I've been on Medicare for 2 yrs, and spent much time researching my options. I chose straight Medicare (A & B) + Plan D with Aetna + Plan G with Aetna. Of course I didn't want to spend a lot in premiums (my total premiums almost $400/mo). The best decision I've ever made!! And worth every penny. Was very healthy at 65, but the "what ifs" concerned me. Indeed, the what-ifs have happened nonstop since then...surgeries, hospitalizations, multiple specialists, very expensive meds. The fantastic news is I never have to worry about out of pocket expenses-- no co-pays anywhere, no referrals required (can see any doctor I want in the U.S.). Because of Plan G, I am 100% covered. Advantage plans have limitations, restrictions, and don't cover everything. I've got friends who regret choosing & they switched. Being ill is stressful enough, but at least I don't have any money stress for any/all the care I need. I'm not thrilled with Plan D, however, I take an extremely expensive med that I could never afford without Plan D. My monthly outgo for the Rx is only $47, vs. $600/mo. Good luck to you. P.S. Medicare.gov reps are extremely helpful. They've helped me several times (Medicare.gov).