Understanding FAR and DFARS is essential for any business working with the U.S. government or Department of Defense (DoD). In the first stages of government contracting, confusion around what FAR and DFARS are and how they differ can create compliance risks, contract delays, and costly mistakes.
This guide breaks down FAR vs DFARS, explains regulations, and clarifies the difference between FAR and DFARS clauses so contractors know exactly what applies to their contracts and why it matters.
What Is FAR and DFARS?
FAR stands for the Federal Acquisition Regulation, while DFARS refers to the Defense Federal Acquisition Regulation Supplement. Together, FAR and DFARS establish the rules federal agencies and contractors must follow when acquiring goods and services under DOD contracts.
Federal Acquisition Regulation (FAR)
The Federal Acquisition Regulation is the primary rulebook governing all federal government procurement. It applies to all executive agencies, not just defense-related contracts.
FAR establishes:
- Standard contract clauses
- Procurement procedures
- Cost principles
- Ethics and compliance requirements
- Contractor responsibilities
Every government contract starts with FAR.
Defense Federal Acquisition Regulation Supplement (DFARS)
DFARS supplements FAR specifically for the Department of Defense. It adds DoD-specific rules, cybersecurity requirements, cost accounting expectations, and national security protections, amongst other agency-specific interests.
If a contract involves the DoD, defense agencies, or defense contractors, DFARS applies in addition to FAR—not instead of it.
FAR vs DFARS: The Key Difference Explained
The simplest way to understand FAR vs DFARS is this:
- FAR = Base regulations for all federal contracts
- DFARS = Additional rules layered on top for defense contracts
Core Differences Between FAR and DFARS
| Area | FAR | DFARS |
| Scope | All federal agencies | Department of Defense only |
| Purpose | Standardize procurement | Address defense, security, and military needs |
| Applicability | Universal | Conditional (DoD contracts only) |
| Cybersecurity | Basic requirements | Advanced requirements (e.g., NIST, CMMC) |
| Cost Controls | Standard | Enhanced oversight and reporting |
Understanding the difference between FAR and DFARS clauses is critical because DFARS clauses often impose stricter compliance obligations.
What Is the Difference Between FAR and DFAR Clauses?
FAR clauses apply broadly across government contracts, while DFARS clauses address defense-specific risks such as data security, supply chain integrity, and classified information.
Examples of FAR Clauses
- Allowable cost principles
- Contract termination procedures
- Payment and invoicing standards
- Ethics and conflicts of interest
Examples of DFAR Clauses
- Supplemental allowable cost principles
- Business system requirements
- Cybersecurity controls (NIST SP 800-171)
- Controlled Unclassified Information (CUI) handling
- Domestic sourcing requirements
- Reporting foreign influence or ownership
Failing to comply with DFARS clauses even unintentionally can result in:
- Contract termination
- Withheld payments
- DCAA audit findings
- Disqualification from future awards
FAR and DFAR Regulations: Why Compliance Matters
Compliance with FAR and DFAR regulations is not optional. Federal agencies and the DoD expect contractors to understand, implement, and document compliance from day one.
Risks of Non-Compliance
- Failed audits (DCAA, DCMA)
- Contract disputes
- Financial penalties
- Reputational damage
- Loss of government eligibility
Benefits of Strong FAR & DFARS Compliance
- Faster contract approvals
- Lower audit risk
- Improved pricing credibility
- Competitive advantage in bids
Contractors who proactively manage FAR and DFARS requirements are more attractive to contracting officers and primes.
Who Needs to Follow FAR and DFARS?
Not every contractor needs DFARS compliance, but every federal contractor must follow FAR.
FAR Applies To:
- All federal contractors
- Prime contractors and subcontractors
- Service providers and product vendors
DFARS Applies To:
- DoD prime contractors
- Defense subcontractors
- IT, cybersecurity, engineering, and manufacturing firms
- Any contract flowing down DFARS clauses
If your contract references DFARS, compliance is mandatory—even as a subcontractor.
FAR vs DFARS: How to Tell Which Applies to Your Contract
To determine whether FAR, DFARS, or both apply:
- Review the contract clauses section
- Look for references to:
- FAR Part numbers
- DFARS clause numbers (e.g., DFARS 252.xxx)
- Identify the contracting agency
- Check for flow-down requirements from primes
When in doubt, seeking professional guidance misinterpreting FAR vs DFARS applicability is a common and costly error.
Common FAR and DFARS Mistakes Contractors Make
Even experienced government contractors make avoidable mistakes when navigating FAR and DFARS. These errors often stem from misinterpreting regulations, overlooking clause flow-downs, or underestimating compliance requirements. Understanding the most common FAR and DFARS mistakes can help contractors reduce audit risk, avoid contract delays, and protect long-term eligibility for federal and defense work.
- Assuming DFARS Doesn’t Apply to Subcontractors
Incorrect. Many DFARS clauses flow down automatically.
- Ignoring Cybersecurity Requirements
DFARS cybersecurity clauses are among the most enforced requirements.
- Using Commercial Accounting Systems
Defense contracts often require job-costing and compliance-ready accounting systems.
- Treating Compliance as “Later”
FAR and DFARS compliance must be built before bidding, not after award.
Best Practices for Managing FAR and DFARS Compliance
Successfully managing FAR and DFARS compliance requires a proactive, systemized approach, not reactive fixes after a contract is awarded. Contractors that implement best practices early are better positioned to pass audits, maintain contract performance, and scale confidently in federal and defense markets. The following best practices outline how to reduce risk, improve oversight, and stay compliant as requirements evolve.
Top priorities:
- Contract review process before bidding
- Compliance-ready accounting systems
- Cybersecurity controls aligned with DFARS
- Documented policies and procedures
- Internal compliance audits
For defense contractors, aligning FAR and DFARS compliance with DCAA expectations is especially critical.
FAR and DFARS Are Strategic, Not Just Regulatory
The difference between FAR and DFARS, and how FAR and DFAR regulations impact your contracts is a strategic advantage, not just a compliance requirement.
Contractors who master FAR and DFARS early:
- Win more bids
- Reduce audit risk
- Scale confidently in federal and defense markets
If government or defense contracts are part of your growth plan, FAR and DFARS compliance must be part of your foundation.
Get Expert FAR and DFARS Compliance Support
Navigating FAR and DFARS compliance doesn’t have to be overwhelming. RKI helps government contractors build compliant systems, reduce audit risk, and stay contract-ready at every stage. If you want confidence that your accounting, compliance, and reporting align with FAR and DFARS requirements, schedule a consultation with RKI today and take the next step toward stronger, audit-ready operations.