my son is getting out of usmc if he claims disability for ptsd is he or the va required to release that information when applying for a civilian or

He is not required to disclose any medical information to a prospective employer.  This is especially the case if the disability would have no direct bearing on his ability to perform the job.  As an example, if he had a back injury that limited him from lifting anything over 10 pounds, he may have to inform the employer of this if the job he applied for was on the loading dock and frequently required lifting over 10 pounds. At some point in the future, he may need an accommodation for his PTSD if it interferes with his work duties.  But until then, he need not disclose this