In terms of Medicare Advantage plans, they vary by zip code. For instance, I am working with a disabled (under-65) woman in Spokane WA to find her a good Medicare Advantage plan. Here in the Orlando area, she could get a Humana PPO for $0 premium, and because her meds are all generic, she could pay $0 for medicines with mail-order. Out there, PPOs from Humana and Aetna have a $100-ish/month premium. HMOs are inexpensive, but her doctors are not in the Humana network, only a couple take United Healthcare, and most take Aetna. Her only specialists are Ob/Gyn, chiropractor, and psychiatrist (neither require a referral). All plans from my 3 plans pay for mental health care.
Or, my sister-in-law who lives in Thousand Oaks CA is now Medicare-eligible. If she joined up with any of "my" Medicare Advantage plans, she would have an additional premium HMO. There are no PPOs in that part of Southern California, even in plans that I do not offer.
Or, I had a Medicare-eligible guy ask me a couple years ago about Mount Shasta CA. They do not have one single MAPD. They're only eligible for a Medicare Supplement + PDP. He was on our company's HSA plan and is not retired. The reason is, his area had a PFFS (Paid Fee For Service) plan through United, but they stopped offering it. PFFS is like a PPO, they can go to any doctor who accepts Medicare, BUT the doctor can deny that one plan if they choose.
So, if you look at any posts of people here saying they have x benefits with their MAPD with a certain company, your area's benefits are most likely different.
TS