Yes, you can switch from Medigap to Medicare Advantage plans during the Annual Election Period, which runs from October 15th-December 7th each year. Then, cancel your Medigap and/or Part D Rx plan. If Rx coverage is desired, you will want to sign-up for a Medicare Advantage with Prescription Drug (MAPD) plan.
Yes, If you have Medicare Part A and Medicare Part B and do not have ESRD (End Stage Renal disease) you can switch from a medigap to a medicare advantage plan during the annual open enrollment period (October 15th thru December 7th ) and have a January 1st effective date. Once accepted you can then cancel your medigap and/or PDP (Prescription Drug Plan) with a January 1st termination date. I would recommend locating an independent agent who specializes in Medicare to help you thru this process...
Your Medigap plan most likely has less than $500 out of pocket if you have a bad year. You have $0 out of pocket with plan F and $2110 with Hi F.
Medicare Advantage has an out of pocket of $2700 to $5700 PLUS your OON charges.