pay your Part B premium — and can unlock Extra Help automatically.

MSPs (QMB, SLMB, QI) help with Medicare costs based on income and resources. Qualifying for one also enrolls you in Extra Help for drug costs. Limits are higher than many people expect.

Learn more: Medicare Savings Programs · Related: QMB, SLMB, QI, Extra Help

A Medicare Savings Program that pays the Part B premium for a slightly higher income range.

QI pays your Part B premium and unlocks Extra Help, with the highest income limit of the three main MSPs. It’s first-come, first-served each year and you must re-apply.

Learn more: Medicare Savings Programs · Related: Medicare Savings Programs, QMB, SLMB

The most generous Medicare Savings Program — pays Part A/B premiums, deductibles, and coinsurance.

QMB has the lowest income limit of the MSPs and the biggest benefit: it covers your Part B premium and most Medicare cost-sharing, and providers can’t bill you for covered services.

Learn more: Medicare Savings Programs · Related: Medicare Savings Programs, SLMB, QI

A Medicare Savings Program that pays your Part B premium (higher income limit than QMB).

SLMB pays the Part B premium for people slightly above the QMB income limit, and qualifies you for Extra Help. It doesn’t cover other cost-sharing the way QMB does.

Learn more: Medicare Savings Programs · Related: Medicare Savings Programs, QMB, QI

When a provider agrees to accept Medicare’s approved amount as full payment.

Providers who “accept assignment” bill Medicare directly and can’t charge you more than the Medicare-approved amount (beyond your deductible/coinsurance). Most providers accept assignment.

Learn more: Part A vs Part B · Related: Part B Excess Charges, Coinsurance

A level within a formulary that sets your copay — lower tiers cost less.

Formularies group drugs into tiers, from Tier 1 (generics, cheapest) to specialty tiers (most expensive). A drug on Tier 2 in one plan might be Tier 4 in another, with a very different copay.

Learn more: Tier 3 vs Tier 4 · Related: Formulary, Medicare Part D

A plan’s list of covered drugs, organized into cost tiers.

Every Part D and Advantage drug plan has its own formulary. The same drug can sit on different tiers (and cost very different amounts) from plan to plan, so matching the formulary to your medications is key.

Learn more: Part D plans · Related: Drug Tier, Medicare Part D, Prior Authorization

The doctors, hospitals, and pharmacies a plan contracts with for the best cost.

Medicare Advantage plans use networks (HMO or PPO); Original Medicare + Medigap has no network — any Medicare provider works. In rural areas, verifying your providers are in-network matters a lot.

Learn more: HMO vs PPO · Related: HMO, PPO, Medicare Part C

An extra amount (up to 15%) a non-participating provider can bill above Medicare’s rate.

A provider who doesn’t accept assignment can charge up to 15% over the Medicare-approved amount. Medigap Plan G covers these excess charges; Plan N does not.

Learn more: Plan G vs Plan N · Related: Assignment, Plan G, Plan N

A plan’s requirement to approve a drug or service before it’s covered.

Some drugs and services need the plan’s OK first. It’s common in Medicare Advantage and for higher-tier drugs. Your doctor submits the request; if denied, you can appeal.

Learn more: Medicare Advantage · Related: Step Therapy, Formulary

Short-term rehab or nursing care Part A covers after a qualifying hospital stay.

Medicare Part A can cover skilled nursing care after a qualifying inpatient hospital stay — fully for the first 20 days, then with daily coinsurance. It’s short-term recovery care, not long-term custodial care.

Learn more: Part A vs Part B · Related: Medicare Part A, Coinsurance

A rule requiring you to try a lower-cost drug before the plan covers a pricier one.

Under step therapy, the plan asks you to “step through” a preferred, usually cheaper drug first. If it doesn’t work or isn’t appropriate, your doctor can request an exception for the drug you need.

Learn more: Part D plans · Related: Prior Authorization, Formulary