Since October 1, 2023, the FDA has enforced a Refuse to Accept (RTA) policy for premarket submissions that fail Section 524B requirements, consistent with its March 2023 RTA guidance and the 2026 Cybersecurity in Medical Devices guidance. Cybersecurity deficiency letters are common across submissions, and an RTA determination doesn’t just delay clearance. It signals that the submission did not meet statutory documentation requirements and may reflect deeper programmatic gaps in the manufacturer’s cybersecurity program. This is exactly where 524b compliance consulting provides critical value.
Most device makers already know 524B exists. The harder reality is that knowing the requirement and building documentation that satisfies an FDA reviewer are two very different things. The manufacturers who get through review cleanly aren’t necessarily the ones with the most sophisticated internal teams. They’re the ones who built their cybersecurity documentation the way reviewers expect to see it.
That’s where specialized 524b compliance consulting earns its value. Blue Goat Cyber has built its entire practice around medical device cybersecurity: every engagement is structured around the FDA’s actual expectations, not general cybersecurity best practices adapted for medical use. This article walks through what 524B requires, what reviewers scrutinize, the pitfalls that sink first-time submissions, and how to structure an engagement that holds up.
What Section 524B of the FD&C Act Actually Requires
The “Cyber Device” Definition and Why It Determines Your Obligations
Section 524B applies to any device that includes software validated, installed, or authorized by the sponsor, has the ability to connect to the internet, and contains technological characteristics that could be vulnerable to cybersecurity threats. That definition is broader than most manufacturers expect. Wearables, networked infusion pumps, diagnostic software, and embedded-firmware devices all fall under it.
The classification matters because it determines whether your 510(k), PMA, De Novo, or HDE submission must include a full 524B documentation package. If your device qualifies as a cyber device, there’s no exemption. The requirement applies to supplements as well, not just initial submissions.
The Three Statutory Obligations Under 524B(b)
The statute defines three distinct requirements, each mapping to specific documentation FDA expects in your submission. Misaligning documentation to the wrong subsection is itself a common deficiency trigger.
524B(b)(1) requires a plan to monitor, identify, and address postmarket cybersecurity vulnerabilities in reasonable timeframes, including coordinated vulnerability disclosure (CVD) procedures and patching timelines with justifications.
524B(b)(2) requires documentation of processes ensuring the device and related systems are cybersecure, including a Secure Product Development Framework (SPDF) and evidence of security architecture decisions.
524B(b)(3) requires a machine-readable Software Bill of Materials listing all commercial, open-source, and off-the-shelf software components.
FDA ties all three to “reasonable assurance of cybersecurity.” An unmet requirement isn’t a minor gap reviewers overlook; it’s grounds for denying premarket authorization.
The Submission Artifacts FDA Reviewers Scrutinize
SBOM: Format, Depth, and What Incomplete Looks Like
The SBOM must be machine-readable. A PDF table doesn’t meet the requirement. Per the FDA’s 2026 Cybersecurity in Medical Devices guidance, the FDA accepts SPDX and CycloneDX formats, and submissions should include both a machine-readable version in JSON or XML and a human-readable companion document. Every component needs supplier name, component name, version, unique identifier (Package URL or CPE), dependency relationships, SBOM author, and timestamp.
Completeness means all components, including nested dependencies. Reviewers cross-reference SBOM data against known vulnerability databases, so a stale SBOM with unaddressed CVEs doesn’t just look sloppy. It signals that the manufacturer’s security controls aren’t operational. Increasingly, reviewers also expect exploitability scores and patching plans tied to individual SBOM entries, not just an inventory list. For a practical primer on how the FDA understands Section 524B and SBOM expectations, see this overview of FDA Section 524B.
Vulnerability Management Plan: What the Document Must Cover
FDA guidance references specific operational commitments, including 30-day notification and 60-day remediation windows for critical risks, along with documented justifications for any deviations from those windows. Plans that describe intent without those specifics attract deficiency letters. A credible vulnerability management plan names the monitoring sources (NVD, ICS-CERT), defines timelines for critical versus non-critical response, documents CVD procedures, and describes patch delivery mechanisms.
The plan also needs to account for fielded devices, not just newly manufactured units. Devices still in clinical use but no longer actively marketed require separate documentation from currently marketed units. Reviewers will look for that distinction.
For clarifications on FDA expectations and frequently asked questions about cybersecurity in medical devices, consult FDA’s cybersecurity FAQs.
Security Architecture and Penetration Testing Reports
The FDA expects security architecture documented as a design artifact: interface diagrams, trust boundaries, and data flow documentation. A narrative description of security features in the submission narrative doesn’t substitute for structured architectural documentation.
Penetration testing reports must tie directly to the threat model. Findings need to show how identified vulnerabilities were resolved or formally risk-accepted, with evidence. A report that lists findings without remediation traceability reads as incomplete, and reviewers will follow up.
Common Pitfalls That Derail 524B Premarket Submissions
Treating the SBOM as a Static Document
Many manufacturers generate an SBOM during development and submit it unchanged, without updating it to reflect late-stage component changes or patches applied before filing. That creates an immediate credibility problem. If the submitted SBOM doesn’t match the device’s actual software composition at the time of submission, reviewers have no confidence the postmarket monitoring plan is based on accurate data.
The fix is procedural: SBOM maintenance needs to be a controlled activity tied to your change management process, updated at each Engineering Change Order (ECO) sign-off, not a one-time export from a build tool.
Underbuilt Postmarket Monitoring Plans
One of the most consistent gaps in first-time 524B submissions is a vulnerability management plan that reads as aspirational rather than procedural. No defined monitoring sources, no named responsible roles, no documented escalation paths. FDA reviewers aren’t evaluating intentions; they’re evaluating whether the plan describes a real operating procedure.
Plans that fail the 524B(b)(1) bar will surface as a deficiency regardless of how strong the rest of the submission is. A weak monitoring plan can hold up an otherwise complete package.
Disconnected Security Documentation and the Quality System
524B requires that cybersecurity practices be integrated into the device’s quality system. Cybersecurity documentation built in a silo, without connection to design controls, risk management files, and postmarket surveillance processes, creates obvious structural gaps. Reviewers are trained to look for those seams.
This is one of the more subtle failure modes, because the documentation can look complete in isolation. The problem only becomes visible when a reviewer tries to trace a threat model finding through to the risk management file and finds no connection.
How Full-Service 524B Compliance Consulting Closes These Gaps
What a Full-Service Engagement Actually Covers
A comprehensive 524b compliance consulting engagement starts with a gap assessment against current FDA guidance, informed by key premarket cybersecurity requirements, then moves through threat modeling, SBOM generation and tooling setup, penetration testing, vulnerability management plan development, SPDF documentation, and eSTAR-ready submission packaging. For most devices, a full engagement spans several months, with the gap assessment and initial documentation phase often requiring one to two months and subsequent phases, including penetration testing and submission packaging, adding additional time depending on device complexity and quality system maturity. Simple, lower-risk devices may move faster; legacy device remediation typically takes longer.
The real value isn’t just document production. It’s having experienced consultants build documentation structured exactly the way reviewers expect to see it. That institutional knowledge is hard to replicate internally, especially for manufacturers preparing their first cyber device submission.
Why Blue Goat Cyber Is Built for This Work
Blue Goat Cyber focuses exclusively on medical device cybersecurity. Every engagement is structured around FDA submission requirements from the start, not adapted from enterprise IT security practice. That distinction matters because the documentation standards, threat modeling frameworks, and SBOM tooling decisions that work for FDA submissions are specific to that context.
The firm’s capabilities map directly to 524B’s requirements: SBOM development with the right formats and depth, penetration testing tied to device-specific threat models, SPDF documentation integrated into quality systems, postmarket vulnerability management frameworks, and deficiency response support when submissions need course correction. Manufacturers working with Blue Goat Cyber get submission-ready documentation without building internal cybersecurity expertise from scratch or absorbing the cost of a rejected submission. Manufacturers can also review our medical device cybersecurity best practices.
What to Expect from Timeline and Engagement Structure
For a new device with no existing cybersecurity documentation, a realistic full-service 524b compliance consulting engagement typically spans six to twelve months from gap assessment through final submission package, depending on device complexity and the manufacturer’s existing quality system maturity. Legacy device remediation takes longer. Compensating controls, fielded-device documentation, and the added scope of securing already-cleared products mean manufacturers with older devices should build that additional time into their planning.
Postmarket obligations also start before clearance, not after. Consultants who understand this build the operational scaffolding alongside the premarket documentation, not as a separate phase.
A Practical 524B Compliance Checklist Before You Submit
Premarket Documentation Readiness
Before filing, verify that every required artifact is present and internally consistent:
- Machine-readable SBOM (SPDX or CycloneDX) with all components, versions, dependency data, and known CVEs addressed with patching plans
- Threat model aligned with device architecture, connectivity, and clinical use environment
- SPDF documentation integrated into the quality system with traceability to design controls
- Penetration test report with threat model traceability and remediation evidence for all findings
- Security architecture documentation including interface diagrams, trust boundaries, and data flows
- Vulnerability management plan with specific timelines, named roles, monitoring sources, and CVD procedures
- eSTAR-compatible formatting with section mapping confirmed against current FDA submission template requirements
Postmarket Readiness Before Clearance
524B obligations don’t end at submission. Manufacturers need live monitoring processes, patch delivery mechanisms, and documented disclosure procedures operational before the device reaches market. A postmarket cybersecurity plan that exists only on paper, without supporting tooling, staffing, and operational procedures, is a deficiency waiting to happen.
This is where many manufacturers underestimate the scope of the requirement. Documenting a plan and running a plan are two different things. Reviewers increasingly probe whether the described processes are supported by actual tooling, staffing, and operational procedures.
The Practical Path to a Cleared Cyber Device
Section 524B compliance isn’t optional complexity layered onto an already demanding submission process. It’s a prerequisite for FDA authorization of any cyber device, and the documentation bar is specific enough that gaps in first-time submissions are common. The manufacturers who navigate it cleanly build documentation that reflects real operational processes, get their SBOM right before submission, and connect their cybersecurity program to their quality system in ways reviewers can trace.
The core actions are clear: determine whether your device qualifies, build documentation that reflects actual procedures rather than aspirational ones, maintain your SBOM as a living artifact, and integrate cybersecurity into your quality system from the start rather than attaching it at the end.
If you’re preparing your first 524B-compliant submission or inheriting a program with documentation gaps, 524B compliance consulting services from a specialized firm like Blue Goat Cyber offer the fastest path to clearance without the cost of building that expertise in-house. Deficiency cycles are expensive and avoidable.
Related: Medical Device Cybersecurity: A Complete Lifecycle Guide