Legal Question in Wills and Trusts in California

Yup

If the account is held in joint tenancy, then typically no because ownership automatically passes to you and it is not subject to probate.

I agree that if the account was held in joint tenancy with rights of survivorship, then no, you don't need to include it in the estate's inventory and appraisal. However, I would urge to look at the intent of this joint account. Did your father simply add you to the account so that you could make payments on his behalf? Was it truly a joint account in which you both invested, made deposits and withdrawals or generally equally participated in whatever type of account (checking, savings, money market etc.) it is? It is not uncommon for an elderly parent to add his child as a signer on the account to assist the parent with bill paying and money management. But, if there were direct deposits from, for example, a pension or investment, then these funds may belong to the estate.

I would urge to speak with an estate attorney about this. You can email me at [email protected] if you have further questions.