The Department of Defense recently announced that effective April 7, 2022, the Joint Travel Regulations will allow nursing service members and civilian employees to be reimbursed for breast milk shipment costs when on official travel for more than three days.

https://www.af.mil/News/Article-Display/Article/3003348/wit-champions-win-for-dod-members-new-policy-authorizes-breast-milk-shipment-re/ DoD News