All Medicare Part C "Medicare Advantage" managed care plans cover emergency medical care while you're traveling anywhere within the U.S. or Puerto Rico. The problem is finding a plan that would cover you for regular, non-emergency care in more than one geographic area.
Medicare Advantage plans enroll you based on your "service area," meaning a geographic area that includes your permanent residence. That's because the amount they charge you is based in part on the cost of medical services in that geographic area. To get full coverage from a plan, you have to get services from providers -- doctors, hospitals, clinics, laboratories, etc. -- who are in the plan's network within your service area.
Some plans can cover medical care outside your service area if you receive it from a provider who's in the plan's network in that service area. In those situations, you might have to pay a somewhat higher copayment. Other plans, particularly Preferred Provider Organization (PPO) plans, may cover you even if the care is from a provider who's not in the plan's network, no matter where you receive the care, but will charge you a much higher copayment.
To find and compare the best coverage offered by specific Medicare Advantage plans, you'll have figure out where you spend most of your time, or where the doctors are who you want to provide your regular medical care. Once you decide on this permanent residence for Medicare purposes, you can find all the Medicare Advantage plans sold in that geographic area by going to the Medicare Options Compare page on the Medicare web site. This will show you all the plans available in that area, and allow you to see what each plan's coverage is for care you receive while out of the service area.