Oh, I just noticed your son is going for a Masters degree, sorry, I just assumed Ph.D. mea culpa.
I have to agree with @sybbie719, my teacher colleagues have to maintain their continuing education units for their California credentials, so they all earn their masters’ degrees while accruing units. The pay scales are based on the numbers of units accrued after the Bachelor’s degree.
Since he’s earned his degree OOS, he may be required to take additional state coursework to earn a California teacher credential.
http://www.ctc.ca.gov/credentials/out-of-state-high-sch.html