Sector 54: Professional, Scientific, and Technical Services NAICS 541100 - Legal Services NAICS 541200 - Accounting, Tax Preparation, Bookkeeping, and Payroll Services NAICS 541300 - Architectural, Engineering, and Related Services NAICS 541400 - Specialized Design Services NAICS 541500 - Computer Systems Design and Related Services NAICS 541600 - Management, Scientific, and Technical Consulting Services NAICS 541700 - Scientific Research and Development Services NAICS 541800 - Advertising, Public Relations, and Related Services NAICS 541900 - Other Professional, Scientific, and Technical Services