Mode/Method of Shipment Codes — Complete Reference

Mode/Method of Shipment Codes — the Defense Transportation Regulation calls them Transportation Mode/Method Codes — are one-character alphanumeric codes that answer the question on every open requisition once the materiel finally moves: how is it coming? The code identifies the general mode (air or surface) and the specific method (motor, rail, air freight, parcel post) used for each segment of movement within the Defense Transportation System (DTS). The shipper selects the code, and the customer sees it in record position 77 of MILSTRIP shipment status (DIC AS_/AU_) and materiel release confirmation transactions — the same messages that carry the ship date and the shipment hold code when movement stalls.

At a glance

• What it is: A one-position alpha/numeric code identifying the manner of movement — mode and method — for a shipment segment in the DTS.
• Assigned by: The shipper, based on how the shipment actually moves.
• Where it rides: Record position 77 of shipment status and materiel release confirmation transactions; also part of the transportation documentation family alongside the TCMD.
• Governing publication: DTR 4500.9-R, Part II (Cargo Movement); the supply-transaction formats that carry it are DLM 4000.25, Volume 2.
• Reading old paper? Several letters were reused when the DTR superseded MILSTAMP — see the legacy-meanings note below the table.

Complete code table

Legacy letter reuse. When the DTR superseded MILSTAMP, several letters were reassigned. In the older set — which some Service publications still reproduce, including NAVSUP P-485's appendix of DTR codes — L was rail less-than-carload, N was LOGAIR, R was the European/Pacific Distribution System, and Y was military intra-theater airlift. On documents or systems of that vintage, verify which set applies before interpreting the letter.

How the code is used

• Telling the customer how it's coming. The mode code arrives with the shipment status: F or O means the shipment is in military airlift channels and will surface at an aerial port; G/H/6/7 mean it is in the mail stream and there is no carrier to call; A/B/S mean commercial trucking against the delivery standards for the priority.
• In-transit visibility and follow-ups. The mode determines what tracking exists. A TGBL or commercial move has carrier documentation; parcel post has postal tracking at best; and Mode X (bearer walk-through/customer pickup) has no transit segment at all — under DLMS procedures it carries no in-transit tracking requirement, because custody passed at the point of issue.
• Transportation documentation. Mode/method coding is part of the DTS documentation family: the Transportation Control and Movement Document (TCMD) describes and controls the movement the mode code summarizes, keyed by the Transportation Control Number.
• Segment-by-segment description. A single requisition's materiel can move under different modes per segment — truck to the aerial port (A), AMC channel across the ocean (F), local delivery at destination (9); the code describes the segment being reported.

Worked example

A shipment status transaction arrives for an overseas requisition: ship date yesterday, Mode of Shipment F — AMC channel airlift. The customer knows to watch the aerial port's arrivals, not a commercial carrier's tracking page, and to expect movement per the airlift channel schedule. A week later a second line ships Mode G (surface parcel post): that one is in the military postal system, no carrier tracking, and the delivery standard is measured in weeks, not days. Same requisition number, two segments, two entirely different places to look when someone asks "where's my part?"

Common errors and gotchas

• Reading a modern letter with a legacy meaning (or vice versa). L, N, R, U, and Y changed meaning between MILSTAMP and the current DTR — and stale reproductions circulate, including in current-revision Service manuals. Confirm which code set your document's vintage uses.
• Confusing the mode code with the hold code. Both ride shipment status transactions: the mode code (rp 77) says how the shipment moves; the shipment hold code (rp 51) says why it hasn't. Neither substitutes for the other.
• Expecting carrier tracking on postal and organic modes. Codes G, H, 6, and 7 are mail; O and F are military lift; X never entered transportation at all. Follow-up channels differ for each.
• Treating the code as the whole routing. It describes one movement segment, not the door-to-door itinerary. Multi-segment moves are documented on the TCMD under a single Transportation Control Number.
• Assuming every character is assignable. The set is A–Z plus 1–9 as listed; there is no code 0, and unlisted characters are not valid entries.

Related codes and cross-references

• Transportation Control and Movement Document (TCMD) — the DTS documentation for the movement the mode code summarizes.
• Shipment Hold Codes — the delay-reason companion in the same shipment status transactions (rp 51).
• Document Identifier Codes (DIC) — AS_/AU_ shipment status and materiel release confirmation transactions carry the mode code in rp 77.
• Supply Status Codes — the supply-side status that precedes shipment; once materiel moves, the mode code takes over the story.
• Media and Status Codes — determine which activities receive the shipment status transactions carrying the mode code.

Authoritative references

• DTR 4500.9-R — Defense Transportation Regulation, Part II (Cargo Movement). The governing publication for transportation mode/method codes. The current edition no longer prints the code table in an appendix — Appendix Y designates the USTRANSCOM Reference Data Management (TRDM) process as the managed distribution point for the tables.
• USTRANSCOM TRDM — Transportation Method Code table. The authoritative current code list, published on USTRANSCOM's public Defense Transportation Electronic Business (DTEB) reference-data pages.
• DLA Customer Assistance Handbook (print edition, December 2023). DLA's public customer reference reproducing the DTR mode/method of shipment code table (record position 77).
• DLM 4000.25, Volume 2 — Supply Standards and Procedures. The MILSTRIP/DLMS transaction formats that carry the mode of shipment in shipment status and materiel release confirmation.
• NAVSUP P-485, Volume II (Revision 9, April 2026), Appendix 5, Part F. The Navy reproduction of DTR codes — note it carries several legacy MILSTAMP-era letter meanings.

Last verified

This reference was last reviewed on 2026-07-08. All 35 codes were verified against the USTRANSCOM TRDM Transportation Method Code reference table — the authoritative current distribution of the DTR code set, published on USTRANSCOM's public DTEB reference-data pages and designated by the current DTR Part II (May 2026 edition), Appendix Y. Placement (rp 77) and the Mode X no-tracking rule were verified against DLM 4000.25, Volume 2 (April 2026 edition, in hand), with the DLA Customer Assistance Handbook (December 2023) and the 1999 DTR Part II edition as corroborating sources. Where Service manuals reproduce older MILSTAMP-era letter meanings (notably NAVSUP P-485 Appendix 5F), the discrepancy is flagged in the text rather than silently resolved. To suggest a correction, use the site's correction path.