How to respond to a security questionnaire from your DoD prime

When a prime contractor sends you a security questionnaire, the instinct is often to work through it as quickly as possible and fill in the best answer you can from memory. That approach creates two problems: the answers may not accurately reflect your actual documented practices, and you have no record showing that someone responsible for your security reviewed and approved the response before it went out. Here's a better process.

Before you start: gather your documentation corpus

The single most important thing you can do before answering a single question is to locate the documents that should back up your answers. The core documents for a DFARS or CMMC-adjacent questionnaire are:

• Your System Security Plan (SSP). This is the authoritative record of your NIST SP 800-171 posture. Every question about access control, data protection, incident response, or configuration management should be answerable by reference to your SSP — either confirming you've implemented the control or noting it's in your POA&M.
• Your Incident Response (IR) Runbook. Questions about incident response procedures, especially the DFARS-required 72-hour reporting timeline, should be answered from your actual documented runbook — the specific version, the specific timeline commitments.
• Access control and data handling policies. Questions about how you manage user access, CUI handling, encryption practices, and data retention need to reference your actual policies, not your best recollection of them.
• Prior questionnaire responses. If you've answered similar questions for another prime or a previous annual review, those prior approved responses are useful source material — not to copy verbatim, but to confirm that your current answers are consistent with what you've said before.
• Your SPRS self-assessment and POA&M. Questions about your NIST 800-171 posture and any unimplemented controls should reference your SPRS assessment and your POA&M timeline.

Map questions to your existing documentation

Before drafting any answers, read through the entire questionnaire once and categorize each question by the type of documentation it's drawing on. Group access control questions together. Group incident response questions together. This prevents the situation where you give a slightly different answer to two questions that are asking about the same underlying practice.

For each question, identify the specific document and section that answers it. If no document covers the question, that's a signal either that you haven't implemented that control or that you have implemented it but haven't documented it. Both situations need to be handled accurately — not papered over with an optimistic yes.

Draft with citations — for every answer

When you draft your responses, write them as answers that reference their sources. Instead of:

"Yes, we encrypt all customer data at rest and in transit."

Write:

"Yes — data at rest is encrypted with AES-256 and data in transit uses TLS 1.2 or higher, per our Data Handling Policy §4.2 (rev 2024-Q3)."

The cited version gives your reviewer something to verify, gives your prime traceability to your documentation, and reduces the chance that you've overstated a control that your policy only partially covers.

For questions where your implementation is incomplete, cite your POA&M rather than deflecting: "Currently implementing — see our POA&M entry for control 3.1.x, with target completion Q3 2025." Primes who understand the CMMC landscape expect some controls to be in progress. An honest, documented gap is less concerning than a gap that surfaces later under scrutiny.

Your security team reviews before it goes out

The draft you've assembled from your documentation is not the final response. It needs to go through a review by the person on your team who owns the documentation being cited — not because the AI or the staff member drafting it made errors, but because the accountable reviewer is the person who can verify that the cited document actually says what the answer claims, and who takes responsibility for the response being accurate.

This step is not optional. Primes are asking about your security posture specifically so they have a documented record that they verified your controls. If your questionnaire response was assembled without security team involvement and something goes wrong later, that absence of review becomes part of the risk record. The security team sign-off is the mechanism that keeps the response accountable.

Your reviewer should: confirm that every cited document exists and is current, verify that the cited section actually supports the answer given, edit any answer where the draft overstates or understates your posture, and flag any question that requires a genuinely new answer — one that isn't covered by existing documentation — so it can be written from scratch with appropriate care.

Keep the audit trail

Once your security team has approved the response and you've sent it to your prime, preserve the record. Store the approved version of the questionnaire alongside the citations, the review history, and the date it was sent. Defense supply chain questionnaires often repeat on an annual cycle, and you may be asked to demonstrate consistency between years or to explain any changes in your answers.

An audit trail that shows the question, the answer, the source document cited, who reviewed it, when it was approved, and when it was exported is the documentation chain that holds up when your prime follows up. Without it, the only record is whatever the prime received — and that record is in their hands, not yours.