I’ve T1D and switched from a G to a F Plan last year - but not for the coverage or the premium.
There is no financial benefit to using one company’s basic Plan B Supplement Plan over another besides the premiums you pay. Premiums vary between companies but the coverages are identical for all basic type F Plans and all type G plans. If your doctors accepts Medicare, they get paid the same. Medicare forwards the approved copay charges to the supplement carrier (which is 20% for both F and G.)
Medicare is phasing out Plan F in a misguided attempt to to “motivate” people to see doctors less often. The only difference between F and G is the annual deductible. It’s included in the Plan F premium, not the plan G premium so for a given carrier Plan G premium should be ~$20/mo cheaper than Plan F in 2024.
That is the only difference, and 2-3 visits are enough to cover the Part B $240 deductible. After that there are no more uncovered Part B charges.
Only if you are switching from an Advantage Plan to regular Medicare, may carriers require you to qualify for a Medicare B Supplement.
Unless you were previously enrolled in a Medicare “Advantage” (Part C) plan, there are NO pre-existing condition restrictions on what Part B Supplement plan you can enroll in. If you weren’t I’d suggest you use the Medicare.gov site to compare premiums and sign up. (You may find that Plan F isn’t available to you. )
Some companies add on “features” like discounts for preventive dental care and eye exams - gimmicks to get you to go to doctors in their network who seem to always find something that isn’t “preventive” care, and for which you pay a "discounted price.
Some companies, like Blue Cross Blue Shield have G “Select” Plans. If you are hospitalized at one of their “select” hospitals, the plan will cover the Part A deductible. In my region every major hospital is “select”.
Personally, I like the medicare.gov site and the annual booklet I’m sent in September. I have yet to have a question that these didn’t answer more clearly and unambiguously than any rep - in writing.
I’m skeptical about all insurance company representatives. The ones who are the employees of those companies are biased. The ones who are independent insurance reps are paid by the insurance companies to sell you their plans even though it doesn’t affect your premiums.