What Is Medicare Part A Supplement?
Medicare Part A supplement, commonly called a Medigap policy, is private insurance that fills the gaps left by Original Medicare’s hospital coverage. While Part A pays for inpatient stays, skilled nursing facility care, hospice, and some home health services, it does not cover all costs. A supplement pays the coinsurance, copayments, and deductibles that you would otherwise owe out of pocket.
Core Benefits Covered by Part A Supplements
All standardized Medigap plans (Plans A through N) must include the following Part A‑related benefits:
- Hospital coinsurance for days 61‑90 and lifetime reserve days.
- Skilled nursing facility coinsurance for days 21‑100.
- Hospice care coinsurance or copayment.
- First three pints of blood needed during a covered stay.
Plans C, D, F, G, M, and N also cover the Part A deductible, which in 2024 is $1,632 per benefit period. Plans K and L cover a percentage of that deductible, while Plans A and B do not.
How Pricing Works: Premiums, Deductibles, and Out‑of‑Pocket Limits
Premiums for a Part A supplement vary by plan letter, insurer, geographic area, and age rating method. The three common rating methods are:
- Community‑rated – same premium for all ages.
- Issue‑age rated – premium based on age at purchase; does not increase with age.
- Attained‑age rated – premium rises as you get older.
In 2024 the national average monthly premium for Plan G (the most popular comprehensive option) is about $150, but rates can range from $90 in low‑cost states to over $250 in high‑cost areas. Unlike Medicare Advantage, Medigap policies have no annual out‑of‑pocket maximum; they simply pay the cost‑sharing amounts defined by the plan.
Buyer Checklist: Choosing the Right Plan
Use the following criteria to compare policies side by side:
- Coverage completeness – Do you need the Part A deductible covered? Plans G and N include it; Plan N adds a small copayment for office visits.
- Premium stability – Community‑rated plans protect against future price spikes.
- Insurer financial strength – Check A.M. Best or Standard & Poor’s ratings; a solvent carrier guarantees claim payment.
- Enrollment window – The six‑month Medigap Open Enrollment Period starts the month you turn 65 and are enrolled in Part B. Guaranteed issue rights apply only during this window.
- State‑specific protections – Some states offer additional guaranteed‑issue periods or community‑rating rules.
Cost‑vs‑Value Analysis: When a Supplement Makes Sense
Calculate your expected annual hospital utilization. If you anticipate two or more inpatient stays per year, the Part A deductible and daily coinsurance can exceed $3,000. A Plan G premium of $