Financial Basics · Healthcare

Medigap

Medigap (Medicare Supplement) is private insurance that covers the 20% coinsurance and other out-of-pocket costs Original Medicare doesn't pay. Plans are standardized by letter (A through N) with Plan G being the most comprehensive available to new enrollees.

By the TRRP Editorial TeamUpdated 2026SSA · IRS · CMS data

Definition

Medigap (Medicare Supplement) is private insurance that covers the 20% coinsurance and other out-of-pocket costs Original Medicare doesn't pay. Plans are standardized by letter (A through N) with Plan G being the most comprehensive available to new enrollees.

Why it matters in retirement

Paired with Original Medicare and a Part D plan, a Medigap policy gives you nearly unlimited medical coverage with almost no out-of-pocket cost and no network restrictions. For many retirees this is the gold standard — if you enroll during your open enrollment window.

Key numbers · 2026
Avg Plan G premium (65)
$150–$250/mo
Plan G deductible
$283 (Part B, 2026)
Open enrollment window
6 months from Part B
Part B coinsurance
20% (uncapped)
Pros
  • No network restrictions
  • No prior auth
  • Predictable costs
  • Guaranteed renewable
Cons
  • Higher monthly premium than Advantage
  • No dental/vision/hearing
  • Premiums rise with age (attained-age plans)
  • Must apply during open enrollment or face underwriting

Common mistakes

  • Missing the 6-month open enrollment window
  • Buying Plan F (no longer available to new enrollees after 2020)
  • Not comparing Plan G vs Plan N (Plan N often saves money)
  • Ignoring "community-rated" vs "attained-age" pricing
The part most people miss

Medigap premiums vary 30–50% between carriers for identical coverage — the letter of the plan is standardized, the price is not. Shop at least 5 carriers before you buy.

When you’re ready

Want help applying medigap to your situation?

Start with the free Retirement Readiness Score to see where you stand, then talk to a fiduciary if you want a second set of eyes. No pitch, no pressure.

Take the free assessment