One off the things I learned pre-retirement is that a lot of medical practices are not accepting new Medicare patients. So, if you plan to relocate in retirement do it while you have good insurance, commute for a year if you have to, and get all of your doctor's in place.

Not nitpicking but your comment is not correct. Actually, although it's not really complicated, it is a little confusing.

Here's how it works (I believe:)) Tricare For Life (TFL) piggybacks off of Medicare, which is to say that you must use a provider who accepts Medicare, in order for TFL to pick up any expenses above and beyond what Medicare will pay. Those expenses are usually your out-of-pocket, or 20% of the original bill, as Medicare only pays 80% of the Medicare/Provider agreed upon fees. However, that is not always true, as in certain cases, such as those where Medicare doesn't cover a particular procedure, but TFL might. As an example certain vaccinations or shots are not covered by Medicare, but are covered by TFL. In those cases, Medicare would cover the office visit, but the uncovered procedure might be picked up by TFL, minus of course deductibles, etc.

This from the TFL Handbook: "Providers who opt out of Medicare enter into private contracts with patients and are not allowed to bill Medicare. Therefore, Medicare does not pay for health care services you receive from opt-out providers. When you see an opt-out provider, TFL pays the amount it would have paid (normally 20 percent of the allowable charge) if Medicare had processed the claim and you are responsible for paying the remainder of the billed charges."

As well, there are certain healthcare professionals who have elected not to accept Medicare, that we as members of TFL can use, where TFL will pay a significantly larger portion of the charges/bill. These instances are few and far between, but they do exist. To find out which providers are covered by this exception, I'd suggest a call to TFL.

Hope this clears things up a little, or if not, just stimulates someone to "get into the books." And speaking of books, here's a link to some valuable Tricare information: TRICARE Plans - TRICARE For Life

I guess the confusing part is "when my wife had Tricare as a secondary insurer". Most of us who have Tricare as a secondary insurer have Aetna or something like it for primary. In which case the primary essentially determines the reimbursement, unless as you say it is something Tricare covers and the primary doesn't. I suppose Uncle Sam does play games if they are the primary and secondary insurer.