38 CFR 70.32: Reimbursement or prior payment.

(a) Payment will be made on a reimbursement basis after the travel has occurred, except that:

(1) Upon completion of examination, treatment, or care, payment may be made before the return travel has occurred, and

(2) In the case of travel by a person to or from a VA facility by special mode of transportation, VA may provide payment for beneficiary travel to the provider of the transportation before determining eligibility of such person for such payment if VA determines that the travel is for emergency treatment and the beneficiary or other person made a claim that the beneficiary is eligible for payment for the travel.

(b) Payment under this part will be made to the beneficiary, except that VA may make a beneficiary travel payment under this part to a person or organization other than the beneficiary upon satisfactory evidence that the person or organization actually provided or paid for the travel.