DFARS is the Department of Defense's supplement to the FAR, layering defense-specific requirements on top of the baseline procurement regulation. It is structured in parallel to the FAR — DFARS Part numbers mirror their FAR counterparts — and applies to all DoD contracts and to civilian-agency contracts using DoD funding. Where the FAR sets the floor, DFARS sets the additional ceiling for contracts that touch national security, controlled technology, or defense-unique acquisition channels. The clauses incorporated by reference into a DoD solicitation determine what compliance applies; the contract's clause matrix is the operative document, not the regulation in the abstract.
Several DFARS clause families carry disproportionate operational weight. DFARS 252.204-7012, 7019, 7020, and 7021 govern Controlled Unclassified Information handling and Cybersecurity Maturity Model Certification. DFARS 252.225-7008 and the Specialty Metals clause restrict country-of-origin sourcing for specific metals. DFARS 252.227 governs technical data and software rights, with stricter assertion procedures than the civilian FAR equivalents. DFARS 252.204-7008 and the supply chain risk clauses restrict sourcing from prohibited foreign vendors. Each of these clauses creates flowdown obligations for subcontractors at every tier.
For small DoD contractors, DFARS fluency is not optional. Compliance failures show up as proposal rejections, modifications imposing new requirements, and post-award audits. The most common entry-cost is the CMMC compliance package, which now applies to most DoD subcontracts handling CUI. Reading the relevant DFARS clauses cited in each solicitation is the minimum due diligence.