NAICS 238120

Overview

NAICS 238120 — Structural Steel and Precast Concrete Contractors — covers specialty trade establishments that primarily erect structural steel and install precast concrete components at the construction site. Typical activities include setting columns, beams, joists, and metal decking; installing precast panels, beams, slabs, and girders; and placing reinforcing steel (rebar) as part of a structural system. Work spans new construction, additions, alterations, maintenance, and repair for buildings and other structures, including bridges and industrial facilities. The emphasis is on on-site erection/installation rather than manufacturing or general contracting. Establishments that primarily fabricate structural steel or manufacture precast products off site are classified in manufacturing sectors, not in 238120. Classification is based on the establishment’s primary activity, and separate establishments of the same enterprise may be classified differently if their principal activities differ. ¹

What this NAICS covers

238120 — Structural Steel and Precast Concrete Contractors — comprises specialty trade contractors that primarily erect structural steel and install precast concrete components for buildings and other structures. Activities encompass new construction, additions, alterations, maintenance, and repair of structural frames and components. The focus is on on-site erection and installation rather than manufacturing or general contracting. ¹

Included work (illustrative):

• Erecting structural steel frameworks (e.g., columns, beams, girders, trusses) for buildings and other structures. ¹
• Installing precast concrete structural elements (e.g., panels, beams, slabs, girders), including setting, aligning, and making structural connections. ¹
• Placing and tying concrete reinforcing steel (rebar) and welded wire fabric for reinforced concrete members. ¹
• Erecting steel joists and installing metal decking as part of a structural system. ¹
• Performing additions, alterations, maintenance, and repair to structural steel and precast concrete components. ¹

Boundaries and exclusions (classified elsewhere):

• Pouring, finishing, and site-forming cast-in-place concrete (e.g., foundations, slabs): 238110 Poured Concrete Foundation and Structure Contractors. ⁶
• Manufacturing (shop-fabricating) structural steel components and assemblies: 332312 Fabricated Structural Metal Manufacturing. ⁷
• Manufacturing precast concrete products and elements: 327390 Other Concrete Product Manufacturing. ⁸

Key point of distinction: establishments in 238120 perform on-site erection/installation of structural steel and precast concrete. They do not primarily manufacture those components and are not classified here when their principal activity is producing (fabricating) the structural steel or precast concrete elements off site. ¹

Related NAICS and PSC codes

• NAICS codes:

  • 238110 — Poured Concrete Foundation and Structure Contractors; cast-in-place concrete (e.g., footings, foundations, slabs) rather than precast installation or steel erection. ⁶
  • 238130 — Framing Contractors; building framing (e.g., wood/metal studs, joists, rafters) rather than primary structural steel erection. ⁹
  • 238190 — Other Foundation, Structure, and Building Exterior Contractors; miscellaneous structural/exterior specialty trades not elsewhere classified. ¹⁰
  • 332312 — Fabricated Structural Metal Manufacturing; shop fabrication of structural steel components (manufacturing) rather than on-site erection. ⁷
  • 327390 — Other Concrete Product Manufacturing; production of precast concrete elements instead of on-site installation. ⁸
  • 237310 — Highway, Street, and Bridge Construction; prime contracting for bridges and roadways, with steel/precast erection often subcontracted. ¹¹

• PSC codes:

  • Y1 — Construction of structures and facilities; used for new construction awards that can include structural steel or precast erection. ⁴
  • Z2 — Repair or alteration of structures or facilities; used for renovations/retrofits involving modifications to structural frames. ⁴
  • Z1 — Maintenance of structures and facilities; used for recurring maintenance of structural components. ⁴
  • C1 — Architect and Engineering—Construction; A/E services supporting design and construction-phase activities related to structural steel or precast scopes. ⁴

Frequently asked questions

• What activities are included in NAICS 238120?
  Establishments in 238120 perform on-site erection of structural steel (columns, beams, joists) and installation of precast concrete elements, including placing reinforcing steel and making structural connections, for new work, additions, alterations, maintenance, and repair. Manufacturing components off site is not included. ¹

• How is 238120 different from 238110?
  238110 covers cast-in-place concrete (forming, placing, and finishing foundations, slabs, and similar work). 238120 focuses on erecting structural steel and installing precast concrete components at the site rather than forming and pouring in place. ⁶

• Does rebar installation fall under 238120?
  Yes. Placing and tying reinforcing steel (rebar) or welded wire fabric for reinforced concrete members when performed as part of a structural system is explicitly within 238120. ¹

• Which PSCs commonly pair with NAICS 238120 in federal awards?
  Common PSC families include Y1 (new construction), Z2 (repair/alteration), Z1 (maintenance), and C1 for A/E support. PSCs describe the purchased service; NAICS identifies the contractor’s industry. ⁴

• What is the SBA small business size standard for 238120?
  SBA size standards are established by NAICS code and periodically updated. For the current receipts-based size standard applicable to 238120, consult Appendix A to 13 CFR 121 (SBA Table of Size Standards) and confirm the latest effective figure. ³

Useful resources

• Official NAICS page for 238120 — Structural Steel and Precast Concrete Contractors: definition, examples, and classification guidance direct from the Census Bureau’s NAICS search tool. ¹
• 2022 NAICS Manual (PDF): sector 23 (Construction) narrative, scope notes, and cross‑references that clarify where 238120 fits within Specialty Trade Contractors. ⁵
• SBA size standards (Appendix A to 13 CFR 121): authoritative table used to determine the current receipts-based small business size standard applicable to 238120. ³
• NAICS selection and appeals rules (13 CFR 121.402): SBA regulation on assigning a single NAICS code to each solicitation/contract and the process for challenges. ²
• Boundary reference — 238110 Poured Concrete Foundation and Structure Contractors: covers cast‑in‑place forming/placing that is excluded from 238120. ⁶
• Boundary reference — 332312 Fabricated Structural Metal Manufacturing: shop fabrication/manufacturing of structural steel (not on‑site erection). ⁷
• Boundary reference — 327390 Other Concrete Product Manufacturing: production of precast concrete elements, distinct from field installation in 238120. ⁸
• PSC alignment aid — PSC Manual and search tool: helps select PSCs commonly paired with 238120 scopes (e.g., Y1, Z2, Z1, C1). ⁴

References

1. U.S. Census Bureau. NAICS 2022 Search — Structural Steel and Precast Concrete Contractors (detail page). https://www.census.gov/naics/?input=238120&year=2022&details=238120
2. U.S. Small Business Administration. 13 CFR § 121.402 — What size standards are applicable to Federal Government Contracting programs? https://www.ecfr.gov/current/title-13/part-121/section-121.402
3. U.S. Small Business Administration. Appendix A to 13 CFR Part 121 — Small Business Size Standards by NAICS Industry. https://www.ecfr.gov/current/title-13/part-121/appendix-Appendix%20A%20to%20Part%20121
4. Product and Service Code (PSC) Manual and Search Tool. https://psctool.us/psc-manual
5. U.S. Census Bureau. 2022 NAICS Manual (PDF). https://www.census.gov/naics/2022NAICS/2022_NAICS_Manual.pdf
6. U.S. Census Bureau. NAICS 2022 Search — Poured Concrete Foundation and Structure Contractors (detail page). https://www.census.gov/naics/?input=238110&year=2022&details=238110
7. U.S. Census Bureau. NAICS 2022 Search — Fabricated Structural Metal Manufacturing (detail page). https://www.census.gov/naics/?input=332312&year=2022&details=332312
8. U.S. Census Bureau. NAICS 2022 Search — Other Concrete Product Manufacturing (detail page). https://www.census.gov/naics/?input=327390&year=2022&details=327390
9. U.S. Census Bureau. NAICS 2022 Search — Framing Contractors (detail page). https://www.census.gov/naics/?input=238130&year=2022&details=238130
10. U.S. Census Bureau. NAICS 2022 Search — Other Foundation, Structure, and Building Exterior Contractors (detail page). https://www.census.gov/naics/?input=238190&year=2022&details=238190
11. U.S. Census Bureau. NAICS 2022 Search — Highway, Street, and Bridge Construction (detail page). https://www.census.gov/naics/?input=237310&year=2022&details=237310