App . 389 , 394 - 95 ( 1996 ) . Apart from the above provisions , VA revised the regulation governing adjudication of claims for service connection for PTSD , effective July 13 , 2010 . See 75 Fed . Reg . 39 , 843 ( since codified at 38 C . F . R . § 3 . 304 ( f ) ( 3 ) ) . The revised regulation essentially eases the requirement that there be corroboration of a claimed in - service stressor . Under this standard , if a stressor claimed by a Veteran is related to the Veteran ' s fear of hostile military or terrorist activity and a VA psychiatrist or psychologist confirms that the claimed stressor is adequate to support