Congratulations on the baby.
It sounds like you only need gap coverage for one month. Honestly I'd just get COBRA for that month so you're not switching plans twice in the same amount of time.
Though maybe I'm misreading your comments. What do you mean you won't have group coverage? Is your old employer completely disappearing and dismantling the health plan? Does your new employer only offer coverage for the employee?
To other parts of your question, you and your wife are allowed to be on separate insurance plans though I suspect her eligibility in the plan at the new employer would disqualify her from this MA plan (I'd look this up tho).
For the sake of argument though let's assume you're on HSA, she's on PPO. SHE is allowed to continue to use HER HSA funds already accumulated to pay HER bills but cannot contribute more. You can keep doing the normal HSA thing in your own account expect the fund limit is the same as for a single person, not a family.
If any person is covered by both an HSA and a non-HSA qualified plan, they cannot contribute to an HSA account for those months.
HSA contributions allowed in a calendar year are a little bit tricky when you're partially covered through the year. If you are HSA eligible in the month of December, you are allowed to contribute the maximum allowed for the year even if you were only covered for the one month, BUT you have to RETAIN HSA coverage until December of the next year or face a penalty.
If your coverage stops before December, you are allowed to contribute a portional amount of the maximum allowed. For example, if you had HSA coverage for January, February, and March, you could contribute 3/12ths of the maximum.
You should also see your HR department; it's their job to make sure you safely navigate the stuff on their end after all.
In any case, just breathe, do some reading, and take your time. You already have a job so I don't doubt you'll be fine. Good luck.
