38 CFR § 3.402 - Surviving spouse.
Awards of pension, compensation, or dependency and indemnity compensation to or for a surviving spouse will be effective as follows:
(a) Additional allowance of dependency and indemnity compensation for children § 3.5(e). Commencing date of surviving spouse's award. See § 3.400(c).
(b) Legal surviving spouse entitled. See § 3.657.
(c) Aid and attendance and housebound benefits.
(1) Date of receipt of claim or date entitlement arose whichever is later. However, when an award of dependency and indemnity compensation (DIC) or pension based on an original or supplemental claim is effective for a period prior to date of receipt of the claim, any additional DIC or pension payable to the surviving spouse by reason of need for aid and attendance or housebound status shall also be awarded for any part of the award's retroactive period for which entitlement to the additional benefit is established.
(2) Date of departure from hospital, institutional or domiciliary care at Department of Veterans Affairs expense. This is applicable only to aid and attendance benefits. Housebound benefits may be awarded during hospitalization at Department of Veterans Affairs expense.