Q. I have Blue Cross Blue Shield coverage, including prescription drug coverage, through my previous civilian employer. I'm also a military retiree with Tricare for Life drug coverage. I thought Tricare's Express Scripts, as second payer, is supposed to cover what BCBS does not. But Express Scripts is charging me a co-pay. I asked about this, and the answer, in effect, was "tough luck, pay up." What's going on?

A. You have stumbled across a bit of the fine print in Tricare-as-second-payer coverage.

When a beneficiary has double coverage, as you do, the other health insurance pays its benefits in full as the first payer. After that, Tricare will kick in as second payer and cover what is left — up to the amount Tricare would have paid if you did not have OHI.

In other words, even when Tricare is positioned as second payer to OHI, if Tricare is in fact called upon to kick in on a claim as second payer, all normal Tricare beneficiary co-pays apply.

You can get more details in an online brochure about how Tricare works with OHI.

Tricare's pharmacy contractor, Express Scripts, can be reached toll-free at 877-363-1303.

Q. I recently took disability retirement from the military at age 31. I had Tricare Prime, but received an application for Medicare coverage by mail. I opted only for Part A and skipped Part B because I figured I had Prime. Now I find out I'm no longer eligible for Prime because I'm eligible for Medicare. So do I have to pay for Medicare Part B and also Tricare for Life? I really wanted to keep Prime because it was simple and affordable.

A. You are no longer eligible for Tricare Prime precisely because you are now eligible for Medicare.

This transition normally happens for most people at age 65, but it arrives sooner for individuals like you who become eligible for Medicare earlier due to disability. You now must use Tricare for Life, under which Medicare acts as first payer and Tricare Standard acts as second payer. And enrollment in Medicare Part B outpatient coverage, and payment of the Part B premium — $104.90 a month for most people — is required in order for you to use the Tricare portion of your Tricare for Life benefit.

Under TFL, the Medicare Part B premium will be your only recurring cost; Tricare Standard charges no premiums. The combination of Medicare and Tricare Standard will cover 100 percent of your costs on the vast majority of your health care claims.

Contact your local Social Security office about getting enrolled in Part B. Once that's squared away, contact the Defense Enrollment Eligibility Reporting System to make sure your current status as a TFL beneficiary is reflected in the DEERS database.

You can engage DEERS by visiting the ID Card/DEERS office on any military installation or by calling the main DEERS support office at 800-538-9552.