Mom lives with my husband and me full time now. She is totally dependent upon us for food, transportation, hygiene, etc. My husband and I are on fixed incomes, as is Mom. She does have social security and a small pension. Can I charge for food, transportation (multiple medical appointments, etc). Is there an acceptable rate, do I need a written agreement? Will I need to claim this money as income?
But if you are still kinda young (50's) and can still build towards your SS, then an extra 20K income can actually pay off in the long run in the amount of SS you draw when you finally retire.
Alot of this will hinge on how much money mom has available. Like my mom has about $ 1,900 a mo between her SS, my dad's federal retirement and an annuity and had savings (spent down for NH). While my late MIL had like $ 500 a month in SS and that was pretty well it. My mom could have afforded 2K a mo to "pay" or have a personal services contract while my MIL couldn't afford a penny. So you need to look at that too.
Assandache7 idea of paying for utilities is really good if there is not enough hard money to do a personal services contract. Mom needs to write checks from her solo personal checking account that gets her SS and pension. So no future commingling issue with Medicaid (should she need to apply for it) or SS.
Good luck.