FAR 30.101—Cost Accounting Standards.
Plain-English Summary
FAR 30.101 is the gateway provision for the Cost Accounting Standards (CAS) framework. It explains that 41 U.S.C. chapter 15 requires certain contractors and subcontractors to comply with CAS and to disclose their cost accounting practices in writing and then follow those practices consistently. It also clarifies how contract references to FAR part 30 should be read: those references are treated as including the CAS, as well as other Cost Accounting Standards Board (CASB) regulations issued under 48 CFR chapter 99. In practical terms, this section tells contractors and contracting officers that CAS obligations are not limited to the text of FAR part 30 itself; the incorporated CASB rules are part of the governing framework. The section matters because it establishes the legal basis for cost accounting compliance, disclosure, and consistency requirements that can affect pricing, cost allowability, contract administration, and audit outcomes on covered contracts.
Key Rules
CAS applies to covered contractors
The statute requires certain contractors and subcontractors to comply with Cost Accounting Standards. This means CAS is not universal, but when a contract or subcontract is subject to CAS, the contractor must follow the applicable standards.
Written disclosure is required
Covered contractors must disclose their cost accounting practices in writing. The disclosure requirement creates a formal record of how costs are accumulated, measured, and allocated for government contracting purposes.
Consistent practice is mandatory
Once disclosed, cost accounting practices must be followed consistently. A contractor cannot change practices arbitrarily or apply them differently from one contract or accounting period to another when CAS applies.
Part 30 incorporates CASB rules
Any contract reference to FAR part 30 for applying CASB policies, procedures, standards, and regulations is deemed to include the CAS and other CASB regulations. This prevents a narrow reading that would exclude the broader CASB framework.
Chapter 99 is part of the framework
The CASB regulations found in 48 CFR chapter 99 are incorporated into FAR part 30 by this section. Users must therefore consult chapter 99, not just FAR part 30, to understand the full set of requirements.
Responsibilities
Contractors
Determine whether they are subject to CAS, disclose their cost accounting practices in writing when required, and apply those practices consistently across covered work. They must also follow the incorporated CASB regulations in 48 CFR chapter 99.
Subcontractors
Comply with CAS when the subcontract is covered, and provide written disclosure and consistent application of cost accounting practices as required by the applicable standards and contract flowdown requirements.
Contracting Officers
Recognize when a procurement is subject to CAS, ensure the contract properly reflects the applicable CAS framework, and understand that references to FAR part 30 include the incorporated CASB regulations.
Agencies
Administer procurements and contracts in a manner consistent with the CAS statute, FAR part 30, and the incorporated CASB regulations, including oversight of covered contractor compliance.
Cost Accounting Standards Board (CASB)
Issue the policies, procedures, standards, and regulations that implement the CAS statute, including the regulations codified in 48 CFR chapter 99 and incorporated into FAR part 30.
Practical Implications
Contractors should not treat FAR part 30 as a standalone rule set; they must also review 48 CFR chapter 99 to understand the full CAS regime.
A common pitfall is assuming that a written accounting policy is enough—covered contractors must actually follow the disclosed practice consistently.
Changes in cost accounting practices can create compliance and pricing issues, so contractors should evaluate whether a proposed change triggers CAS consequences before implementation.
Contracting officers should verify CAS applicability early, because CAS coverage affects solicitation language, contract administration, and potential audit scrutiny.
Because this section incorporates the CASB framework by reference, disputes often arise from incomplete reading of the regulations rather than from the contract text alone.
Official Regulatory Text
(a) 41 U.S.C. chapter 15 , Cost Accounting Standards, requires certain contractors and subcontractors to comply with Cost Accounting Standards (CAS) and to disclose in writing and follow consistently their cost accounting practices. (b) Contracts that refer to this part 30 for the purpose of applying the policies, procedures, standards and regulations promulgated by the CASB pursuant to 41 U.S.C. chapter 15 , shall be deemed to refer to the CAS, and any other regulations promulgated by the CASB (see 48 CFR Chapter 99), all of which are hereby incorporated in this part 30 .