The Cost Accounting Standards (CAS) regime is undergoing its most significant modernization effort since its inception in the 1970s, moving the defense industry toward being more aligned with commercial approaches. Recent actions by the Cost Accounting Standards Board (CASB or Board), the National Defense Authorization Act for fiscal year 2026’s (NDAA) significant revisions to CAS coverage and certified cost or pricing data thresholds, and a series of Department of War (DoW) reform initiatives collectively signal a broader policy shift away from Government-unique accounting requirements and toward greater reliance on Generally Accepted Accounting Principles (GAAP), existing commercial financial-control frameworks such as Sarbanes-Oxley (SOX) compliance environments, and market-based acquisition approaches.

For government contractors, these developments extend beyond the rescission of accounting standards. They reflect a fundamental reassessment of how the Government oversees contractor accounting systems, financial controls, and contract-costing practices. Viewed together, the CASB rulemakings, NDAA reforms, and DoW modernization initiatives suggest an emerging policy preference for relying on mature commercial accounting and control frameworks where they provide protections comparable to Government-unique requirements. If that trend continues, contractors may see a future compliance environment that places greater emphasis on commercial accounting practices and internal controls while retaining targeted Government oversight in areas unique to federal contracting. In part 1 of this series, we will discuss what has changed and why it matters to defense contractors. Part 2 of the series will then explore what may be coming down the road and how to be prepared.

What Has Changed?

CAS 404, 408, 409, + 411

The first major development occurred on July 8, 2026, when CASB issued a final rule rescinding two Cost Accounting Standards in their entirety (CAS 408, 411) and substantially eliminating two others (CAS 404 and 409).

CASB explained that this action eliminates 68 of the 72 individual requirements and removes more than 10,000 words of regulatory text. The Board concluded that modern GAAP, together with existing CAS consistency standards, allocation standards, FAR cost principles, and CAS contract clauses, adequately protects the Government’s interests in these areas. As a result, maintaining separate Government-specific accounting requirements for capitalization, depreciation, material accounting, and compensated absences was no longer considered necessary.

CAS 407: The Trend Continues

CASB continued this effort on September 1, 2026, by issuing a final rule rescinding CAS 407, Use of Standard Costs for Direct Material and Direct Labor, effective October 1, 2026. The Board concluded that most of CAS 407 substantially overlapped with GAAP, Disclosure Statement requirements, existing CAS standards, and FAR cost principles. Rather than maintaining a largely duplicative standard, CASB rescinded CAS 407 and retained only limited provisions governing production-unit accounting and variance allocation by relocating those requirements to CAS 418.

The retained CAS 407 provisions concern “production units,” which are groupings of similar activities that use homogeneous inputs or produce homogeneous outputs. CASB concluded that these requirements remain necessary because they affect the allocation of cost variances among contracts, an area not directly addressed by GAAP. The Board’s treatment of CAS 407 is particularly notable because it illustrates the broader distinction between cost measurement and cost allocation that increasingly appears to be guiding CAS modernization efforts.

CAS Coverage + Threshold Reforms

The recent CASB rulemaking has also occurred alongside broader efforts to reduce the scope and burden of Government-unique accounting requirements. In a separate final rule also issued on September 1, 2026, CASB implemented the NDAA’s increase in the full CAS coverage threshold from $50 million to $100 million and simplified the CAS coverage framework by increasing the CAS applicability threshold to $35 million and eliminating the historical $7.5 million trigger-contract mechanism. For many contractors, the practical effect is that CAS will apply less frequently and contractors that remain subject to CAS are more likely to fall under modified rather than full CAS coverage.

These changes reduce the number of contractors subject to CAS and concentrate modified and full CAS coverage among larger participants in the defense industrial base. The NDAA also increased the threshold for certified cost or pricing data from $2.5 million to $10 million, further reducing compliance obligations associated with negotiated procurements. These threshold changes also have the effect of separating further CAS coverage from certified cost or pricing data requirements, creating a broader range of procurements that may be subject to one regime but not the other. To maintain compliance, contractors need to assess internal proposal, pricing, and compliance procedures as these requirements become less closely aligned.

The September 2026 implementation rule also streamlined certain Disclosure Statement requirements, established transition procedures for some contractors moving from full to modified CAS coverage, and clarified the application of CAS thresholds and exemptions to indefinite-delivery contracts. These changes reflect a broader effort to reduce not only substantive accounting requirements, but also the administrative burdens associated with CAS coverage, disclosures, and compliance administration.

Together, these reforms reflect a broader policy objective of concentrating oversight on larger contractors and higher-risk procurements while making federal contracting more accessible to commercial and emerging companies. Further, these actions demonstrate that CASB is not eliminating CAS as a concept. Rather, the Board is increasingly removing requirements that substantially overlap with mature commercial accounting standards while preserving those requirements it believes remain necessary to ensure consistency, transparency, and equitable allocation of costs among Government contracts.

Why These Changes Matter

The significance of these reforms extends beyond the elimination or substantial revision of several Cost Accounting Standards and related CAS coverage and administration requirements. Collectively, they represent a shift in regulatory philosophy consistent with other changes in acquisition made in the last year.

For decades, contractors often maintained accounting analyses, documentation, and compliance procedures designed to satisfy both CAS and GAAP requirements, even when the underlying accounting principles were substantially similar. This duplication increased compliance costs, audit effort, and administrative complexity while often providing limited additional value. The recent CASB rulemaking acknowledges that commercial accounting standards, external financial statement audits, and modern corporate governance frameworks now perform many of the functions that CAS originally addressed.

The changes may reduce compliance burdens by:

  • Simplifying accounting policies and procedures.
  • Reducing documentation requirements.
  • Decreasing the need for parallel CAS and GAAP analyses.
  • Limiting interpretive disputes involving overlapping accounting guidance.
  • Lowering the administrative costs associated with maintaining compliance infrastructures.

Perhaps most importantly, the rulemaking reflects a willingness among policymakers to reevaluate legacy regulatory requirements in light of significant advances in financial accounting standards, auditing practices, enterprise resource planning (ERP) systems, and corporate governance frameworks. Rather than assuming that long-standing Government-specific requirements remain necessary, the Board has signaled a greater willingness to assess whether commercial standards can effectively achieve the same objectives.

The DoW Signals Additional CAS Reform

The DoW’s September 14, 2026 memorandum, “Fostering One Strong Industrial Base,” directs a series of acquisition and contract-accounting reforms intended to further reduce Government-unique compliance requirements and expand the defense industrial base. Most notably, the memorandum states that the Department intends to move from Government-unique Cost Accounting Standards to GAAP-based accounting “to the maximum extent the law permits” and to continue pursuing additional CAS-to-GAAP conformance through the CASB.

The memorandum directs the Department to develop proposals that would make CAS exemption the default, confine remaining CAS coverage to limited categories of sole-source, cost-based development, or incentive-fee procurements, ensure that CAS applies only to relevant contracts and indirect-cost pools rather than entire companies, and modernize Disclosure Statement requirements. If adopted, those reforms would represent one of the most dramatic reductions in the scope of CAS coverage since the standards were first implemented.

The memorandum also reinforces a broader preference for market-based acquisition approaches. Consistent with recent acquisition reform initiatives, the Department states that cost-based contracting should generally be reserved for situations where adequate market pricing does not exist, while fixed-price and commercially oriented acquisition approaches should remain the default wherever possible. To the extent the Government relies less frequently on cost-based procurement methods, the significance of Government-unique cost-accounting requirements may diminish as well, further reinforcing the Department’s stated objective of reducing reliance on specialized accounting frameworks in favor of commercial standards and practices.

The September 2026 memorandum builds on the Department’s earlier August 18, 2026 memorandum, “Supplier Cost and Pricing Transparency,” which emphasized continued Government access to cost and pricing information in support of pricing decisions and acquisition oversight. It also follows the Department’s July 31, 2026 request for stakeholder input on accounting, audit, and business system reform. Taken together, the memoranda suggest that the Department seeks to reduce Government-unique accounting frameworks while continuing to obtain visibility into contractor cost information when necessary to promote transparency and fair pricing.

The memorandum further directs substantial reform of contractor business-system oversight, increased reliance on commercial accounting and financial-control frameworks, and greater consideration of audited financial statements and internal-control attestations in lieu of duplicative Government reviews.

Whether all of these reforms are ultimately adopted remains uncertain. Several proposals outlined in the memorandum would require implementation through future rulemaking and may raise questions regarding how the Department’s policy objectives interact with existing statutory and regulatory CAS requirements. For example, the memorandum contemplates making CAS exemption the default and substantially narrowing the circumstances in which CAS applies, while Congress only recently revised the statutory framework governing CAS applicability and coverage through the NDAA for FY 2026. How those proposals would ultimately be reconciled with existing statutory requirements will likely be a critical issue as implementation efforts proceed. Nevertheless, the memorandum provides the clearest indication to date that recent CAS rulemakings may represent only the beginning of a broader effort to reduce Government-unique accounting requirements and rely more heavily on commercial standards and practices.

CASB 2026 Reforms and Their Broader Implications

The CASB’s 2026 rulemakings represent the most significant narrowing of the Cost Accounting Standards framework in decades. By rescinding CAS 407, CAS 408, and CAS 411, substantially eliminating CAS 404 and CAS 409, and implementing significant CAS threshold reforms, the Board has taken a meaningful step toward aligning contractor accounting requirements with modern commercial accounting practices.

Importantly, the reforms do not eliminate CAS as a regulatory framework. Instead, they reflect a distinction that may shape future modernization efforts: while GAAP increasingly serves as the primary source of guidance for measuring and recognizing costs, CAS continues to play a critical role in ensuring consistency and the equitable allocation of costs among Government contracts.

The broader significance of these recent reforms may be less about the immediate accounting changes they produce and more about the precedent they establish. In part 2 of this series, the discussion will turn to what may be coming in the next round of reforms and what organizations can do to respond to the changes. For contractors seeking support in this transition, Fluet’s Government Contracts Practice offers experience in CAS compliance and regulatory adaptation.