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:
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.
Permanent change of station that requires travel between an old and new temporary or permanent duty assignment location or other authorized location.
Temporary duty or assignment relocation related to consecutive overseas tours or in-place-consecutive overseas tours.
Recruiting duties for the armed forces.
Assignment or detail to another Government department or agency.
Rest and recuperative leave.
Convalescent leave.
Reenlistment leave.
Reserve component inactive-duty training performed outside the normal commuting distance of the member’s permanent residence.
Ready Reserve muster duty.
Unusual, extraordinary, hardship, or emergency circumstances.
Presence of family members at a military medical facility incident to the illness or injury of members.
Presence of family members at the repatriation of members held captive.
Presence of non-medical attendants for very seriously or seriously wounded, ill, or injured members.
Attendance at Yellow Ribbon Reintegration Program events.
Missing status, as determined by the Secretary concerned under chapter 10 of this title.
Attendance at or participation in international sports competitions described under section 717 of title 10.
(c) Matters Included.—Travel and transportation allowances which may be provided under subsection (a) include the following:
Allowances for transportation, lodging, and meals.
Dislocation or relocation allowances paid in connection with a change in a member’s temporary or permanent duty assignment location.
A partial dislocation allowance paid to a member ordered to occupy or vacate housing provided by the United States.
Other related miscellaneous expenses.
(d) Mode of Providing Travel and Transportation Allowances.—Any authorized travel and transportation may be provided—
as an actual expense;
as an authorized allowance;
in-kind; or
using a combination of the authorities under paragraphs (1), (2), and (3).
(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.
(h) Relationship to Other Authorities.—
The administering Secretary may not provide payment under this section for an expense for which payment may be provided from any other appropriate Government or non-Government entity.

2019—Subsec. (c)(3), (4). Pub. L. 116–92 added par. (3) and redesignated former par. (3) as (4).