Sector 21 — Mining, Quarrying, and Oil and Gas Extraction
Reference listings and standards for industries classified under NAICS Sector 21. Select a national industry below for SBA size bounds and SIC mappings.
Top Industries & SBA Standards under Sector 21
| Code | Industry Title | SBA Size Standard |
|---|---|---|
| 211120 | Crude Petroleum Extraction | 1,250 employees |
| 211130 | Natural Gas Extraction | 1,250 employees |
| 212114 | Surface Coal Mining | 1,250 employees |
| 212115 | Underground Coal Mining | 1,500 employees |
| 212210 | Iron Ore Mining | 1,400 employees |
| 212220 | Gold Ore and Silver Ore Mining | 1,500 employees |
| 212230 | Copper, Nickel, Lead, and Zinc Mining | 1,400 employees |
| 212290 | Other Metal Ore Mining | 1,250 employees |
| 212311 | Dimension Stone Mining and Quarrying | 500 employees |
| 212312 | Crushed and Broken Limestone Mining and Quarrying | 750 employees |
💡 Sector Guidance
Sector Selection Rule: When registering your business profile on SAM.gov or state registers, you must declare a single primary NAICS code representing your largest source of revenue. While you can add multiple secondary codes from Sector 21 (Mining, Quarrying, and Oil and Gas Extraction) to showcase your full capability list, only one primary code dictates your macro size eligibility.
National Industries in this Sector (21)
Frequently Asked Questions
What is NAICS Sector 21? ▾
Sector 21 represents 'Mining, Quarrying, and Oil and Gas Extraction' in the North American Industry Classification System (NAICS) taxonomy. It groups establishments based on their shared production processes and operational inputs.
How many U.S. national industries are listed under NAICS Sector 21? ▾
There are exactly 21 6-digit U.S. national industries listed under NAICS Sector 21 in our registry, compiled from the active 2022 Census NAICS manual.
What is the hierarchical structure under Sector 21? ▾
Economic activities in Sector 21 are organized hierarchically: the first two digits designate Sector 21, which rolls down into 3-digit subsectors, 4-digit industry groups, 5-digit NAICS industries, and 6-digit national industries.
What type of business activities belong to Sector 21? ▾
Sector 21 covers establishments engaged in 'Mining, Quarrying, and Oil and Gas Extraction'. Select any specific six-digit industry code from the directory list to see detailed definitions and examples.
How do I determine the SBA size standard for codes in Sector 21? ▾
Each industry in Sector 21 has its own specific size standard limit set by the SBA. You must check the individual six-digit industry page to see if it is a receipts-based limit or employee-based limit.
Do Sector 21 industries map to legacy SIC codes? ▾
Yes, every six-digit industry in Sector 21 maps to one or more legacy four-digit SIC codes. The concordance crosswalk handles splits to map legacy files to modern formats.
What are the common IRS Principal Business Activity codes for this sector? ▾
The IRS Principal Business Activity (PBA) codes for Sector 21 are derived directly from these NAICS classifications and must be listed on federal tax returns to group business income.
Is a NAICS code in Sector 21 state-specific? ▾
No, all NAICS classifications in Sector 21 are federal standards uniform across all 50 states, ensuring consistent statistics and compliance.
Sources & References
- U.S. Census Bureau: North American Industry Classification System (NAICS) Manual
- U.S. Small Business Administration (SBA): Table of Small Business Size Standards
- Electronic Code of Federal Regulations (eCFR): 13 CFR Part 121 - Small Business Size Regulations
- Acquisition.gov: Federal Acquisition Regulation (FAR) Part 19 - Small Business Programs
- Internal Revenue Service (IRS): Instructions for Schedule C (Form 1040) Principal Business Activity (PBA) Codes
- U.S. General Services Administration (GSA): System for Award Management (SAM.gov) Unique Entity ID Guide
- Defense Logistics Agency: Defense Logistics Agency (DLA) CAGE Search and Registration
- United Nations Statistics Division: International Standard Industrial Classification of All Economic Activities (ISIC)
- U.S. Occupational Safety and Health Administration (OSHA): Standard Industrial Classification (SIC) Manual
- U.S. Securities and Exchange Commission (SEC): SEC EDGAR Filer Standard Industrial Classification Codes