Medicare Supplement

How Medigap plan letters work for Mission, Texas readers

MISSION, Texas — If you're new to Medicare, or helping a parent sort through the mail, you've probably run into the word "Medigap." It sounds like jargon, but the idea is simple: Medigap is private insurance that helps pay some of the costs Original Medicare leaves behind. What trips people up is the alphabet — Plan A, Plan G, Plan N, and so on. Here's a plain-English guide to what Medigap does, what it doesn't, and how those standardized letters actually work.

Medicare Supplement insurance, explained: what Medigap does and doesn't cover

What Medigap is (and what it isn't)

Medicare Supplement insurance, often called Medigap, is a policy you buy from a private insurance company to work alongside Original Medicare (Part A and Part B). It helps cover things like coinsurance, copayments, and hospital deductibles that Medicare doesn't pay for on its own.

A few things Medigap is not:

• It is not Medicare Advantage (Part C). Medicare Advantage replaces Original Medicare with a private plan. Medigap works with Original Medicare. You cannot have both at the same time.
• It is not drug coverage. Medigap policies sold today do not include Part D prescription coverage. If you want help paying for medications, you'd add a stand-alone Part D plan.
• It is not dental, vision, hearing, or long-term care.

Think of Medigap as a partner to Original Medicare that fills in cost-sharing gaps — nothing more, nothing less.

How the standardized letters work

Here's the part that confuses almost everyone: in most states, Medigap plans are standardized by the federal government. That means Plan G from one insurance company covers the exact same benefits as Plan G from another. The letter tells you what's covered; the company just sets the price and the service.

Currently, Medigap plans are labeled A, B, C, D, F, G, K, L, M, and N. Two of them — Plan C and Plan F — are only available to people who became eligible for Medicare before January 1, 2020. If you turned 65 after that date, those two letters are off the table for you.

Each letter offers a different mix of coverage. Some cover almost every out-of-pocket cost under Original Medicare. Others cover less and, in exchange, tend to have lower premiums. Plans K and L have their own yearly out-of-pocket limits, which the higher letters do not.

Because the benefits inside each letter are set by law, the smart shopping question isn't "which company has the best Plan G?" — it's "which company offers the price and customer service I want for the letter I've chosen?"

Your best window to buy: the Medigap Open Enrollment Period

Timing matters more with Medigap than with almost any other Medicare product. Your Medigap Open Enrollment Period is a one-time, six-month window that starts the month you're 65 and enrolled in Part B. During that window, insurance companies must sell you any Medigap policy they offer at their best available rate — they can't turn you down or charge you more because of your health history.

Outside that window, in most cases, insurers can use medical underwriting. That means they can ask health questions and either deny coverage or charge more based on your answers. There are some exceptions (called guaranteed issue rights), but they're limited.

For folks in Mission and across Hidalgo County, this is the single most important Medigap rule to understand. Missing that six-month window can make it harder — sometimes much harder — to switch policies later.

What Medigap costs, and what it doesn't cover

Medigap premiums vary by company, by letter, and by where you live. On top of the Medigap premium, you still pay your regular Part B premium to Medicare.

Medigap does not cover:

• Prescription drugs (that's Part D)
• Routine dental, vision, or hearing care
• Hearing aids
• Long-term custodial care in a nursing home
• Private-duty nursing

If any of those matter to you, you'd need to plan for them separately.

Medigap vs. Medicare Advantage: a quick reality check

A lot of Mission-area readers ask us how to choose between Medigap and Medicare Advantage. There's no universal right answer — it depends on your doctors, your budget, your health, and how much predictability you want.

A few honest comparisons:

• Doctor access: With Original Medicare plus Medigap, you can generally see any provider in the country who accepts Medicare. Medicare Advantage plans typically use networks.
• Predictability: Medigap tends to trade a higher monthly premium for fewer surprises at the doctor's office. Medicare Advantage tends to have lower premiums but more variable copays and rules.
• Drug coverage: Built into most Medicare Advantage plans; added separately with Medigap.

Hidalgo County has multiple Medicare Advantage carriers and stand-alone Part D plans available, so if you go the Original Medicare + Medigap + Part D route, you'll have options to compare on the drug side too.

One more 2026 note that applies no matter which path you pick: Part D now has a $2,100 annual out-of-pocket cap on covered prescriptions, the coverage gap ("donut hole") is gone, and there's an optional Medicare Prescription Payment Plan that lets you spread drug costs across the year in monthly installments.

Key dates to keep on your calendar

• Your Medigap Open Enrollment Period: the six months starting when you're 65 and enrolled in Part B.
• Medicare Annual Enrollment Period: October 15 – December 7, for Part D and Medicare Advantage changes.
• Medicare Advantage Open Enrollment Period: January 1 – March 31, for people already on a Medicare Advantage plan.

Medigap itself doesn't follow the fall AEP — you can apply for a Medigap policy any time of year, but outside your one-time open enrollment window, underwriting usually applies.