A Medicare Supplement — also called Medigap — sits alongside Original Medicare and pays toward what Original Medicare leaves behind. It is not a replacement for Medicare, and it is not the same thing as Medicare Advantage.

The problem it solves

Original Medicare leaves you roughly 20% of each Part B service with no annual cap. A Supplement covers much of that, turning an open-ended exposure into a predictable monthly premium. That predictability is the entire proposition.

Standardisation, and what it means for shopping

Medigap plans are standardised by letter. The basic benefits of a given letter are the same from one insurer to the next — a Plan G is a Plan G. What differs is the premium, the underwriting, discounts, and how the company behaves at claim time.

That makes this one of the few insurance decisions where comparing on price is genuinely sensible, because the product really is identical. It is also why working with a licensed agent who can see multiple insurers matters more here than almost anywhere else.

Timing is the critical part

Your Medigap Open Enrollment Period is the six months starting the first month you are 65 and enrolled in Part B. In that window you cannot be turned down or charged more for health reasons. Outside it, Supplements are generally medically underwritten, and a health condition can mean a higher price or a refusal.

This is the most consequential deadline in Medicare and it does not come round again.

The Tennessee rule that sets the state apart

Federal law does not require insurers to sell Medigap to people under 65. Tennessee requires it: any insurer selling Medigap to people 65 and over must offer the same plans to people under 65 who have Medicare because of a disability or ESRD.

That is the broadest position of the three states The Jordan Insurance Agency serves. North Carolina guarantees Plan A plus D or G. South Carolina requires nothing of private insurers at all. If your Medicare came from a disability, Tennessee gives you options a short drive south would not — see Medicare before 65 on disability in Tennessee.

Supplement or Advantage

Different structures, not better and worse. A Supplement does not route you through a network; a Medicare Advantage plan caps in-network spending and often bundles drug coverage. See how Medicare Advantage works in Tennessee.