Welf. & Inst. Code, § 6601.3

(a) Upon a showing of good cause, the Board of Parole Hearings may order that a person referred to the State Department of State Hospitals pursuant to subdivision (b) of Section 6601 remain in custody for no more than 45 days beyond the person’s scheduled release date for full evaluation pursuant to subdivisions (c) to (i), inclusive, of Section 6601.

(b) For purposes of this section, good cause means circumstances where there is a recalculation of credits or a restoration of denied or lost credits by any custodial agency or court, a resentencing by a court, the receipt of the prisoner into custody, or equivalent exigent circumstances that result in there being less than 45 days prior to the person’s scheduled release date for the full evaluation described in subdivisions (c) to (i), inclusive, of Section 6601.