Understanding the Six-Digit NAICS Coding Structure

The NAICS coding system uses a hierarchical structure where each digit narrows down the industry categorization. Every business establishment is assigned a specific classification based on its production process rather than its end product [1].

  • Digits 1-2 (Sector): Represents the broad economic sector (e.g., Sector 54 represents Professional, Scientific, and Technical Services).
  • Digit 3 (Subsector): Groups industries with similar economic activities (e.g., Subsector 541).
  • Digit 4 (Industry Group): Aggregates related operations (e.g., Industry Group 5415).
  • Digit 5 (Industry): Represents the standard industry classification (e.g., Industry 54151).
  • Digit 6 (National Industry): Represents the most specific U.S. national classification, such as NAICS 541511 for Custom Computer Programming Services.

Worked Example: Hierarchy of NAICS 541511

To see how a specific entity is classified, let us analyze NAICS code 541511 (Custom Computer Programming Services):

TierCodeName
Sector54Professional, Scientific, and Technical Services
Subsector541Professional, Scientific, and Technical Services
Industry Group5415Computer Systems Design and Related Services
Industry54151Computer Systems Design and Related Services
National Industry541511Custom Computer Programming Services

Federal agencies utilize these codes to analyze productivity, compile economic censuses, and determine eligibility for small business contracting assistance [2].