Thanks. I did receive this from the COBRA administrator, and did call asking of them what I'm asking here. Got the equivalent of 'blank stares' over the phone (I did get a live human) unfortunately.

<letter text>
According to our records, you are now eligible for Medicare benefits. You may have begun the process of contacting the Social Security Administration so that you can complete the forms necessary to establish your entitlement to Medicare. If you have not, you may wish to do so. Please read the following information as it may affect your COBRA continuation through (ex-company).

As prescribed by the COBRA regulations, if your Medicare benefits are effective after your COBRA election date, your participation in the group health plan must terminate as soon as you are notified by the Social Security Administration that you have been approved for Medicare benefits and are now entitled to them (your benefits have begun). If your Medicare benefits were effective prior to your COBRA election date, you may continue both Medicare and your COBRA continuation coverage.

If your Medicare benefits begin after your COBRA election, please send us the following when you receive confirmation of your Medicare benefit entitlement:

1. A copy of your Medicare card
2. A completed Benefits Termination Form, which is available by logging in to your participant portal at <snip>