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AMSC Codes — Acquisition Method Suffix Codes

AMSC (Acquisition Method Suffix Code) is a single-letter code that appears on every DLA spare-parts solicitation. It tells bidders how a part can be acquired — whether the procurement is full and open competition, restricted to approved sources, sole source, or under interim review pending data-rights resolution. There are 20 active AMSC letters; the remaining letters are reserved or not authorized.

Full and open

G, Z

Open competition — any qualified manufacturer can bid.

Limited competition

A, H, K, L, M, N, Q, T, U

Multiple sources may qualify, but technical or process restrictions apply.

Restricted source

B, C, D, P, R, S, V, Y

New bidders typically must submit a Source Approval Request.

Reserved / not used

E, F, I, J, O, W, X

Reserved for future use, never screened, or not authorized.

Full AMSC code reference (A–Z)

Each row covers the verbatim meaning of the code, what it implies for competition, and which AMC numeric codes are valid pairings. Click a letter to jump.

AMSC A

Data rights questionable (interim)

Limited competition

The Government's right to use data in its possession is questionable. Temporary code applied during data-rights review.

Assigned only at the conclusion of limited screening for parts under immediate buy requirements. Remains assigned until full screening resolves the Government's data rights and the part is recoded to a different AMSC. If one source is available, AMC 3, 4, or 5 are valid; if at least two sources exist (or data is adequate for an alternate to qualify), AMC 1 or 2 are valid.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC B

Source-controlled item

Restricted source

Must be acquired from a source specified on a source control or selected item drawing.

Suitable technical data, Government data rights, or manufacturing knowledge are not available to permit acquisition from other sources, qualification testing of an alternate, or use of a second-source part in the intended application. To become an approved source, contractors typically submit a Source Approval Request (SAR) — and AMSC B parts may require additional documentation from the source-controlling holder demonstrating that permission has been granted to use their technical data.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC C

Engineering source approval required

Restricted source

Requires engineering source approval by the design control activity to maintain part quality.

Existing unique design capability, engineering skills, and manufacturing knowledge held by the qualified source(s) require acquisition from approved sources. The approved source(s) retain data rights, manufacturing knowledge, or technical data not economically available to the Government. Alternate sources must qualify in accordance with the design control activity's procedures.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC D

CAGE & part number

Restricted source

Data needed to acquire competitively is not physically available, cannot be obtained economically, and adequate specifications cannot be drafted.

Procurement is restricted to a specific manufacturer's CAGE code and part number combination. The Government does not possess sufficient data to write a competitive specification, and reverse engineering or specification development is not economical. Only AMC 3, 4, or 5 are valid.

Valid AMC pairings: 3, 4, 5

AMSC E

Reserved

Reserved

Reserved for future use.

Reserved by 48 CFR Ch. 2 App. E §201.2. Not currently assigned to any procurement action.

AMSC F

Reserved

Reserved

Reserved for future use.

Reserved by 48 CFR Ch. 2 App. E §201.2. Not currently assigned to any procurement action.

AMSC G

Full and open competition

Full and open

The Government has rights to the technical data, the data package is complete, and there are no technical, engineering, tooling, or manufacturing restrictions.

The only AMSC that implies full and open competition. The Government owns adequate technical data and data rights for any qualified manufacturer to bid. Other AMSCs (such as K, M, N, Q, S) may imply limited competition when two or more sources exist but the technical data package is inadequate for full and open competition.

Valid AMC pairings: 1, 2

AMSC H

Insufficient physical data (interim)

Limited competition

The Government does not physically have sufficient, accurate, or legible data to purchase from other than current source(s).

Temporary code applied to parts under immediate buy requirements while the data deficiency is under review. Assigned only at the conclusion of limited screening; remains until full screening resolves the data question and a different AMSC is assigned.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC I

Not authorized

Not authorized

Not authorized for use.

AMSC I is not authorized for assignment under 48 CFR Ch. 2 App. E §201.2.

AMSC J

Reserved

Reserved

Reserved for future use.

Reserved by 48 CFR Ch. 2 App. E §201.2. Not currently assigned to any procurement action.

AMSC K

Class 1 castings or similar forgings

Limited competition

Part must be produced from class 1 castings and similar forgings controlled per MIL-STD-2175.

Repetitive controlled-source production is required. If only one source has acceptable castings/forgings and cannot provide them to others, AMC 3, 4, or 5 are valid; if two or more sources have such castings (or they can be provided to others), AMC 1 or 2 are valid.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC L

Below screening threshold

Limited competition

Annual buy value falls below the screening threshold established by DoD components.

Used only to replace AMSC O for parts under the established screening threshold. The part has been screened for additional known sources, but no further screening has been performed to determine competitive conditions that would warrant a different AMSC.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC M

Master or coordinated tooling

Limited competition

Manufacture requires master or coordinated tooling that is not available to other sources.

If only one set of tooling exists and cannot be made available to another source, AMC 3, 4, or 5 are valid. If existing or refurbishable tooling is available to two or more sources, AMC 1 or 2 are valid.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC N

Special test or inspection facilities

Limited competition

Manufacture requires special test or inspection facilities to maintain ultra-precision quality.

Substantiation and inspection of precision or quality cannot be accomplished without specialized facilities. If facilities cannot be made available for competitive manufacture, AMC 3, 4, or 5 are valid; if they can be made available to two or more sources, AMC 1 or 2 are valid.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC O

Never screened

No screening

Part was not assigned an AMSC when it entered the inventory and has never completed screening.

Used in conjunction with AMC 0. Use is discouraged — maximum effort should be made to determine an applicable alternate AMSC. Only AMC 0 is valid.

Valid AMC pairings: 0

AMSC P

Data rights not owned by Government

Restricted source

Rights to use the data are not owned by the Government and cannot be purchased, developed, or otherwise obtained. Uneconomical to reverse engineer.

Used when the Government has the technical data but does not own the rights to use it for additional procurement. If only one source has the rights or data, AMC 3, 4, or 5 are valid; if two or more sources have rights, AMC 1 or 2 are valid.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC Q

Inadequate data — pending breakout

Limited competition

The Government lacks adequate data and/or rights, has been unable to economically obtain them, and the part has been undergoing full screening for 12 or more months.

Breakout to competition has not yet been achieved, but ongoing actions to obtain data rights or adequate reprocurement technical data indicate breakout is expected. May be a candidate for reverse engineering. All AMSC Q items must be reviewed within timeframes specified in §203(b).

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC R

No data, no rights, uneconomical to reverse engineer

Restricted source

The Government does not own the data or the rights, has determined it uneconomical to buy them, and uneconomical to reverse engineer.

Used when the Government did not initially purchase the data or rights. If only one source has the rights or data to manufacture the item, AMC 3, 4, or 5 are valid; if two or more sources do, AMC 1 or 2 are valid.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC S

Militarily sensitive technology

Restricted source

Acquisition is restricted to Government-approved sources because production involves unclassified but militarily sensitive technology.

Restriction is governed by FAR 6.3. If only one source is approved, AMC 3, 4, or 5 are valid; if at least two sources are approved, AMC 1 or 2 are valid.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC T

Qualified Products List (QPL)

Limited competition

Acquisition is controlled by Qualified Products List (QPL) procedures.

Competition is limited to sources listed on or qualified for listing on the QPL at the time of award (see FAR Part 9 and DFARS Part 209). Only AMC 1 or 2 are valid.

Valid AMC pairings: 1, 2

AMSC U

Breakout cost exceeds savings

Limited competition

Breakout cost has been determined to exceed projected lifetime savings.

If one source is available, AMC 3, 4, or 5 are valid; if at least two sources exist, AMC 1 or 2 are valid.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC V

High-reliability part

Restricted source

Designated a high-reliability part under a formal program; failure would be unacceptable for safety.

The cognizant engineering activity has determined that data to define and control reliability limits cannot be obtained, nor can adequate specifications be drafted. If one source is available, AMC 3, 4, or 5 are valid; if at least two sources are available, AMC 1 or 2 are valid.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC W

Reserved

Reserved

Reserved for future use.

Reserved by 48 CFR Ch. 2 App. E §201.2. Not currently assigned to any procurement action.

AMSC X

Not authorized

Not authorized

Not authorized for use.

AMSC X is not authorized for assignment under 48 CFR Ch. 2 App. E §201.2.

AMSC Y

Unstable design

Restricted source

Design is unstable; engineering, manufacturing, or performance characteristics indicate required design objectives have not been achieved.

Major changes are contemplated due to low process yield or marginal performance during tests or service use. Anticipated changes will render the present part obsolete and unusable in its current configuration; limited acquisition from the present source is expected pending configuration changes.

Valid AMC pairings: 1, 2, 3, 4, 5

AMSC Z

Commercial / off-the-shelf

Full and open

Commercial, nondevelopmental, or off-the-shelf item. Commercial item descriptions, vendor catalogs, or commercial manuals apply.

If one source is available, AMC 3, 4, or 5 are valid; if at least two sources are available, AMC 1 or 2 are valid.

Valid AMC pairings: 1, 2, 3, 4, 5

AMC codes (numeric) — 0 through 5

AMSC codes are always paired with a single-digit AMC (Acquisition Method Code) that describes the actual procurement method. The combination — for example, “1G” for competitive procurement of an unrestricted item — appears on every DLA solicitation.

AMCTitleDescription
0Not yet assignedThe part has not been assigned an AMC of 1 through 5. Used in conjunction with AMSC O when a part has never completed screening.
1Acquire competitivelyAcquire the part competitively. Used for subsequent buys after a competitive procurement has already been conducted.
2Acquire competitively (first time)Acquire the part competitively for the first time. After the first acquisition under AMC 2, the code is recoded to AMC 1.
3Acquire from actual manufacturerAcquire the part directly from the actual manufacturer. Used when the Government has determined competition is not possible but procurement should bypass the prime.
4Acquire from actual manufacturer (first time)Acquire from the actual manufacturer for the first time. After the first acquisition under AMC 4, the code is recoded to AMC 3.
5Sole source — not actual manufacturerAcquire directly from a sole-source contractor that is not the actual manufacturer (for example, a prime contractor that subcontracts the actual production).

How to read AMSC codes on a DIBBs solicitation

On the DLA Internet Bid Board System (DIBBs), the AMSC and AMC codes appear together as a two-character combination (for example, 1G or 3B) in the technical item description for the National Stock Number being solicited.

  • 1GCompetitive procurement, no restrictions. Open to any qualified bidder.
  • 2TFirst-time competitive procurement, but limited to QPL-listed sources.
  • 3BAcquire from actual manufacturer; source-controlled. Submit a SAR to qualify.
  • 5DSole-source non-manufacturer; restricted to a specific CAGE & part number.

Bidding on a restricted-source part?

Parts coded AMSC B, C, or D require new bidders to submit a Source Approval Request before they can compete. Read the full SAR process, package categories, and timeline.

View the SAR Process Guide

Frequently asked questions

  • What is an AMSC code?

    AMSC (Acquisition Method Suffix Code) is a single-letter alpha code assigned by a DoD activity that describes the engineering, manufacturing, and technical restrictions on a part. AMSC tells contracting officers and bidders how a part can be acquired — full and open competition, restricted to approved sources, sole source, or under interim review.

  • Which AMSC code allows full and open competition?

    Only AMSC G implies full and open competition. The Government has rights to the technical data, the data package is complete, and there are no engineering, tooling, or manufacturing restrictions. AMSC Z (commercial off-the-shelf items) is also broadly competitive.

  • What does AMSC B mean?

    AMSC B means the part is source-controlled — it must be acquired from a manufacturer specified on a source control or selected item drawing. To bid, contractors typically submit a Source Approval Request (SAR) and may need a permission letter from the source-controlling holder authorizing use of their technical data.

  • What is the difference between AMSC and AMC?

    AMSC is the alpha (letter) suffix code that describes data rights and restrictions. AMC is the numeric (0–5) code that describes the actual procurement method — competitive (1, 2), from the actual manufacturer (3, 4), or sole source (5). They are always used together; the combination determines bidding eligibility.

  • Which AMSC codes require a Source Approval Request?

    Source Approval Requests apply primarily to AMSC B (source-controlled), AMSC C (engineering source approval required), and AMSC D (CAGE & part number restricted). AMSC G parts are already full-and-open competition and do not require a SAR.

  • Where do AMSC codes appear?

    AMSC and AMC codes appear on every DLA spare-parts solicitation issued through the DLA Internet Bid Board System (DIBBs), as well as in the Federal Logistics Information System (FLIS) item-intelligence record for each National Stock Number (NSN).