does Medicare coordinate with secondary insurance at all or does it just create more paperwork
trying to understand how Medicare works as a primary payer when my dad also has retiree coverage through his former employer. he just aged into Medicare this year and kept his old company's retiree plan because the premium is low and it felt like a safety net. but now I'm hearing that coordination between the two can get messy depending on which one pays first and how claims flow through
he has original Medicare with Plan G, so I assumed the supplement covers most of what Medicare doesn't. what I genuinely don't know is how the retiree plan fits in now. does it basically become useless since Plan G is already covering the gaps, or does it kick in somewhere? and the Part D piece is a separate question entirely because his retiree plan has drug coverage too, and I have no idea if he was supposed to drop one of them
I do a lot of spreadsheet work for a living so I can handle complexity if someone explains the actual logic. every article I find either oversimplifies it or assumes I already know what coordination of benefits means in practice. his HR contact told him to call Medicare, which is not a useful answer.
has anyone actually dealt with layering retiree coverage on top of original Medicare and figured out whether it helped or just added friction?