Cal. Prob. Code § 2613

Whenever any property of the ward or conservatee is discovered that was not included in the inventory, or whenever any other property is received by the ward or conservatee or by the guardian or conservator on behalf of the ward or conservatee (other than by the actions of the guardian or conservator in the investment and management of the estate), the guardian or conservator shall file a supplemental inventory and appraisal for that property and like proceedings shall be followed with respect thereto as in the case of an original inventory, but the appraisal shall be made as of the date the property was so discovered or received.