California Code, Education Code - EDC § 35542

(a) Whenever the boundaries of an elementary school district and a high school district become coterminous, the districts are merged into a new unified district.

(b) Notwithstanding subdivision (a), an elementary school district that has boundaries that are totally within a high school district may be excluded from an action to unify those districts if the governing board receives approval for an exclusion from the county committee if the conditions of subdivision (b) of Section 35710 are met or from the state board if those conditions are not met. Any elementary school district so authorized to be excluded from an action to unify may continue to feed into the coterminous high school under the same terms that existed before any action to unify pursuant to subdivision (a).