Medicare Glossary

Secondary Payer

An insurer, including Medicare, that pays after the primary insurer has paid its share of a claim. Whether Medicare is the primary or secondary payer depends on the type of other coverage you have, such as employer or veterans coverage.

Service Area

The geographic area where a Medicare Advantage or Part D plan is available and provides coverage. Plans may have different networks and costs in different parts of their service area. Moving outside a plan's service area may trigger a Special Enrollment Period.

Skilled Nursing Facility (SNF)

A facility that provides short-term skilled care and therapy after a qualifying 3-day inpatient hospital stay. Medicare Part A covers SNF care for up to 100 days per benefit period, with no copay for days 1–20 and a daily coinsurance for days 21–100.

Also known as: SNF, Nursing home (short-term)

Special Enrollment Period (SEP)

A window outside the standard enrollment periods during which you can join, switch, or drop a Medicare plan. SEPs are triggered by qualifying life events such as losing employer coverage, moving, gaining Medicaid eligibility, or your plan leaving the area.

Also known as: SEP

Special Needs Plan (SNP)

A Medicare Advantage plan designed for people with specific diseases, conditions, or characteristics — such as dual eligibles (Medicare and Medicaid), institutionalized beneficiaries, or those with certain chronic conditions like diabetes or heart disease.

Also known as: SNP

Specified Low-Income Medicare Beneficiary (SLMB)

A Medicare Savings Program that helps pay Part B premiums for people with income modestly above the Qualified Medicare Beneficiary (QMB) limit.

Also known as: SLMB

Standard Benefit Package

The minimum level of coverage that Medicare Part D prescription drug plans must provide. Plans may offer enhanced coverage above this standard, but all must include at least the standard benefit.

Star Ratings

A 1–5 star quality rating system that CMS uses to measure how well Medicare Advantage and Part D plans perform. Ratings are based on measures including member experience, customer service, and managing chronic conditions. Higher-rated plans may receive bonus payments.

Also known as: CMS Star Ratings, Quality ratings

Step Therapy

A coverage requirement where you must try a less expensive drug first before your plan will cover a more expensive one. Commonly used in Medicare Advantage and Part D plans to control costs.

Also known as: Fail first policy

Summary of Benefits

A standardized document that Medicare Advantage and Part D plans must provide that summarizes the plan's costs, covered benefits, and important rules. It is a shorter, easier-to-read version of the Evidence of Coverage.

Supplemental Benefits

Extra benefits offered by Medicare Advantage plans beyond the standard Medicare coverage. Examples include dental, vision, hearing, fitness programs, over-the-counter allowances, and transportation to medical appointments.

Also known as: Extra benefits