Cal. Gov. Code § 21155
If the board requests a person to submit to a medical examination, he or she shall be entitled to reimbursement for expenses of transportation, and meals and lodging incident to the examination if he or she is required to travel more than 50 miles one way. Standard per diem rates in effect for state employees as authorized by current law shall be used for the reimbursement; provided, that higher costs of lodging may be paid if supported by receipt and determined necessary by the board. "Expenses of transportation" with respect to the use of private transportation includes mileage fees from the person's home to the place of examination and back to a maximum of 300 miles round trip or within the state at the appropriate current rate per mile authorized to state employees for use of private vehicles in accordance with current law plus bridge tolls. The per diem and mileage may be paid to the person by this system at the time he or she is given notification of the time and place of examination.
Ca. Gov. Code § 21155