The whole difference is one deductible
Plan F pays the annual Part B deductible ($283 in 2026) and Plan G does not. That is the entire coverage gap between them. Everything else pays identically.
Why F usually loses its own comparison
F typically costs more than G by well over $283 a year. You are prepaying the deductible with a markup. Worse, F closed to newly eligible beneficiaries in 2020, so its risk pool ages without new blood, which tends to push its premiums up faster than G’s over time.
If you hold Plan F today
Do the subtraction once a year: your F premium minus a quoted G premium. If the gap exceeds $283, switching pays, if you can pass underwriting. That last clause matters; price out the move before letting F go, never after.
If you are new to Medicare
The F question is settled for you: it is unavailable. G is the most complete plan you can buy, N is the value play, and the smart move is comparing those two across carriers rather than mourning a closed door.