41 CFR § 301-11.4
May I be reimbursed actual expense and per diem on the same trip?
June 9, 2020
Yes, you may be reimbursed both actual expense and per diem during a single trip, but only one method of reimbursement may be authorized for any given calendar day except as provided in §301-11.305 or §301-11.306. Your agency must determine when the transition between the reimbursement methods occurs.