In fixing a term under this section, the board shall utilize the upper term of imprisonment which could have been imposed for the offense or offenses of which the person was convicted, increased by any additional terms which could have been imposed based on matters which were found to be true in the committing court. However, if at least two of the members of the board after reviewing the person's file determine that a longer term should be imposed for the reasons specified in Section 1170.2, a longer term may be imposed following the procedures and guidelines set forth in Section 1170.2, except that any hearings deemed necessary by the board shall be held within 90 days of September 28, 1979. Within 90 days of the date the person is received by the state hospital or other treatment facility, or of September 28, 1979, whichever is later, the Board of Prison Terms shall provide each person with the determination of the person's maximum term of commitment or shall notify the person that a hearing will be scheduled to determine the term.
Within 20 days following the determination of the maximum term of commitment the board shall provide the person, the prosecuting attorney, the committing court, and the state hospital or other treatment facility with a written statement setting forth the maximum term of commitment, the calculations, and any materials considered in determining the maximum term.
Ca. Pen. Code § 1026.5