37 U.S. Code § 452 - Allowable travel and transportation: general authorities
(a) In General.— Except as otherwise prohibited by law, a member of the uniformed services or other authorized traveler may be provided transportation-, lodging-, or meals-in-kind, or actual and necessary expenses of travel and transportation, for, or in connection with, official travel under circumstances as specified in regulations prescribed under section 464 of this title.
(b) Specific Circumstances.— The authority under subsection (a) includes travel under or in connection with, but not limited to, the following circumstances, to the extent specified in regulations prescribed under section 464 of this title:
(1) Temporary duty that requires travel between a permanent duty assignment location and another authorized temporary duty location, and travel in or around the temporary duty location.
(2) Permanent change of station that requires travel between an old and new temporary or permanent duty assignment location or other authorized location.
(3) Temporary duty or assignment relocation related to consecutive overseas tours or in-place-consecutive overseas tours.
(9) Reserve component inactive-duty training performed outside the normal commuting distance of the member’s permanent residence.
(12) Presence of family members at a military medical facility incident to the illness or injury of members.
(14) Presence of non-medical attendants for very seriously or seriously wounded, ill, or injured members.
(16) Missing status, as determined by the Secretary concerned under chapter 10 of this title.
(c) Matters Included.— Travel and transportation allowances which may be provided under subsection (a) include the following:
(2) Dislocation or relocation allowances paid in connection with a change in a member’s temporary or permanent duty assignment location.
(d) Mode of Providing Travel and Transportation Allowances.— Any authorized travel and transportation may be provided—
(e) Travel and Transportation Allowances When Travel Orders Are Modified, etc.— An authorized traveler whose travel and transportation order or authorization is canceled, revoked, or modified may be allowed actual and necessary expenses or travel and transportation allowances in connection with travel performed pursuant to such order or authorization.
(f) Advance Payments.— An authorized traveler may be allowed advance payments for authorized travel and transportation allowances.
(g) Responsibility for Unauthorized Expenses.— Any unauthorized travel or transportation expense is not the responsibility of the United States.