SAM.gov is the single required point of entry for federal contract opportunities, but plenty of buying still happens through systems that sit beside it, not inside it. If you only ever check SAM.gov, you are missing entire categories of work that never gets posted there in the same way. Every system below is free to use, same as SAM.gov itself. Each one simply requires you to learn its quirks and check it on some kind of rhythm, and most businesses will only ever need one or two of them beyond SAM.gov.
| Portal | What it is for | Who can see it |
|---|---|---|
| eBuy | RFQs against GSA Multiple Award Schedule contracts | Only businesses holding the relevant Schedule contract |
| DIBBS | Defense Logistics Agency parts and supply buys | Open to anyone, built for a narrow slice of items |
| FedConnect | Full notice and proposal exchange some agencies use instead of, or alongside, SAM.gov | Open to anyone, registration required |
| Agency-run portals | Individual agencies managing their own opportunities separately | Varies by agency |
eBuy: Schedule holders only
eBuy is the General Services Administration's ordering system for the Multiple Award Schedule. Agencies post RFQs here, and only businesses that already hold the relevant GSA Schedule contract can see or respond to them. If you are not on the Schedule, you will never see what moves through eBuy, which is one more reason getting on the Schedule matters if that is where your market actually buys.
DIBBS: a narrow, specific world
DIBBS belongs to the Defense Logistics Agency and handles solicitations for parts, supplies, and other tangible defense items, more hardware and materiel than services. It is open to anyone, but it is built for a specific kind of buying and reads nothing like SAM.gov. If you sell parts or supplies the Defense Department buys, it is worth learning on its own terms rather than expecting it to behave like anything else here.
FedConnect and agencies that run their own doors
A number of agencies use FedConnect, or a system of their own, as the actual notice and proposal exchange, sometimes alongside a SAM.gov posting and sometimes leaving SAM.gov with only a pointer rather than the full listing. The pattern worth noticing: when an agency runs its own portal, the SAM.gov notice usually says so and links you onward. Read that fine print instead of assuming SAM.gov has the whole story.
The honest takeaway
Nobody should try to monitor five separate portals every day. Figure out which doors matter for your NAICS codes and your target agencies, whichever match how your market actually buys, then build a habit around those specifically, rather than trying to watch everything everywhere. A quiet portal you never had a reason to use is not a loss.