health condition. (D) The number of total claims for disability compensation and pension submitted, approved, and disapproved for each group of veterans. (3) An identification of common barriers for members of the National Guard and members of reserve components in obtaining disability benefits under the laws administered by the Secretary of Veterans Affairs, including barriers relating to documentation of injuries incurred while serving, such as line of duty letters. (b) Reports (1) Preliminary report Not later than 18 months after the date of the enactment of this Act, the Comptroller General shall submit to the Committees on Veterans’ Affairs of the Senate and House of Representatives a preliminary report on the findings of the study required by subsection (a). (2) Final report Upon completion of the study, the Comptroller General shall submit to such Committees a final report on such study.