Thankfully if you have certain conditions and apply for Medicare you don't get the same kind of a bum's rush as you may with a large health insurance company.
Yes you may have to go through the medical underwriting routine in order for Medicare to determine what would work best for you (meaning you have lots of choices).
But, choices are good things to have when it comes to Medicare supplements.
Usually the way it works is you have Part A (covers your stay in hospital but not the services) and Part B (which covers your services).
Anything else you have over and above those two parts is rather like gravy.
For instance, Part D - which is your drug coverage.
Then if you have "gaps" in your health care coverage, you opt for Plan A through L for the extra bells and whistles.
Confusing to say the least, which is why talking to a knowledgeable insurance agent, makes sense.
No sense trying to sort through all the Parts and Plans on your own when agent advice is free and quite specific to your circumstances - and everyone one has a different set of circumstances.
For instance, in Texas you're guaranteed issue when you're enrolled in Part B.
Or if you are just coming off a group health plan you're guaranteed issue in 63 days.
Now having said that, there are course a significant number of exceptions to the rules of thumb.
The one thing you may count on it that health insurers have different guidelines for medical underwriting and for pricing.
Talk to an agent and don't waste time trying to figure out what situation applies to you, as you're likely to miss the boat on that one.