Don't get Medicare Advantage or let your aging relatives buy it. There are cost advantages but they come with major disadvantages.
The biggest issue (by far) is that once you sign up with a Medicare Advantage plan you no longer access standard Medicare. You are completely dependent on the company you selected which gets a flat fee from Medicare to take care of your coverage, medications and how long you get to spend in the hospital. This means that they have a large incentive to minimize your care, and they do.
The companies have no problem refusing to cover beyond their estimate, regardless of what your doctor says you need. Just ask my dad who signed up with a large nationally known company. He had surgery for cancer and the insurance company determined he should be in the hospital for four days. There were complications and the surgeon recommended two more days. The insurance company would not pay more than their estimate. Even worse, they had a limit on a how much they would pay for pain medication so my dad ended up paying the difference on both the hospital stay and the additional pain medication. No amount of talking to agents or filing grievances with the company would budge them from their very firm estimates. From what I've read, this seems this is the norm for MA plans.
Medicare Advantage is less expensive than traditional Medicare coverage, but the cost savings will easily be lost if you actually need care. The insurance companies spend very heavily on advertising these plans because they make a crap ton from them.
