What is the difference between a NAICS code and a Product Service Code (PSC)?

A NAICS code classifies your business by its economic activity, while a Product Service Code (PSC) classifies the specific product or service being bought by the government. You need both for your SAM.gov registration. NAICS codes determine your business's size standard and eligibility for certain set-aside contracts, such as a Woman-Owned Small Business (WOSB) award. For example, your 561720 NAICS code for janitorial services allows the government to identify you as a small business based on your annual receipts. PSCs are used by agencies to categorize what they are buying, which helps with market research and tracking spending. In SAM.gov contract award data, a PSC is a 4-character value and a NAICS code is a 6-character value. Agencies use PSCs like S201 for Custodial Services to define the scope of work more granularly within a broader NAICS category. When you search for opportunities, you can use both to narrow down relevant solicitations. The government often uses the NAICS code to identify potential small business concerns for a set-aside and the PSC to describe the specific work.