Can I change my health plan when my spouse becomes eligible for Medicaid or Medicare and enrolls?
If you or your spouse become eligible for health insurance from a program like Medicaid or Medicare it counts as a qualifying life event and you can change your coverage. The same is true for losing eligibility for one of those programs.
The same is true for dependents and spouses and CHIP.
Essentially it works like this, if you were on a family plan and they enroll in Medicaid or Medicare after becoming eligible, then you can change to an individual plan. And vice-versa, if you were on an individual plan and they stop being eligible for Medicare or Medicaid and dis-enroll you can switch to a family plan.
In general you would plan this to ensure there was a small a gap in coverage as possible for everyone. You can always call the marketplace for assistance!