California Code, Health and Safety Code - HSC § 1765.125

(a) Except as provided in subdivision (b), no person, political subdivision of the state, or governmental agency shall operate a mobile service unit without first obtaining a license or an addition to existing licensure under this chapter unless exempt from licensure under Section 1206.

(b) Any person, political subdivision of the state, or governmental agency, that was operating a mobile unit as of January 1, 1994, may continue to operate the mobile unit only under the following conditions:

(c) Notwithstanding any other provision of this chapter, after the initial licensure, or the initial approval of the addition to existing licensure of a parent facility, to operate a mobile service unit, the department shall not require that each site where the mobile unit operates be licensed or approved by the department unless the mobile unit will be operating outside of the proposed area or areas specified in the application pursuant to paragraph (4) of subdivision (b) of Section 1765.130.