Cost Accounting Standards Update: What Federal Contractors Should Review

Last reviewed: July 29, 2026  |  Rule effective: August 7, 2026

This Cost Accounting Standards update addresses a final rule that eliminates much of four longstanding standards and relies more heavily on Generally Accepted Accounting Principles, or GAAP. Effective August 7, 2026, the Cost Accounting Standards Board will fully rescind CAS 408 and 411, rescind most of CAS 404 and 409, and relocate four retained requirements to CAS 405.

The rule reduces duplication, but it does not eliminate CAS, contractor disclosure responsibilities, consistency requirements, cost-allocation controls, or the need to align estimating and accounting practices. For many contractors, the immediate work will be a disciplined review—not a wholesale change in accounting. Companies that need help evaluating their affected practices can review GDIC’s federal financial compliance services.

What Did the Cost Accounting Standards Board Change?

The July 8 final rule affects four standards covering tangible assets, compensated absences, depreciation, and material acquisition costs. The Board determined that GAAP, other Cost Accounting Standards, and applicable FAR cost principles now protect most of the same government interests.

The official CAS Board final rule removes 68 of the 72 combined individual requirements in these four standards and more than 10,000 words of regulatory text. Those figures describe the affected standards; they do not mean that 68 of all CAS requirements or most of the entire CAS framework have disappeared.

Why Were CAS 404, 408, 409, and 411 Rescinded?

The standards were adopted between 1973 and 1975, when commercial accounting rules did not address these cost-measurement issues as comprehensively as they do now. Over time, GAAP developed substantially while much of the corresponding CAS text remained unchanged.

The Board concluded that GAAP now provides substantially equivalent treatment in most of the four areas. Remaining CAS consistency and allocation standards, applicable contract clauses, and FAR cost principles continue to protect the government against inconsistent practices and increased costs caused by contractor accounting changes. The objective is therefore to remove overlapping rules, not to weaken the underlying requirement for supportable and consistently applied practices.

Does This Cost Accounting Standards Update Eliminate CAS Compliance?

A contractor should continue to determine coverage from the solicitation, contemplated award, applicable exemptions, prior CAS-covered awards, and the clauses incorporated into the contract. A company should not determine CAS applicability from a news summary, its revenue, or the value of one opportunity alone.

The current FAR Part 30 and 48 CFR Part 9903 contract-coverage rules remain the starting points for evaluating whether a negotiated contract is exempt and whether full or modified coverage applies.

Who Is Most Directly Affected?

The rule is most directly relevant to business units with CAS-covered contracts that use the affected practices, including contractors maintaining disclosure statements and companies preparing for awards that may include CAS clauses. It is also important to commercial and nontraditional firms entering larger negotiated federal procurements and to growing contractors approaching the transition from small-business status.

Does the Final Rule Apply to Small Businesses?

Small businesses may still have a strategic reason to understand the change. A company may outgrow its size standard, acquire another business, compete through a non-small affiliate or segment, or pursue future contracts under a different status. CAS exemption also does not remove separate FAR cost principles, solicitation-specific accounting-system requirements, or the obligation to support proposed and billed costs when those requirements apply.

Should Contractors Change Their Accounting Practices?

Contractors should not change an accounting practice solely because a CAS citation was rescinded. For CAS 404, 409, and 411, the Board does not expect the final rule itself to require a change in compliant practices because the relevant CAS and GAAP treatments are already substantially aligned.

A voluntary change made after the rule takes effect may still be treated as a unilateral accounting-practice change, with disclosure, notification, and cost-impact consequences. The fact that a former CAS provision is no longer present does not automatically make a later practice change “required.”

CAS 408 requires special attention. GAAP may recognize certain compensated-absence costs in an earlier period than CAS 408 permitted. The final rule exempts changes directly associated with CAS 408 conformance from the normal contract price and cost-adjustment requirements, but the change must be disclosed and made during the contractor’s fiscal year directly following the rule’s effective date. Contractors should document the analysis connecting any transition specifically to CAS 408 conformance.

What Should Federal Contractors Review Now?

A useful implementation review should trace the change through the contractor’s complete operating record. Removing outdated citations from one policy is not enough if the disclosure statement, estimating manual, enterprise system, proposal template, and training materials still rely on different assumptions.

Contractors preparing for audit or system review should connect this work to broader federal financial compliance audit readiness. The strongest record is one that shows not only what the contractor decided, but also which contracts, practices, documents, and systems were reviewed and who approved the conclusion.

How Does the Rule Affect Federal Cost Proposals?

The rule does not rewrite a solicitation’s pricing instructions, but it can affect the references and supporting logic used in cost proposals. Estimating practices must remain consistent with applicable disclosed or established accounting practices, and proposed costs must still be traceable, supportable, and responsive to the solicitation.

GDIC’s federal proposal services can be coordinated with compliance and pricing review so the technical approach, staffing model, basis of estimate, cost narrative, and accounting treatment form one supportable submission.

What Should Contractors Complete Before and After August 7?

What Mistakes Should Contractors Avoid?

• Interpreting the rule as the elimination of CAS.
• Assuming all federal contractors, including small businesses, are directly subject to the change.
• Changing an accounting practice without determining whether the change is required, unilateral, or otherwise subject to disclosure and cost-impact procedures.
• Removing CAS 404 and 409 references without preserving the four requirements relocated to CAS 405.
• Treating a CAS 408 transition as automatically exempt without documenting its direct connection to GAAP conformance and following the timing requirement.
• Updating the accounting policy but leaving conflicting disclosure, estimating, ERP, proposal, or training records in place.
• Combining the July final rule with separate CAS threshold and IDIQ proposals as though they were one final action.
• Allowing the proposal team to rely on obsolete citations or methods that no longer match approved accounting practices.

Is This Part of a Broader CAS Modernization Effort?

Yes. The July rule is one part of a broader effort to conform CAS to GAAP, reduce unnecessary transaction costs, clarify coverage, and lower barriers for commercial and nontraditional contractors. The CAS Board’s 2026 agenda also addresses CAS 407, 415, and 416; monetary thresholds; CAS treatment of indefinite-delivery contracts; and the cost impact of accounting changes.

Those matters do not all have the same legal status. Some are proposed rules or continuing Board work and should not be presented as part of the final rule effective August 7. Contractors should monitor the official CAS Board agenda and rulemaking and evaluate each final action separately.

How Does GDIC Support CAS Readiness and Proposal Alignment?

GDIC’s Federal Financial Compliance team supports contractors with CAS disclosure and compliance reviews, cost-accounting practice assessments, mock business-system reviews, policy development, internal-control testing, incurred-cost support, and corrective-action planning. The work can be scoped to this final rule or incorporated into a broader audit-readiness and financial-compliance review.

GDIC can also connect compliance analysis with capture services, pricing, and proposal development. That integration is useful when a contractor is preparing for a complex negotiated procurement and must ensure that its capture assumptions, staffing approach, estimating methods, cost volume, and accounting practices are consistent before submission.

The Practical Takeaway

The August 7 rule is a meaningful reduction in duplicative regulation, but it is not a release from disciplined cost accounting. CAS-covered contractors should determine where the four affected standards appear in their operating record, preserve the requirements relocated to CAS 405, evaluate any CAS 408 transition, and document whether established practices remain unchanged.

The most defensible implementation connects accounting, disclosure, internal controls, estimating, and proposal preparation. That approach allows the contractor to benefit from a simpler regulatory framework without creating avoidable inconsistencies, unsupported accounting changes, or proposal risk.