Medicare & multiple supplements for retiree

[Guest mat]

One of our post-65 retiree's visited recently and advised they had improved their benefits. They utilize Medicare A&B, then our limited retiree health plan and now an individual supplement they purchased on their own. In order to process a health claim they(their health provider) submits the charges to Medicare, then the balance of the unpaid claim is sent to our insurer for processing under our limited retiree health plan which is a Medicare Supplement. When they receive our EOB they send it to the individual medicare supplement carrier for balance reimbursement. In some instances, they avoid our plan and submit the Medicare EOB directly to their individual carrier for reimbursement. An example, we provide little in the way of Chiropractic benefits - the retiree skips us and goes directly to the individual carrier for reimbursement.

Is this legal? Can the retiree jeopardize their Medicare coverage or can they be dropped from our plan for "duplicate" coverage?

MAT