On most Defense Logistics Agency buys, the first sourcing question is which suppliers are allowed to supply the part, and only then which is cheapest. In an analysis of open DIBBS solicitations in September 2026, about 72% of the parts named were restricted to approved sources and only about 24% were openly competable. Roughly a quarter of the parts had exactly one approved supplier (CLEATUS, vendor analysis of open solicitations).
For a reseller, that changes the job. Sourcing a DIBBS line usually means finding the approved manufacturer or one of its authorized distributors, getting a quote that documents the chain, and keeping that document. This guide covers how to read the restriction, where to find the approved source, how a reseller quotes an approved-source part, and when a Source Approval Request makes sense. It is part of our guide to sourcing supplier quotes for a government solicitation; a short definition is in what an approved source on DIBBS is.
This guide describes DLA's published requirements and their effect on sourcing. It is not legal advice; the solicitation and its procurement notes govern each buy.
What is an approved source on DIBBS?
A manufacturer that DLA has recorded as cleared to supply a specific National Stock Number, identified by its CAGE code and its own part number. Each NSN carries a list of approved sources. When an item is marked approved source only, DLA will not accept a quote for any other manufacturer's product, however it is priced.
The restriction exists because DLA does not hold complete technical data for many parts. Where the design is controlled by an original manufacturer, or the government lacks rights to the drawings, DLA buys the part from the sources that have been qualified to make it. Where the government holds complete technical data, the part is openly competable and the approved-source list is a record of who has supplied it before rather than a gate.
How do you tell whether an NSN is open to you?
Read the acquisition method suffix code, which tells you whether the government can buy the part competitively. The codes are defined in DFARS PGI 217.7506; the ones a reseller meets most often are these.
| Code | Meaning | What it means for a reseller |
|---|---|---|
| AMSC B | Source controlled: only the approved sources may supply | Quote the approved source's product, from it or its authorized distributor |
| AMSC C | Source restricted: the design is controlled; only qualified sources | Same as B |
| AMSC D | Buy by CAGE code and part number; data not available to compete | Same as B; the named part number is the requirement |
| AMSC G | Government holds complete technical data; no restrictions | Openly competable; any capable manufacturer may be offered |
| AMSC T | Qualified products list procedures apply | Only products on the qualified products list |
Source approval is a separate route that DLA reserves for codes B, C and D; parts coded G are already full and open and are not evaluated for source approval (DLA Source Approval Request guide).
The code decides the sourcing approach before any supplier is contacted. On a G-coded part, any capable manufacturer's product can be quoted and price competition is real. On a B, C or D part, the field is the approved source and its distribution, and where there is a single approved source that sells directly, there may be no room for a reseller at all.
Where do you find the approved source for an NSN?
In the solicitation first. DIBBS requests for quotation list the approved sources for the item by CAGE code and part number, and the solicitation states when approved sources are required. Each line is a separate contract line item, explained in what a CLIN is. DLA also publishes NSN data through its public logistics information service, which lets you look up an NSN's approved CAGE codes and part numbers before a solicitation appears.
From the CAGE code, identify the manufacturer, then ask the manufacturer for its authorized distributors for that part. Many manufacturers sell to resellers only through distributors; a few sell directly. Approaching the manufacturer first tells you which route exists and gives you the distributor names that will let your quote be documented.
Where the approved source is a single manufacturer that quotes DLA directly and has no distribution, the reseller's price will include a margin on top of a competitor's direct price. That is usually a line to pass on.
How does a reseller quote an approved-source part?
By offering the approved source's product, identified by the approved part number, and holding documents that trace it back to that source. DLA's Procurement Note C03 sets out the requirement: a vendor that is not an authorized dealer or distributor for the approved source, and that does not have the item in stock, must obtain and keep a verifiable quote or item authorization letter from the approved source or its authorized distributor. The quote must be on the letterhead of the approved source or authorized distributor and include the part number, with enough detail to show that the item quoted is the item the government needs (DLAD Procurement Notes).
That makes the supplier's quote a compliance document as well as a price. A quote from an unknown broker with no letterhead, no manufacturer and no part number cannot support an approved-source line, whatever its price.
For some federal supply classes managed by DLA Land and Maritime, distributors can join the Qualified Suppliers List of Distributors. A QSLD supplier quoting on DIBBS selects the dealer option for qualified product only when full traceability for the product is available (DLA QSLD criteria).
What should the supplier's quote show?
Everything the traceability requirement asks for, so the quote you receive is the first document in the chain. Procurement Note C03 requires traceability documentation to include, at a minimum, a basic item description, the part number or NSN, the manufacturing source, the manufacturing source's CAGE code, and the name and location of every supply chain intermediary between the manufacturer and the government, and requires the contractor to keep it for six years after final payment.
| Field on the supplier quote | Why it is needed |
|---|---|
| Letterhead of the approved source or authorized distributor | Required for a verifiable quote under C03 |
| Approved part number and NSN | Shows the quoted item is the item DLA needs |
| Manufacturer and its CAGE code | Identifies the manufacturing source |
| Statement of the distributor's authorization | Shows the chain from manufacturer to distributor |
| Quantity, unit price, lead time and validity | Needed to price and deliver the line |
| Country of manufacture | Needed where the solicitation carries origin clauses |
Ask for all of this in the original request rather than after award. Asking afterwards costs a round trip, and a distributor that cannot provide it is better found before the bid than after. Keeping each request and quote filed by solicitation and line, rather than in an inbox, is what makes them retrievable for six years. The checks to run on a distributor you have not used before are in how to verify a supplier online.
When should you file a Source Approval Request instead?
When you, or a manufacturer you work with, can make the part and want to become an approved source, not when you want to resell it. A Source Approval Request is a package from a prospective new supplier containing the technical data needed to show it can manufacture the NSN to the same or better quality than the current approved sources. It applies only to NSNs bought other than full and open, coded AMSC B, C or D.
For a reseller, a Source Approval Request is rarely the right tool, because it demonstrates manufacturing competence that a reseller does not have. It becomes relevant when a small manufacturer you supply from could qualify for parts it already makes for commercial customers, which can open lines to both of you. CLEATUS, summarizing advice it attributes to DLA's small business office, suggests that filing source approval for parts with few or no approved sources is a better use of a manufacturer's effort than quoting restricted parts it cannot win.
Which DIBBS lines are worth a reseller's time?
The openly competable lines, and the approved-source lines where you can buy from an authorized distributor at a price that leaves room. Lines with a single approved source that sells directly to DLA, with no distributor in between, usually are not. Roughly a quarter of the parts in the CLEATUS analysis had exactly one approved supplier, so this case comes up often.
Sort an incoming DIBBS solicitation by code before sourcing anything. G-coded lines go to normal competitive sourcing among capable manufacturers. B, C and D lines go to the approved source's distribution, with a quick check of whether a distributor exists and will provide a verifiable quote. Lines where neither applies are the ones to pass on, which saves the supplier requests that would have gone unanswered or come back unusable. The general reasons suppliers do not answer are covered in why RFQs don't get answered on time.
FAQ
What is an approved source on DIBBS?
A manufacturer DLA has recorded as cleared to supply a specific NSN, identified by CAGE code and part number. When an item is marked approved source only, DLA will not accept a quote for any other manufacturer's product. A reseller can still quote the approved source's product, sourced from that manufacturer or its authorized distributor, with documents tracing it back.
How do I find the approved source for an NSN?
The DIBBS request for quotation lists the approved sources by CAGE code and part number. DLA's public logistics information service also shows an NSN's approved CAGE codes and part numbers. From the CAGE code, identify the manufacturer and ask it for its authorized distributors for the part.
Can a distributor quote an approved-source part on DIBBS?
Yes, if it offers the approved source's product and can document the chain. Under DLA Procurement Note C03, a vendor that is not an authorized distributor and does not have the item in stock must hold a verifiable quote or item authorization letter from the approved source or its authorized distributor, on letterhead, with the part number, and keep traceability records for six years after final payment.
What do AMSC codes mean?
Acquisition method suffix codes, defined in DFARS PGI 217.7506, say whether a part can be bought competitively. B, C and D mean the part is restricted to approved sources or a named part number; G means the government holds complete technical data and the part is openly competable; T means qualified products list procedures apply.
Should a reseller file a Source Approval Request?
Usually not. A Source Approval Request demonstrates the competence to manufacture the part and applies to parts coded AMSC B, C or D. It makes sense for a manufacturer, including a small manufacturer a reseller works with, not for a reseller quoting another company's product.
Key takeaways
- About 72% of parts on open DIBBS solicitations in September 2026 were restricted to approved sources, about 24% were openly competable, and roughly a quarter had a single approved supplier (CLEATUS, vendor analysis).
- Read the acquisition method suffix code first: B, C and D restrict the part to approved sources or a named part number; G is openly competable; T requires a qualified product.
- The solicitation lists the approved CAGE codes and part numbers; from there, ask the manufacturer for its authorized distributors.
- A reseller quoting an approved-source part needs a verifiable quote or authorization letter from the approved source or its authorized distributor, on letterhead, with the part number (DLA Procurement Note C03).
- Ask for letterhead, part number, manufacturer, CAGE code, the distributor's authorization and country of manufacture in the original request, and keep the records for six years after final payment.
- Source Approval Requests are for manufacturers. A reseller's better filter is to pass on single-source lines with no distribution.