FAR vs DFARS Understanding Federal Acquisition Regulations

What Is the FAR (Federal Acquisition Regulation)?

The Federal Acquisition Regulation (FAR), codified in Title 48, Chapter 1 of the Code of Federal Regulations, is the primary set of rules governing the federal government's acquisition of supplies and services. The FAR applies to all executive branch agencies and establishes uniform policies and procedures for the entire federal acquisition process, from planning through contract closeout.

The FAR is jointly issued by the Department of Defense (DoD), the General Services Administration (GSA), and the National Aeronautics and Space Administration (NASA) through the FAR Council. It is organized into 53 parts covering topics including competition requirements (Part 6), contract types (Part 16), small business programs (Part 19), cost principles (Part 31), and contract clauses (Parts 52–53).

Every federal contractor must comply with the FAR. The regulation covers the entire acquisition lifecycle: how the government determines needs, conducts market research, selects acquisition strategies, evaluates proposals, awards contracts, administers performance, and closes out completed work. Key contractor-facing provisions include cost principles (what costs are allowable), truth in negotiations requirements, and mandatory contract clauses.

What Is DFARS (Defense Federal Acquisition Regulation Supplement)?

The Defense Federal Acquisition Regulation Supplement (DFARS), codified in Title 48, Chapter 2 of the CFR, supplements the FAR with defense-specific policies and procedures. DFARS is issued by the Department of Defense and applies to all DoD acquisitions, including those by the Army, Navy, Air Force, Space Force, defense agencies (DLA, DISA, MDA), and other DoD components.

DFARS does not replace the FAR — it adds to it. When a DFARS provision conflicts with a FAR provision, DFARS takes precedence for DoD contracts. DFARS parts mirror the FAR numbering system (DFARS Part 225 supplements FAR Part 25 on foreign acquisition, for example), making cross-referencing straightforward. DFARS clauses use the 252.xxx numbering convention versus FAR's 52.xxx.

Key DFARS areas include cybersecurity requirements (DFARS 252.204-7012, the foundation for CMMC), domestic sourcing restrictions (Berry Amendment, specialty metals), data rights provisions unique to DoD, foreign military sales procedures, and DoD-specific small business programs. DFARS also implements congressional mandates specific to defense procurement, which change frequently through the annual National Defense Authorization Act (NDAA).

Agency Supplements Beyond DFARS

DFARS is the most well-known FAR supplement, but many other agencies issue their own supplements that add agency-specific requirements to the FAR. Understanding which supplement applies to your contract is essential for compliance.

How to Navigate FAR and DFARS

The FAR and DFARS follow a parallel numbering structure that makes navigation logical once you understand the system. FAR parts are numbered 1 through 53, with each part covering a specific topic. DFARS mirrors this structure with 200-series numbers (FAR Part 15 on contracting by negotiation corresponds to DFARS Part 215).

When reviewing a contract clause, check both the FAR clause and any corresponding DFARS clause. For example, if your contract includes FAR 52.204-21 (Basic Safeguarding of Covered Contractor Information Systems), a DoD contract will likely also include DFARS 252.204-7012, which imposes significantly more stringent cybersecurity requirements.

The official sources for the current FAR and DFARS are acquisition.gov (FAR) and the Defense Acquisition Regulations System website (DFARS). Both are available online for free. Third-party services like Acquisition Central, Westlaw, and various govcon tools provide searchable versions with cross-references and annotations.

For contractors new to the regulatory framework, start by reading the FAR parts most relevant to your contract type: Part 12 (commercial items), Part 15 (negotiated procurements), Part 16 (contract types), Part 19 (small business), and Part 31 (cost principles). Then review the corresponding DFARS parts if you are pursuing DoD work.

When DFARS Applies vs Just FAR

The simplest rule: if you are contracting with any DoD component (Army, Navy, Air Force, Space Force, Marines, or any defense agency), both FAR and DFARS apply. If you are contracting with a civilian agency (VA, HHS, DHS, DOE, GSA, etc.), the FAR applies along with that agency's specific supplement, but not DFARS.

There are edge cases. Governmentwide contract vehicles like GSA Schedules and OASIS+ are governed by the FAR and GSAM, but individual task orders placed by DoD agencies against those vehicles may incorporate DFARS clauses. Similarly, interagency acquisitions where a civilian agency procures on behalf of DoD may trigger DFARS requirements. Always check the specific clauses in your contract or task order.

The practical impact is significant. DoD contractors face additional compliance requirements including CMMC cybersecurity certification, Berry Amendment domestic sourcing, specialty metals restrictions, DoD-specific data rights provisions, and enhanced reporting. These DFARS requirements add cost and complexity. Civilian agency contractors generally face fewer supplemental requirements, though agencies like DHS and DOE have their own demanding supplement provisions.