It's simple: If you want to do government contracting at the federal level, then your company needs to be registered in the System for Award Management, or SAM.
SAM is the government's online repository for information about vendors that supply goods and services to federal agencies. It was launched in July, 2012, to eventually consolidate nine legacy vendor/contractor registries and systems into one system; included in phase one of the consolidation were Central Contractor Registration (CCR), Online Representations and Certifications Application (ORCA) and the Excluded Parties List System (EPLS).
As was the case with CCR, SAM is designed to streamline the acquisition process for both the agencies and the suppliers: Instead of having to submit company information on paper to each agency for each bid, a prospective vendor submits that information only once online and then makes updates as necessary; agencies are then able to access the info over the web at any time.
To register with SAM, go to https://www.sam.gov and click on "Create an Account."
Note that in order to complete your registration, you will need your DUNS number, provided by Dunn & Bradstreet; your tax identification number; information about your business, such as the number of employees and annual receipts; and Electronic Funds Transfer (EFT) information for invoice payments. If you have questions about your DUNS number or need a DUNS number, call 1-866-705-5711 or visit the D&B website.