Being able to enroll in Medicare is one of the major benefits of getting older, right after qualifying for the five-percent-off senior discount at the supermarket. 

Like many of us, I thought enrolling in Medicare would be easy. I figured I’d have to prove I was 65 by remembering who won Super Bowl III (the New York Jets) and who was the Beatles’ drummer before Ringo Starr (Pete Best), but then I’d automatically be covered because … well, that was the American way.

Well, not exactly. Just like the American way, with its tolls every few miles, dangerous curves up ahead, and lack of a single clean rest stop, Medicare frequently has co-pays every few visits, dangerous deductibles up ahead and also not a single clean rest stop.

Medicare, it turns out, is actually not one whole plan but many different plans. The first part is Part A and sometimes Part B. Then there’s the party of the second part, which is Part C and Part D. Altogether, sort of, these parts are colloquially called “Original Medicare.” Because, why not?

Medicare Part A is essentially hospital insurance. You insure the hospital you won’t need to go there often. If you appear too frequently, you pay full price for one surgery but at least get the second one 50 percent off.

Medicare Part B covers certain doctors' services but only ones you will probably never need. These include what is generally known as outpatient care, which means you generally will be out a good bit of money.

Medicare Part A doesn’t cost anything, which is probably why it doesn’t cover much of anything. You actually do pay for Part B, with your premium set each year by a group of actuaries bored with playing fantasy football.

Then there’s Medicare Part C. Well, technically, there is no Medicare Part C.

It’s just called Part C, sometimes, to further mystify us in case we weren’t already so mystified we have started eating our soup with a fork. Part C is more commonly called a Medicare Advantage Plan. Advantage plans are offered by a private insurer that has made a sweetheart deal with Medicare, which was too busy writing confusing enrollment guidelines to pay attention.

Designed to make up the difference between what Medicare pays and what the federal deficit is, an Advantage plan provides all the Part A and Part B benefits, plus, maybe, a side of fries. Most also provide Medicare Part D benefits, which is prescription drug coverage because it would have been too simple to call it Medicare prescription drug benefits.

There’s also a Dual Complete Plan, which is like an Advantage plan but may be something entirely different after all is said and done. Or it could be the exact same thing under a different name because health insurance companies want to keep us on our toes.

These plans cover 20 percent of this and 35 percent of that or 100 percent of something else (after the first 35 percent) and 60 percent of the second 25 percent, minus the 18 percent co-pay, for days one to six if you are an inpatient and can read the third line of the eye chart. Assuming, of course, you are in network.

Then there’s a Medicare Supplement Plan, which is different from a Medicare Advantage Plan because it does not include Plan D prescription coverage but does include everything else and doesn’t make you pay co-pays after you meet your deductible, which you could do some enchanted evening across a crowded room. A Medicare Supplement Plan is also sometimes called a Medigap Plan in a largely successful effort to give many of us migraine headaches.

If you get a supplement plan, you will have to get a separate Part D prescription plan, but there may be none left because you have taken so much time figuring out all the previous parts.

Many different private insurance companies offer these supplement plans. Each company tells you its supplement plan is better than every other insurance company’s supplement plan. In fact, they are all exactly the same because the government requires them to be exactly the same but the companies don’t want to tell you that because it might actually help you make a decision instead of slapping yourself upside the head trying to choose among them.

If you are confused by all this, and also don’t understand how which plan you can get and how much you will pay for it also will depend on where you live, how old you are, if you ever smoked or attended a KISS concert, and whether you are still breathing, be comforted by the fact that you have made the insurance companies very happy.

By the way, you can only enroll in any of these plans during a precise period of the year, called the open enrollment period. If you try to enroll outside that time, you will be made to pay a higher premium and forced to read the 723-page Medicare Annual Notice of Changes in its entirety.

[This story is adapted from Neil Offen’s new book, Building a Better Boomer.]