Medicare Supplement Plan B: What It Covers and What It Costs in 2026

What Medigap Plan B is

Medicare Supplement Insurance, also called Medigap, is private insurance that helps pay the out-of-pocket costs Original Medicare (Part A and Part B) leaves behind. The policies sold in most states are standardized and labeled with letters — A, B, C, D, F, G, K, L, M, and N. Plan B is one of those standardized letters.

Because Plan B is standardized, the benefits are set by federal rules and are identical no matter which insurance company sells it. A Plan B policy from one carrier covers exactly the same services as a Plan B policy from another. What differs between companies is the monthly premium and customer service — not the coverage.

Don't confuse Medigap 'Plan B' with Medicare 'Part B.' Part B is the medical-insurance portion of Original Medicare. Medigap Plan B is a separate, optional private policy you can buy to fill gaps in both Part A and Part B.

What Plan B covers in 2026

Plan B includes the core 'basic benefits' common to most Medigap letters, plus full coverage of the Part A hospital deductible. Here is what it pays:

• Part A hospital coinsurance, plus coverage for up to 365 additional days of hospital care after your Original Medicare benefits are used up — paid at 100%.
• Part A deductible — Plan B pays this in full. In 2026 the Part A inpatient deductible is $1,736 per benefit period (CMS).
• Part B coinsurance or copayment — generally the 20% of the Medicare-approved amount you would otherwise owe for doctor visits and outpatient care, after the Part B deductible is met.
• First 3 pints of blood needed in a medical procedure each year.
• Part A hospice care coinsurance or copayment.

What Plan B leaves you to pay

Plan B is a mid-level policy, so several costs remain your responsibility. Knowing these gaps is the key to deciding whether Plan B fits your needs.

• The Part B deductible — you pay it yourself. In 2026 that deductible is $283 per year (CMS). Plan B does not cover it.
• Skilled nursing facility (SNF) coinsurance — not covered. In 2026 Original Medicare charges $217 per day for SNF days 21 through 100 (CMS), and that cost falls on you with Plan B.
• Part B excess charges — extra amounts a provider may bill when they don't accept Medicare assignment. Plan B does not cover these.
• Foreign travel emergency care — not included in Plan B.
• Prescription drugs — no Medigap policy covers them. For drug coverage you generally need a separate Part D plan.

How Plan B compares to other Medigap letters

Plan B sits below the most comprehensive letters. Plans G and N are the most popular choices for people new to Medicare today because they cover more — for example, SNF coinsurance and foreign travel emergencies — which Plan B does not.

Plans C and F, which covered the Part B deductible, are no longer available to people who became eligible for Medicare on or after January 1, 2020, under the federal rules (MACRA). Plan B was not affected by that change because it never covered the Part B deductible. If you became eligible before 2020, your available options may differ.

Because every insurer must offer identical Plan B benefits, comparison shopping comes down to price and the company's pricing method (whether premiums rise with age). Always compare quotes from multiple carriers for the same letter.

Costs and when to enroll

Plan B premiums are not standardized and vary by insurer, your age, where you live, and sometimes tobacco use. We don't publish a single national premium because there isn't one — get current quotes for your ZIP code before deciding.

Your Part B premium is separate and continues regardless of any Medigap policy: $202.90 per month in 2026, with a $283 annual deductible (CMS). Medigap only helps with the cost-sharing Original Medicare leaves after those amounts.

The best time to buy any Medigap policy, including Plan B, is during your 6-month Medigap Open Enrollment Period. It starts the month you are 65 or older and enrolled in Part B. During this window an insurer cannot deny you coverage or charge more because of your health. Outside it, you may face medical underwriting in many states.