How Prime Contractors Are Screening Subcontractors in 2026

Executive Brief 

Prime contractors are no longer waiting for formal enforcement timelines to manage cyber risk. 

This year in 2026, subcontractor screening shifts from informal questionnaires to structured, evidence-based evaluations tied directly to Cybersecurity Maturity Model Certification (CMMC) readiness. 

Prime contractors are actively assessing whether subcontractors can protect Controlled Unclassified Information (CUI), support compliant environments, and withstand audit scrutiny. 

Dig deeper below to learn what primes are looking for, how screening has evolved, and what subcontractors should be doing now to stay eligible. 

Why Prime Contractor Screening Has Tightened 

CMMC 2.0 is no longer theoretical. 

With the CMMC rule finalized under Title 32 of the Code of Federal Regulations (32 CFR) Part 170 and contract clauses expected through the Defense Federal Acquisition Regulation Supplement (DFARS), primes are under pressure to reduce supply chain risk. 

Key drivers behind stricter screening include: 

• Increased liability tied to subcontractor cyber failures 

• Department of Defense (DoD) (also known as the Department of War) enhanced flow-down accountability measures 

• Limited availability of Certified Third-Party Assessment Organizations (C3PAOs) 

• Program risk tied to delays caused by noncompliant suppliers 

Prime contractors are responding by setting their own readiness thresholds, often ahead of formal deadlines. 

What Prime Contractors Are Evaluating in 2026 

Subcontractor screening now focuses on proof, not promises. 

Common evaluation criteria include: 

CMMC Level Alignment 

• Confirmation of required CMMC level based on data handled 

• Evidence of readiness for Level 2 where CUI is involved (i.e. proof of certification or scheduled assessment date) 

• Clear understanding of whether third-party assessment is required 

Supplier Performance Risk System (SPRS) Scores 

• Current SPRS score submission 

• Alignment between score, System Security Plan (SSP), and evidence 

• Realistic Plans of Action and Milestones (POA&Ms), not aspirational ones 

Scope and Architecture Decisions 

• Defined CUI boundaries and data flows 

• Use of enclaves or segregated environments 

• Clear ownership of shared or inherited controls 

Governance and Accountability 

• Documented policies and procedures 

• Role separation and access controls 

• Evidence of continuous monitoring, not one-time fixes 

Primes are looking for subcontractors who understand their environment and can defend it under assessment. 

Early Screening Is Becoming the Norm 

Many prime contractors are not waiting for a contract clause to require proof. 

They are: 

• Requesting readiness artifacts during supplier onboarding 

• Conditioning awards on demonstrated progress 

• Limiting the amount of CUI or sensitive work assigned to subcontractors with unclear readiness 

• Replacing suppliers who cannot show a credible compliance path 

This is why early adopters are gaining an advantage. 

Organizations that can clearly articulate their CMMC posture are easier to approve, onboard, and retain. 

Tracking What Primes Are Saying About CMMC 

Prime contractors are increasingly transparent about their expectations. 

That information, however, is scattered across supplier portals, guidance documents, and public statements. 

ISI created this CMMC Prime Tracker page to centralize this insight. 

The page aggregates publicly available communications from leading prime contractors and highlights how they are approaching: 

• Early CMMC certification expectations 

• Subcontractor flow-down requirements 

• Risk-based screening decisions 

See what your prime contractor is saying about CMMC. 

This resource helps subcontractors anticipate requirements before they become contractual.

What Subcontractors Should Be Doing Now 

To remain competitive this year in 2026, subcontractors should focus on: 

• Aligning CMMC scope to actual CUI handling 

• Scheduling their Level 2 (C3PAO) assessment 

• Maintaining an accurate SSP and defensible SPRS score 

• Understanding which controls can be inherited and which cannot 

• Preparing for prime contractor audits and data calls 

• Monitoring prime-specific guidance, not just DoD rules 

CMMC readiness is now a business development issue, not just a compliance one.

FAQs 

Are prime contractors allowed to require CMMC early?

Yes. Prime contractors retain discretion to impose cybersecurity requirements on subcontractors as part of supplier risk management, even before formal DoD enforcement dates. 

Can a subcontractor rely on a prime’s certification?

Only in limited cases. Unless you operate entirely within the prime contractor’s controlled and documented environment, responsibility for compliance remains with the subcontractor. 

Do SPRS scores still matter once CMMC is enforced?

Yes. SPRS scores remain a screening and risk signal for primes, especially during interim periods and supplier evaluations. 

What happens if a subcontractor cannot meet a prime’s requirements?

Primes may reduce scope, delay awards, or replace suppliers to protect program timelines and compliance posture. 

How can subcontractors stay ahead of changing expectations?

Monitor prime contractor communications, track public guidance, and align internal readiness efforts accordingly. Working with an expert partner can also help reduce your team’s effort on staying up-to-date on changing regulations. 

Internal Links 

• CMMC Requirements for Subcontractors: What You Need to Know 

• DCSA Vulnerability Assessments: How to Know If You’re Ready 

• CMMC 48 CFR Goes Into Effect: What Contractors Should Do Now 

• SPRS Scores Vs. CMMC Certification: What Contractors Need in 2025