Medicare Supplement

Medicare Supplement standardization explained for Biddeford

BIDDEFORD, Maine — If you're new to Medicare or helping a parent sort through the mail, the alphabet soup of Medicare Supplement plans can feel confusing. Plan A, Plan G, Plan N — what do the letters actually mean, and why does one insurer's "Plan G" look identical to another's?

The short answer: because the federal government requires it to. Medicare Supplement Insurance, commonly called Medigap, is standardized by letter, which makes comparing coverage more straightforward than most parts of Medicare. Here's how it works.

What Medigap Does

Medigap is private insurance that helps pay some of the out-of-pocket costs Original Medicare (Part A and Part B) leaves behind — things like coinsurance, copayments, and hospital deductibles. It works alongside Original Medicare, not instead of it.

When you have a Medigap policy, Medicare pays its share of an approved cost first, and your Medigap plan pays its share second. You still pay your monthly Part B premium, and you'll typically pay a separate premium for the Medigap policy itself.

Medigap does not include prescription drug coverage. For that, most people add a stand-alone Part D plan. Medigap also does not work with Medicare Advantage — you generally cannot use both at the same time.

Why the Plan Letters Exist

Before the 1990s, Medigap policies varied wildly from company to company, and shoppers had a hard time comparing them. Congress fixed that by requiring the plans to be standardized. Today, in most states, Medigap plans come in 10 standardized options identified by letters: A, B, C, D, F, G, K, L, M, and N.

Here's the key point: a Plan G sold by one insurance company covers the exact same benefits as a Plan G sold by any other insurance company. What can differ is the premium, customer service, and how the company handles rate increases over time — not the coverage itself.

Massachusetts, Minnesota, and Wisconsin standardize their Medigap plans differently, but Maine follows the standard letter system.

What the Letters Generally Cover

Each lettered plan covers a specific mix of benefits, such as:

• Part A hospital coinsurance and extra hospital days after Medicare benefits are used
• Part B coinsurance or copayment
• The first three pints of blood
• Hospice care coinsurance
• Skilled nursing facility coinsurance
• Part A and Part B deductibles (varies by plan)
• Foreign travel emergency care (varies by plan)

Plans K and L work a little differently — they cover a percentage of certain costs and include an annual out-of-pocket limit, after which the plan pays 100% for the rest of the year.

One important note about newer enrollees: Plans C and F are no longer available to people who became eligible for Medicare on or after January 1, 2020. These plans covered the Part B deductible, and federal law now prohibits new Medigap policies from doing so. If you were eligible before that date, you may still be able to buy them.

When You Can Buy Medigap

The best window to buy a Medigap policy is your Medigap Open Enrollment Period — the six months that begin the first month you're 65 or older and enrolled in Part B. During that window, insurance companies cannot deny you coverage or charge you more because of health problems.

Outside that window, in most states, insurers can use medical underwriting, which may affect whether you can get a policy and what it costs. Maine has some additional consumer protections around Medigap enrollment, so it's worth calling the state's insurance program before assuming you can't switch.

How This Fits with the Rest of Medicare

Biddeford is in York County, where residents have access to Original Medicare nationwide, plus a range of Medicare Advantage and Part D plans offered at the county level. Medigap is a different track: it pairs with Original Medicare, not with Medicare Advantage.

A few 2026 program-level figures worth knowing as you plan:

• Part D has a new $2,100 out-of-pocket cap on covered prescription drugs in 2026.
• The Part D maximum deductible is $615.
• The old coverage gap (the "donut hole") was eliminated in 2025; Part D now has three phases.
• IRMAA income surcharges for higher earners begin above $109,000 for a single filer in 2026.
• The Annual Enrollment Period runs October 15 through December 7, and the Medicare Advantage Open Enrollment Period runs January 1 through March 31.

These figures apply to Part D and Part B, not to Medigap directly — but they shape the coverage decisions that sit alongside Medigap.