The comments (at the end) are worth taking a look at, as they raise questions/with some answers on: Medicare, Supplement Plans, Advantage Plans, etc.
If you're an AARP member, you should get an email with an article titled:
"8 Things Medicare Doesn't Cover." Most of this is pretty well known (although challenged in some of the comments) but the comments are probably more worthwhile than the article. If you don't belong to AARP or the link below doesn't work, try googling the title of the article. I'm putting this under the "Medicare Open Enrollment" topic although it's not really about that -- but I don't see a general "Medicare" title.
https://www.aarp.org/health/medicare-insurance/info-2018/services-not-covered.html?cmp=EMC-DSM-NLC-OTH-WBLTR-1309502-1597905-6393373-NA-052822-Webletter-MS1-8Things_MEDICARE-BTN-MCTRL-HealthHygiene&encparam=4kDGzelnd%2fs1Dhf2Mj4PAq3C5%2bTwJ7aq%2f0ZUv%2bzsv60%3d
Health insurance counseling is one of those needs. In MA, they are SHINE counselors (Serving Health Insurance Needs of Elders/Everyone.) Other names in other states. The local Council on Aging or county department on aging can tell you how to locate one of them. They provide unbiased information on health insurance options, and explain some of the language...and the different timelines/application dates, etc.
Even a phone conversation can help. Every supplemental policy that you buy, including Medicare D (drugs) are purchased by you from private insurance companies. Payroll saving cover some of the costs of Medicare A and B.
Medicare rates are based on your income, so you may be required to pay for your Medicare A and B, along with D and all the supplements for A and B. You choose what seems like the best coverage for you at the cost you can afford.
An advantage plan is like an HMO - all in one coverage, plus extras not covered by standard Medicare, at one fixed monthly cost (based on your county,) Seems easy and stressless - until you are seriously ill or injured and discover that your insurance case manager works within limits of contracts to choose most cost effective care for you. Quality of care varies widely.
I've also experienced poor support from staff when switching to insurance. One of their staffers had a very strong sales pitch for auto insurance, sent me the forms, which were so poorly constructed that much of the printed section wasn't even readable.
I told the agent, and said that I'd have to print it out and see if I could read it any better (I couldn't.). The next day the order was cancelled because I "didn't respond in a timely matter." So I won't even consider AARP's insurance anymore. I'd rather deal with a professional agent.
"Your Medigap policy may offer additional coverage for emergency health care services or supplies that you get outside the U.S. Standard Medigap Plans C, D, F, G, M, and N provide foreign travel emergency health coverage when you travel outside the U.S."
Be be very careful when selecting an MA. You better be sure it fits your health needs. That the doctors you go to are part of their network. Do you really need all they offer? Would having straight Medicare and a suppliment be better?
I am lucky. My husbands union provides our supplimental, vision, prescriptions and dental so straight Medicare is enough for us. Because my suppliment is BC/BS and the company my husband worked for is national we can use it anywhere. But that may change. We just got a letter talking about a new MA they will be introducing this Fall. For now we have choices but that could change.
Don't think that AARP is not getting a kick back to push MAs. You need to be very informed and know all the ins and outs concerning any health insurance. Your best place to help you is your local Office of Aging.