If a claim for entitlement to compensation or additional compensation under chapter 11 of this title or pension or additional pension under chapter 15 of this title is pending at the time of a veteran’s death and the check or other payment issued to the veteran’s surviving spouse under subsection (a) is less than the amount of the benefit the veteran would have been entitled to for the month of death pursuant to the adjudication of the pending claim, an amount equal to the difference between the amount to which the veteran would have been entitled to receive under chapter 11 or 15 of this title for the month of the veteran’s death had the veteran not died and the amount of the check or other payment issued to the surviving spouse shall be treated in the same manner as an accrued benefit under section 5121 of this title.