A Large Category is the top-level classification used within the GSA Multiple Award Schedule (MAS) program to organize products and services following the 2019–2020 MAS Consolidation. GSA introduced the Large Category structure to replace the 24 separate legacy Schedules with a unified, streamlined framework, simplifying acquisition for both government buyers and contractors.
There are 12 Large Categories in the MAS structure, each representing a broad area of federal procurement, such as Information Technology, Professional Services, or Facilities. Each Large Category contains multiple Subcategories and Special Item Numbers (SINs) that define more specific offerings.
Purpose of Large Categories
The Large Category model serves several key purposes:
- Simplifies contract structure by consolidating and standardizing classification across offerings
- Improves searchability for buyers in systems like GSA eLibrary and GSA Advantage!
- Supports Category Management initiatives across the federal government
- Makes it easier for contractors to manage contracts that span multiple service areas
- Aligns GSA’s procurement taxonomy with government-wide acquisition goals
This tiered classification system is now the foundation of how the MAS program is organized and administered.
Structure of the MAS Classification System
The MAS contract is organized into three levels:
- Large Category – The broadest grouping of related goods or services
- Subcategory – A refined grouping within each Large Category, offering more detailed segmentation
- Special Item Number (SIN) – The most specific level, identifying exactly what is being offered and purchased
For example:
- Large Category: Information Technology
- Subcategory: IT Professional Services
- SIN: 54151S – IT Professional Services
Each SIN maps to NAICS codes and includes a defined scope of work, which contractors must match when offering products or services.
List of Current Large Categories
As of the most recent MAS structure, the 12 Large Categories are:
- Facilities
- Furniture & Furnishings
- Human Capital
- Industrial Products & Services
- Information Technology
- Miscellaneous
- Office Management
- Professional Services
- Scientific Management & Solutions
- Security & Protection
- Transportation & Logistics Services
- Travel
Each of these categories contains its own hierarchy of subcategories and SINs, ensuring that all commercial offerings can be logically grouped.
Contractor Considerations
When submitting an MAS offer or modification, contractors must:
- Select the correct Large Category and SINs that align with their offerings
- Ensure technical proposals and past performance match the SIN scope
- Understand that each Large Category may have different submission requirements, evaluation criteria, and templates
Contractors may hold SINs across multiple Large Categories under the same MAS contract, avoiding the need for multiple contracts.
Buyer Use and Impact
Federal acquisition professionals use Large Categories to:
- Filter vendors and offerings in eBuy, eLibrary, and GSA Advantage!
- Compare pricing and capabilities within a category
- Align purchases with Category Management strategies and Best-in-Class contract goals
- Streamline requisitions and market research by narrowing focus to specific Large Categories
The classification system ensures greater consistency and efficiency across agencies.
Conclusion
The Large Category structure is a foundational element of the modern GSA MAS program. It provides a logical, intuitive, and standardized way to organize federal procurement offerings and helps both contractors and buyers navigate the Schedule more effectively. Understanding your Large Category and how it relates to subcategories and SINs is essential for successful contract management, compliance, and marketing within the GSA ecosystem.
