So I realized that I never responded (and thanks for the reply). Yes, my wife has her own HSA and she went on Medicare as of July 1. The insurance we were on (I'm still on) is retiree coverage from my former employer and it was both poor and expensive, with the HSA being the only redeeming value. It was so bad that they didn't even cover preventive care at 100% when the ACA mandated it, because it was not required by law for this plan. So we are getting off it as soon as we can, which was July for my wife and November for me. The Medicare enrollment was not back-dated and I had previously checked elsewhere and am fairly comfortable saying that it only starts the month that your benefits actually started.
For 2020, I calculate that I can contribute $6066.66 in total, which is based on
$3500 for half the year at the $7100 family plan limit,
$1183.33 for four months on an individual plan ($3550 yearly limit),
$500 for six months of the $1000 catch-up for my wife and
$833.33 for me at 10 months.
For 2019, I calculated that I could contribute $7500 in total, which is based on
$5833.33 for ten months at the $7000 family plan limit,
$833.33 for ten months of catch-up for my wife and
$833.33 for ten months of catch-up for me.
Had i planned to be on the HSA plan for all of 2020, I could have contributed the full $9000 last year. But since I was not, I had to pro-rate.
There are a bunch of HSA contribution calculators on the web, but I haven't been able to find anything that takes my scenario into account, so an Excel spreadsheet had to do.
