Investing via power of attorney for incapacitated principal

External question — Personal Finance Stack Exchange Author: thisisnotatest Original post: https://money.stackexchange.com/questions/150007 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. Can I use a financial POA to invest for an incapacitated principal? Or do brokerages commonly refuse to do so? i.e. POA must be setup on an account while they are in good health. My father has Alzheimers, he designated me to be his attorney in fact (financial power of attorney) before he fell ill. I am a successful trader and want to invest some of his money to help pay for his care, ideally with Ameritrade. It sounds like the best/simplest way to do this is to use the POA to do so, but reading through Ameritrade's documentation I have the impression it would need to be setup before he took ill. It sounds like Interactive Broker's 'Family Advisor' might be an option. https://www.interactivebrokers.com/en/accounts/family-advisor.php looking for advice/solutions thank you