Do you need to pay my Marine's bills while he/she is deployed? First of all, did your Marine specifically ask you to pay his/her bills while they were deployed? If not, then it's very possible that your Marine took advantage of the pre-deployment sessions where he/she pre-arranged for bills to be paid electronically while deployed.
In addition, Marines are given an opportunity to request an allotment from their payroll checks to have money with them while in country.
See also the "Soldiers and Sailors Act" and "Power of Attorney" (links to the right).