Medicare Advantage vs Medigap: The Real Cost at 65, 75 and 85

At 65, one Medicare letter says $0 premium and the other says about $166 a month. Most people decide in four seconds. 

But this is the one Medicare choice that can be very hard to undo. So we put Medicare Advantage and Medigap (Plan G) side by side: the monthly bill at 65, 75 and 85, a good year, a bad year, the break-even point, and twenty years added up. 

The honest result surprised us: in pure dollars, Advantage usually costs less. Then we look at what the dollars don't show: networks, prior authorization, plans that change every year, and the Medigap lock-in that most people only learn about when it's too late.

How we calculated, per person:

Part B premium left out, because you pay it either way.   

Plan G premiums by age from one large broker's 2026 sales data (not a national average), plus a standalone drug plan at $36/month (CMS 2027 projection), plus the $283 Part B deductible.

Medicare Advantage: average premium $12/month (CMS 2027 projection). A normal year is assumed at $500–$800 in copays, and a bad year hits the 2027 in-network maximum of $9,850.

These are examples, not advice. Get real quotes for your ZIP code, and talk to a free SHIP counselor before you switch.