Access forms available from the Assessor's office, including benefits, business personal property, change in ownership, and other general forms. To set up a new business account to file your Business Property Statement, please call (925) 313-7600 for more information.Community Supports (CS) are services for Medi-Cal members that address social determinants of health (SDOH). If the claim involves damage to personal property, you must submit receipts for all damaged items. Lock Out Tag Out Template (docx). Any such changes will be announced in a published addendum. Highways 4 and 160, in eastern Contra Costa County. Due dates and deadlines are the same throughout Contra Costa County when it comes to property tax. Clara County (sponsor), Contra Costa. Diablo region of Contra Costa.