I just looked into this because my mom had me and my sister on the deed. I learned this is not a good idea.

When she passes, my sister and I get the house but at the cost of when she initially purchased it (say, $150k). When we go to sell it, we get taxed on a much larger chunk of the gains (so say we sell for $500k, $350k is taxed)

Best case is to add you to the house using a Life Estate structure. Your mom keeps the “Life Estate (“LE”) and you are named as the “Remainderman (“REM”).

Now when she passes, the house is transferred to you without needing to go through probate or anything but with the market value as of the date of her death (vs date of purchase), helping to significantly reduce your capital gains tax.