NAICS became the federal statistical classification standard in 1997, replacing SIC for that specific purpose. However, SIC did not disappear and was not eliminated from all government or business use. SIC continues to be used in current government filing, permitting, regulatory, tax, search, financial, business-data, and commercial classification systems.
If the question is which classification system federal statistical agencies use as their standard, the answer is NAICS. If the question is whether SIC stopped being used, became universally obsolete, or was removed from government and business systems, the answer is no. The correct code depends on the agency, form, dataset, filing system, or business purpose involved.
Updated: September 2026 · Reviewed by the SICCODE.com Industry Classification Review Team
The confusion comes from treating several different questions as if they were the same. “Did NAICS replace SIC?” has a different answer depending on the system and purpose being discussed.
The North American Industry Classification System was adopted in 1997 as the standard used by U.S. federal statistical agencies to classify business establishments for the collection, analysis, and publication of economic statistics. For that purpose, NAICS replaced the Standard Industrial Classification system.
That change was significant, but its scope matters. It established NAICS as the federal statistical standard. It did not create a rule requiring every government filing system, regulator, permit program, tax authority, financial system, business database, or commercial data provider to stop using SIC.
Primary background: U.S. Census Bureau NAICS and Bureau of Labor Statistics introduction to NAICS.
The statement comes from a real policy change, but the qualifier is often lost. NAICS replaced SIC for federal statistical classification. When that narrower statement is shortened to “NAICS replaced SIC,” it can sound as if SIC was abolished everywhere.
Current government systems show why that broader interpretation is not accurate. SIC still appears in active filing, regulatory, permitting, tax, search, and reference workflows. Outside government, SIC also remains widely used in business data, financial applications, market segmentation, analytics, and historical datasets.
These examples show current government use or direct support of SIC. They are not merely historical references.
| Agency / system | How SIC is used | Type of use | Primary source |
|---|---|---|---|
| SEC EDGAR | SIC codes appear in EDGAR filings and search. The SEC also states that the Division of Corporation Finance uses SIC as a basis for assigning filing-review responsibility. | Active operational use | SEC SIC Code List Verified September 2026 |
| DOJ Antitrust Division | The Division maintains an official list of NAICS and SIC industry codes used by the Division, and its current case-filings interface links to that list. | Current agency classification support | DOJ Industry Codes Verified September 2026 |
| EPA NPDES permits | EPA's current NPDES application process uses Form 1, which contains separate SIC Code(s) and NAICS Code(s) fields. | Current federal application field | EPA NPDES Applications Verified September 2026 |
| OSHA | OSHA maintains a searchable version of the 1987 SIC Manual and SIC-based search support for inspection information. | Current reference and search support | OSHA SIC Search Help Verified September 2026 |
| Texas Comptroller | Current franchise-tax guidance includes separate SIC and NAICS industry-classification fields and instructs filers to enter the appropriate code for each. | Current state tax-reporting field | Texas Franchise Tax Help Verified September 2026 |
For a broader source-supported review of current federal and state SIC use, see What Government Agencies Still Use SIC Codes?
Federal statistical agencies moved to NAICS as their standard classification framework. Current official U.S. economic statistics are generally organized around NAICS rather than SIC.
SIC was not erased from all government systems, prohibited from business use, or converted automatically into NAICS. Existing and current systems can continue to use SIC when it fits their own requirements.
Yes. SIC remains widely used in commercial business data, financial and credit applications, customer and prospect classification, market segmentation, analytics, business intelligence, internal data systems, and historical datasets.
Commercial business-data systems may also add more detailed Extended SIC classifications below the official 4-digit SIC industry. These commercial extensions should remain distinguishable from the official U.S. SIC structure.
No. NAICS was not created by simply adding digits to SIC, and the two systems do not define every industry in the same way. A SIC industry may correspond to more than one NAICS industry, and a NAICS industry may correspond to more than one SIC industry.
A crosswalk is therefore a mapping tool, not proof that two codes represent exactly the same industry boundary. When classification accuracy matters, verify the underlying activity and the destination code definition.
See SIC to NAICS Conversion, NAICS to SIC Conversion, and NAICS vs SIC Codes.
Use the classification required by the specific form, agency, database, reporting system, or business workflow. There is no universal rule that NAICS should replace SIC in every application simply because NAICS is the federal statistical standard.
Some systems use NAICS, some use SIC, and some maintain both. If both codes are relevant, keep them as separate classification fields and verify any mapping between them rather than assuming an exact one-to-one conversion.
The distinction on this page is based on official government sources that document both the adoption of NAICS and continuing SIC use in specific current systems.
It depends on the context. NAICS replaced SIC as the federal statistical classification standard in 1997. SIC was not eliminated from all other government, business, financial, or commercial systems and remains in active use today.
Yes. Current government examples include SEC EDGAR, DOJ Antitrust industry-code support, EPA NPDES applications, OSHA SIC search tools, and Texas franchise-tax reporting. SIC also remains widely used in commercial business data.
No. The principal official U.S. SIC reference remains the 1987 SIC Manual, while SIC continues to be used in current government and commercial systems. Its federal statistical status changed when NAICS was adopted, but that did not end SIC use.
Census is describing the federal statistical classification system. NAICS became the standard used by federal statistical agencies in 1997. That statement does not mean SIC was eliminated from every other government or private-sector application.
Yes. A business or establishment may be represented in datasets that contain both classifications. Because the systems have different structures and boundaries, the codes should be treated as separate classifications rather than assumed to be exact equivalents.
Use the code requested by the specific form or agency. Some current government systems request NAICS, some use SIC, and some request both.