You really need to go to this UNited Healtcare site:
https://info.aarpmedicareplans.com. You enter your zip code and then click the county, if the zip code covers more than one.
In my case, it gave me three advantage plans, nine Medicare Supplement plans, and three drug prescription plans. I next clicked on Medicare Supplement Plans. There are Plans A, B, C, D, etc. Rates run from $83 to $148 per month, but yours may be different, and remember that these costs are beyond what you pay for Original Medicare. It also gives you a very simple table of what is covered under each plan.
I chose Plan F because it pays 100% of everything in the U.S. and even 80% of foreign emergency care. It has paid every penny of annual visits, mammograms, bone density, colonoscopy, plus some serious tests and recent procedures ($25,000 worth).
IN other words, I have absolutely NO out of pocket costs.
BUT THAT DOES NOT MEAN EVERY PLAN THEY OFFER COVERS THOSE THINGS! So you really cannot be lazy ,and you do need to check. I have had some major things happen to me in the past, like a $140,000 stay in the hospital 8 years ago for pancreatitis. I also have recently been diagnosed with something that will mean huge bills in the future. (Don't worry, I'm NOT dying anytime soon and don't expect this to affect my life expectancy!!!) My point is that I chose the most expensive plan that covers 100% of everything so I don't have to worry about medical bills. For me, the extra $60 per month is well worth it. But you have to look at your costs and make decisions based on your expectations and worry-rate, so please don't make your decision on what someone else has done.
However, I do not have any dental coverage at all.
I don't know what plan Steven has, but you need to find out what it was and how it is different from these offered by AARP/United Healthcare. I suspect he does not have a Medicare Part C supplemental plan, which is what United Healthcare is offering. Most Advantage Plans, however, do have out-of-pocket costs, to my understanding.
The cheapest way to get coverage is to get a Medicare Advantage Plan, but for those of us who travel and want a choice of where we get treatment, that is not possible. For example, if I had had an Advantage plan from Ohio, I could get emergency care anywhere, but would have had to return to Ohio to get annual medical exams, and routine tests such as colonoscopy, mammograms, and the hand surgery I had twice in the past two years. This way I can get it in Ohio and in California or wherever I decide to be when I get treatment.
So you have to decide where you want to be able to get coverage.