California Code, Labor Code - LAB § 4651.1

Where a petition is filed with the appeals board concerning a continuing award of such appeals board, in which it is alleged that the disability has decreased or terminated, there shall be a rebuttable presumption that such temporary disability continues for at least one week following the filing of such petition. In such case, payment for such week shall be made in accordance with the provisions of Sections 4650 and 4651 of this code.

Where the employee has returned to work at or prior to the date of such filing, however, no such presumption shall apply.

Service of a copy of such petition on the employee shall be made as provided by Section 5316 of this code.