Legal Question in Health Care Law in California

Persons can lawfully obtain an orchiectomy as part of a gender change operation, so I'm not aware that any law would prohibit your merely wanting to have yourself neutered. But you would have to locate a provider willing to perform such a procedure, and any provider that would offer the procedure might well advise you to have a vasectomy instead, and might well suggest or require a psych consult. Consult your family physician.