@dmertz wrote:
"You can split those amounts any way you like."
Not quite. The 8-month pro-rated family limit of $5,166 can be split any way you like, but your $666 catchup must be contributed to your HSA and the 4-month pro-rated single limit of $1,283 plus your wife's $1,000 catchup must be contributed to her HSA, not to your HSA.
Yes. I had to recalculate several times after re-reading the question and trying to determine which assumptions to make about the original taxpayer's plans for insurance coverage. That caveat got left off.
Also note that, if you were going to keep the family coverage Marketplace plan after going on Medicare, your wife's limits would be calculated differently and would be higher.
