Revenue-Based
Computer Systems Design Services
NAICS 541512 covers companies that plan and design computer systems integrating hardware, software, and communications technologies. This is one of the most heavily competed NAICS codes in federal IT procurement, used for enterprise architecture, cloud migration, systems integration, and digital transformation contracts across every federal agency.
Custom Computer Programming Services
NAICS 541511 encompasses firms that write, modify, test, and support software to meet the needs of particular customers. This code is frequently used for custom application development, software engineering, DevSecOps, and agile development contracts. It is distinct from 541512 (systems design) but often appears alongside it on federal solicitations.
Engineering Services
NAICS 541330 covers firms that apply physical laws and principles of engineering in the design, development, and utilization of machines, materials, instruments, structures, processes, and systems. This includes civil, mechanical, electrical, environmental, and structural engineering services.
Administrative Management and General Management Consulting Services
NAICS 541611 covers firms that provide operating advice and assistance to businesses and other organizations on administrative management issues such as financial planning, human resource policies, organizational planning, and strategic management. This is one of the most broadly used consulting NAICS codes in federal procurement.
Other Computer Related Services
NAICS 541519 is a catch-all code for computer-related services not classified elsewhere, including data recovery, computer disaster recovery, IT asset management, and software installation. Federal agencies frequently use this code for cybersecurity services, help desk operations, and IT support services that do not fit neatly into other IT NAICS codes.
Commercial and Institutional Building Construction
NAICS 236220 covers general contractors and operative builders primarily engaged in the construction of commercial and institutional buildings, including office buildings, hospitals, schools, and government facilities. This is the primary NAICS code for federal building construction projects.
Facilities Support Services
NAICS 561210 covers establishments that provide operating staff to perform a combination of support services within a client's facilities, including janitorial, maintenance, trash disposal, guard and security, mail routing, reception, and laundry services. This code is commonly used for base operations support (BOS) contracts.
Security Guards and Patrol Services
NAICS 561612 covers establishments primarily engaged in providing guard and patrol services such as bodyguard, guard dog, and parking security services. Federal agencies use this code extensively for physical security at government buildings, military installations, and critical infrastructure sites.
Plumbing, Heating, and Air-Conditioning Contractors
NAICS 238220 covers specialty trade contractors primarily engaged in installing and servicing plumbing, heating, and air-conditioning equipment. This includes HVAC installation and repair, plumbing system installation, and mechanical systems work in both new construction and building renovation projects.
Wired Telecommunications Carriers
NAICS 517110 covers establishments that operate, maintain, or provide access to transmission facilities and infrastructure for telecommunications. This includes local and long-distance telephone carriers, cable and internet service providers, and firms that provide voice and data transmission over wired networks.
Software Publishers
NAICS 511210 covers establishments that carry out operations necessary for producing and distributing computer software, including designing, providing documentation, assisting in installation, and providing support services. This code distinguishes software product companies from custom software developers (541511).
Temporary Help Services
NAICS 561320 covers establishments that supply workers to clients on a temporary basis. These workers are employees of the temporary help service, not the client. Federal agencies use temporary staffing services for surge capacity, specialized skills, and filling gaps during hiring freezes.
Computer and Computer Peripheral Equipment and Software Merchant Wholesalers
NAICS 423430 covers merchant wholesalers that distribute computers, computer peripherals, and pre-packaged software. This code is used by IT resellers and value-added resellers (VARs) that supply hardware and software to federal agencies.
Drywall and Insulation Contractors
NAICS 812320 covers establishments primarily engaged in providing dry cleaning and laundry services. This includes coin-operated laundromats, commercial laundry plants, and dry cleaning plants that serve both retail and institutional customers.
Full-Service Restaurants
NAICS 722511 covers establishments that provide food services to patrons who order and are served while seated and pay after eating. This code is used for dining facility operations at federal installations, conference centers, and government-operated food service venues.
Offices of Physicians (except Mental Health Specialists)
NAICS 621111 covers establishments of health practitioners having the degree of M.D. or D.O. that are primarily engaged in the independent practice of general or specialized medicine. Federal agencies contract for physician services to supplement government medical staff.
Offices of Real Estate Agents and Brokers
NAICS 531210 covers establishments that are primarily engaged in acting as agents or brokers in selling real estate for others, buying real estate for others, and renting or leasing real estate for others.
Employee-Based
Research and Development in the Physical, Engineering, and Life Sciences (except Nanotechnology and Biotechnology)
NAICS 541715 covers establishments that conduct research and experimental development in physical, engineering, and life sciences. This includes defense research laboratories, applied physics research, materials science, and environmental science research conducted under government contracts and grants.
Aircraft Manufacturing
NAICS 336411 covers establishments that manufacture or assemble complete aircraft, including fixed-wing aircraft, helicopters, gliders, and other aerospace vehicles. This is one of the most strategically important manufacturing NAICS codes for national defense, covering military fighter jets, transport aircraft, unmanned aerial vehicles, and commercial aviation platforms.
Search, Detection, Navigation, Guidance, Aeronautical, and Nautical System and Instrument Manufacturing
NAICS 334511 covers establishments that manufacture search, detection, navigation, guidance, aeronautical, and nautical systems and instruments. This includes radar systems, sonar equipment, GPS receivers, flight instruments, and electronic warfare systems that are critical to military operations and national defense.
About SBA Size Standards
The U.S. Small Business Administration (SBA) establishes size standards for each industry, identified by NAICS code, to determine whether a business qualifies as "small" for federal contracting purposes. Revenue-based standards use the firm's average annual receipts over the past five years, while employee-based standards use the average number of employees over 24 pay periods.
Size standards are critical for federal contractors because they determine eligibility for small business set-aside contracts, which represent approximately 23% of all federal contracting dollars. Firms that exceed their applicable size standard lose eligibility for programs including 8(a) Business Development, HUBZone, Service-Disabled Veteran-Owned Small Business (SDVOSB), and Women-Owned Small Business (WOSB) set-asides.