What a Medigap policy is, and what it is not

A Medicare Supplement — almost everyone calls it Medigap — is a private insurance policy that works alongside Original Medicare rather than replacing it. Medicare pays its share of a covered service first, and your Medigap policy picks up much of what would otherwise come out of your pocket. It is a companion policy, not a substitute, and it is a different animal from Medicare Advantage, which is an alternative way of receiving your Medicare benefits. You generally pick one road or the other; you do not drive both.

The gaps it is built to cover

Original Medicare covers a great deal, but it leaves real costs with you, and on its own it has no annual limit on what you can spend. That missing ceiling is the heart of the matter. Here is what sits in the gap, using 2026 figures:

  • The Part A hospital deductible of $1,736 per benefit period — and you can have more than one benefit period in a single year.
  • Hospital coinsurance of $434 a day for days 61 through 90, and $868 a day for lifetime reserve days 91 through 150.
  • The 20% coinsurance you generally owe on most Part B services once you have met the Part B annual deductible, which is $283.

Because that 20% has no cap under Original Medicare alone, one serious year can produce a bill with no obvious upper bound. Medigap exists to turn that into something predictable: a known monthly premium instead of an unknown annual exposure.

Standardized by letter, which is unusually helpful

Medigap plans are standardized by the federal government and named by letters, A through N. A given letter provides the same core benefits no matter which company sells it. What differs between companies is mainly price and service, not what the policy does. That is a genuinely useful feature for a buyer, and it is the reason comparison shopping across companies is worth the effort — you are comparing like with like in a way you rarely can in insurance.

You keep paying your Part B premium on top of the Medigap premium: $202.90 a month in 2026, and more for higher earners once modified adjusted gross income passes $109,000 for one person or $218,000 for a couple filing jointly, where the first bracket brings the Part B total to $284.10 a month.

No network — and in Nashville that is the whole argument

With Original Medicare and a Medigap policy there is no plan network. You can generally see any doctor or hospital in the country that accepts Medicare, without a referral and without checking a directory first.

That abstract benefit becomes very concrete in Nashville. Three large health systems — Vanderbilt, Ascension Saint Thomas and TriStar — all operate widely across the city, and it is entirely ordinary for one household to use two of the three: a primary care doctor in one system, a cardiologist or a surgeon in another, and a hospital nearby that belongs to a third. Families in Franklin, Brentwood, Hendersonville, Mount Juliet and Murfreesboro routinely drive into Nashville for one specialist and stay local for everything else. A Medigap policy does not ask you to choose between those systems or to re-check a network every January. For households built that way, that is usually the deciding factor rather than a line item on a benefits chart.

Tennessee's under-65 rule is the broadest among the states we serve

Federal law does not require insurers to sell Medigap to people under 65, and most states leave that gap open. Tennessee does not. Here, an insurer that sells Medicare Supplement coverage to people 65 and older must offer those same plans to people under 65 who have Medicare through disability or end-stage renal disease. That is a meaningfully broader rule than you will find in most places, and it means that if you came to Medicare before 65, Medigap is a real option here rather than a door that is closed to you.

Two things are worth saying alongside that. First, people who reach Medicare through Social Security Disability Insurance generally wait 24 months for Medicare to begin, and those months need not run consecutively; ALS and end-stage renal disease follow different paths. Tennessee has not expanded Medicaid, so that wait can be a hard stretch, and COBRA's disability extension of about 29 months is sometimes what bridges it. Second, and this is the reassurance people need: a choice you make under 65 is not your last chance. A full Medigap window still opens at 65 regardless of what you did before.

The six-month window at 65

Your Medigap Open Enrollment Period is six months long and begins the first month you are both 65 or older and enrolled in Part B. Inside that window you can buy any Medigap plan sold in Tennessee without answering health questions — an insurer cannot turn you down or price you differently because of your health history.

Once the six months close, insurers can generally use medical underwriting, unless a separate guaranteed issue right applies. Whether one is open to you depends on your own circumstances and gets checked against your record — it is never something to assume either way. In plain terms: if Medigap appeals to you, the window at 65 is when the decision is cheapest and most certain, because health changes later can narrow what is available. Our guide to when you can enroll in Medicare in Tennessee sets this window next to all the others, since they do not run on the same calendar.

Medigap does not cover prescriptions

This surprises people every year. A Medigap policy pairs with Original Medicare, and Original Medicare does not cover most medications you take at home. If you want drug coverage you buy a separate Part D prescription drug plan, often from a different company than your supplement. Going without one, and without other creditable prescription drug coverage, can add a lasting surcharge to your premium later — see how the Medicare late enrollment penalty works.

Worth noting as you compare: Part D plan availability can vary by county and ZIP code across Davidson, Williamson, Sumner, Wilson and Rutherford counties, so the drug plan that pairs well with your supplement in Nashville may not be on the list in Gallatin, Lebanon or Spring Hill. Our Medicare page for Nashville covers how we work across the region.

Is Medigap the right road for you?

There is no universally right answer, and anyone who gives you one without asking about your doctors has not earned your attention. Medigap tends to suit people who want predictable costs and freedom of provider and accept a higher monthly premium for it. Others prefer a different balance. The honest work is weighing the trade-offs against your own doctors, your medications, your budget and how much you travel.

How The Jordan Insurance Agency helps

Because the letters are standardized, our job is to compare the same letter across companies on price and service, watch the six-month window so it does not close behind you, and make sure the drug plan does not get forgotten in the middle of it. For anyone under 65 on Medicare, we will walk through what Tennessee's rule actually opens up for you rather than assume the door is shut.

The Jordan Insurance Agency is an independent, licensed insurance agency with a Tennessee office at 159 4th Avenue N, Suite 100, Nashville, TN 37219. You can reach us at (615) 558-6082, Monday through Friday, 8:00 AM to 4:00 PM Central. Because we are independent we represent multiple carriers rather than one, so we can lay your real options side by side instead of steering you toward a single company. A consultation with a licensed agent is free, and your premium is the same whether you enroll on your own or with our help.