No, you can leave assets to a non-related caregiver--you can leave assets to *anyone* you choose. It is true that it is often easier for disgruntled relatives, who think they should have received more, to challenge bequests to a caregiver on the grounds that the caregiver used his/her position of influence to essentially override your will (your intentions or desires) and cause you to leave them something, but if a challenge is made, the court will look at the circumstances. E.g. leaving someone who cared for you for 10 days $10,000 or $20,000--not likely to be seen as the produce of "undue influence" or "duress." Leaving someone who was with you for a year or less $100,000--could easily be seen as the result of coercion of one kind or another. Try to be reasonable in what you leave; and you can include a factual receitatal in the will to bolster and explain it (e.g. "John Doe has been my live-in caregiver for the last five years and he took care of me when I could not take care of myself. For that I reason, I leave him....")