Notes from https://www.barrons.com/amp/articles/inheritance-tax-charity-donation-mistake-37f90b04
Stocks, real property, collectibles, businesses, and cryptocurrencies, are stepped up to their value on the day of the owner’s death.
retirement accounts and tax-deferred annuities, aren’t stepped up in value.
If you want to give some assets to charity, you should first donate the assets that don’t get stepped up in value at your death.
Parents can avoid probate and retain step-up for their heirs by creating a revocable trust for their real estate
Upon death, the trustees—presumably the children—can take control of the house without going through probate, but they won’t owe taxes on its previous capital gain.
They will, however, need to get the home appraised to establish its value at the “date of demise.”