My husband and I both have Parts A & B with his company medical then becoming the supplemental. We also are very fortunate to have drug coverage through his company.
Bear in mind that Medicare has a deductable and once met will pay 80% of their acceptable fee after which your your secondary will pay their 20% of the balance after Medicare.
Totally confused?
Do as another poster has suggested, get an appointment with your husband's HR person, I'm sure you will get help from them.
Once you get the hang of it, you're going to find that it's really easy to figure out. Medicare dictates what the Participating provider get's paid which amount to diddles, the writeoff will amaze you.
People definitely don't become doctors to make money anymore.