WWWMMD? Insurance for mom.

I'd say risky plan. You save money, and there's a low chance and a short time frame for something to go wrong. You also have the backup of Kid A paying the extra 5k. I don't see much risk with this choice.

With enough googling and patience it's possible to start working out the odds at least a little.
SEER Cancer diagnosis incidence by Age and Race for women
Long-Term Trends in Medicare Cost Concentration
etc. etc. Even for diabetics Medicare benificiaries, the chance of being high cost in a given year is only about 10%. And mom is not in great health but she is not in the unhealthiest set of diabetic Medicare patients. So we guess her risk of having super-high medical expenses is somewhere around 5% in the worst case. Even if we take her chances at 10% the math on which plan is better stays about the same ... a poker player would still never take the Expensive plan, but the numbers start getting closer.

The Expensive plan is only better than the Risky Plan if mom ends up as one of these truly nightmare cases. Even with a $10,000 hospitalization the plans are about the same. It would take something that cost $30,000+ for the Expensive Plan to be a better deal. Cancer is obviously something that would cause that. So would certain diabetes complications, end-stage renal disease, etc.

If there were more time between today and Obamacare or the disability claim being processed then the Expensive plan might make more sense. But with only 18 months I feel like it would be unnecessarily risk averse to go with the Expensive plan. We've already rejected a different plan that was actuarially "better" because it had a higher OOP maximum.

Just realize that dollars add up very quick when it comes to hospitalizations. My appendectomy bill was about $15K and routine childbirth was about $25k. Your average hospitalization will be much more than $10k and 1 hospitalization may put you over the 30 K mark...