Sale of House-gift transfer or inherited?

[Randall]

If an aging parent transfers home to child while living, but the document specifies parent can live there until death, does the house not really transfer until death?  Inherited stepped up basis?  I keep hearing this but I don't know where to look for reference.

[Abby Normal]

https://www.thetaxadviser.com/issues/2007/nov/giftingofaremainderinterestinahome.html

[DANRVAN]

8 hours ago, Randall said:

but the document specifies parent can live there until death

Even without a written agreement, there is an implied life estate held by case law.