Employer health insurance will overlap with Medicare

My wife and I will turn 65 in January and February of 2026 respectively. So, we’ll both be applying for Medicare some time around the end of 2025. I am retired and we are currently covered under my wife’s company’s health plan which is a high-deductible PPO with HSA. In January of 2026, the open enrollment period will have passed; we will have re-upped for my wife’s plan and so that plan and Medicare will overlap. What are our options?

Can we delay taking and paying for Medicare until either the next open enrollment period (for 2027) or my wife retires (whichever comes first)? I’d actually prefer to have medicare over my wife’s plan to get something with a lower deductible. However, I don’t think there’s a way to avoid signing up for her plan to avoid losing coverage for that short period in January and February just before we turn 65.

If we can delay taking Medicare, does the fact that we’re eligible for Medicare affect our ability to contribute to the HSA or does that come into play only if we actually take Medicare in which case Medicare becomes the secondary payer?

I’m sure the above scenario happens to many people, but a lazy Google search didn’t come up with anything specific.