Legal Question in Real Estate Law in California

No, but it is often helpful to do so. Note, if it is in joint tenancy, it is not in the trust.

Your question raises more questions. The property is either in joint tenancy or in the trust. Not both. You need to determine exactly what the present title vesting is first. Talk to an attorney or a title officer. Once you can determine the present vesting, appropriate actions can be taken to place title into the proper form. The process to do so depends on present title. The prpper form of title now depends on whether title should be in trust or in some other form to comply with the existing estate plan.

It isn't clear from your question whether your dad is still living. If he has passed away, any property formerly held by your mom and dad as joint tenants would, upon his death, become your mom's sole property. A two-person joint tenancy terminates upon the death of either joint tenant. Also, in speaking about the owners of real estate, the correct expression is "on title" rather than "on the deed."

Property can be held in joint tenancy and trust, such as a joint tenancy between two trusts. It is a bizarre application, but it would help us if you were more clear on the chain of title.