California Code, Military and Veterans Code - MVC § 256

(a) An enlisted member of the California National Guard who has served 20 years in the active service of the state may, on application, in the discretion of the Governor, be retired.  Service in the United States Army, United States Air Force, United States Navy, or any reserve component thereof shall be considered as state service in computing length of state service for the purposes of this section.

(b) Upon application made within one year of retirement, the person may, in the discretion of the Governor, be granted an honorary advancement to the next rank above that held on the date of application for retirement.  The Adjutant General shall adopt regulations governing the application procedure, qualifications required, and rights and privileges in connection with honorary post-retirement promotions.  If recalled to either state or federal active service, a person honorarily promoted under this subdivision shall return to duty in that rank specified by federal law or regulations applicable to the person.

(c) An enlisted member on active duty with the office of the Adjutant General pursuant to Section 167 who is not a member of the Public Employees' Retirement System and who has been on active duty with the office of the Adjutant General for a total of 10 years shall, on application, be retired in accordance with the federal law and regulations which on the date of application govern the retirement of enlisted members of the reserve components of the Army of the United States on extended active duty.  In these cases, the length of service shall be computed as provided in this section and Section 215.