I had a joint spousal stock account, spouse passed, TOD to individual account and the partial share sold, how to I report cost basis on this?

[marg389153]

Surviving spouse now owns the common stock.

[AmyC]

Since the account was transferred to you, you should be receiving any tax forms related to transactions after your spouse passing. Any sales prior to passing would come in name of spouse. You can file a joint return the final year, if you did not remarry.

I am sorry for your loss.

[Hal_Al]

Half your original basis "steps up" to the fair market value (FMV) on the date of death.  Using an example, you jointly owned 100 shares of stock bought in 1999 for $1000. When your spouse passed in 2020, the stock was worth $3000.  Your new basis is $2000:  $500 (your half of the original $1000 cost) + $1500 (spouse's half of the $3000 FMV).

If you live in a community property state, the entire basis steps up to the FMV on the date of death.