Best Cybersecurity Assessment Providers Serving the US Defense Sector
The US defence industrial base is being asked to prove its cybersecurity rather than assert it. CMMC is now a condition of contract award for organisations handling Controlled Unclassified Information, and the practical effect is that tens of thousands of contractors and subcontractors need two different things from two different kinds of firm: help getting ready, and an accredited assessment.
Those are not the same service, and confusing them is the most common and most expensive mistake in this market. A Certified Third Party Assessment Organisation, or C3PAO, is authorised by the Cyber AB to perform the assessment that results in certification. A readiness or advisory firm helps you find and close the gaps before that assessment happens. A C3PAO cannot consult its way through your gaps and then certify you against them, so most contractors end up engaging both.
This article covers the providers in our directory that serve the US defence sector, with what each one actually holds set out plainly. Where a firm is accredited we say by whom, and where a firm does readiness work rather than assessment we say that too.
What to check before you sign anything
- Whether the firm is on the Cyber AB Marketplace, and in what role. Only a C3PAO can perform the certification assessment. Registered Provider Organisations are advisory, and a firm may legitimately be neither while still doing good readiness work.
- Whether they have done NIST SP 800-171 work at your level. Level 2 means 110 controls with evidence behind each one. Level 3 adds NIST SP 800-172.
- Whether penetration testing is included or sold separately. CMMC practice CA.L2-3.12.1 requires periodic assessment of control effectiveness, and testing is the most direct way to evidence it.
- Whether the enclave you are certifying is scoped realistically. Most cost overruns come from scoping the whole business instead of the systems that touch CUI.
- Whether your assessor is independent of whoever did your remediation.
SBS CyberSecurity
Featured partner
SBS CyberSecurity is a Madison, South Dakota firm founded in 2004, and its centre of gravity is regulated financial institutions: community banks and credit unions, plus the state banking associations that endorse it. It is a Platinum Member of the American Bankers Association Partner Network and has preferred provider relationships across more than 20 state banking associations.
For defence contractors it offers CMMC readiness at Level 1 and Level 2: gap identification, documentation, and preparation that carries straight into assessment by a Certified Third Party Assessment Organisation.
What it brings to a defence engagement is a governance-first method built for examined industries. Banks have lived under continuous regulatory examination for decades, and the reporting model SBS uses, a prioritised action plan aimed at a board rather than a raw findings dump, transfers cleanly to a CMMC readiness programme. Penetration testing covers external network, internal network, web application, wireless, and PCI DSS Requirement 11, aligned to NIST, OWASP and PTES, and the firm also runs red team, purple team and social engineering assessments, virtual CISO, and NIST Cybersecurity Framework assessments.
Its published case studies show that depth in banking. For an accredited assessor, or a defence-specific testing track record, the entries below cover that ground.
A-LIGN
A-LIGN is the only authorised CMMC C3PAO in this directory, and it also holds FedRAMP 3PAO authorisation, HITRUST Authorized Assessor status, and PCI QSA. That combination matters for a contractor that needs a federal assessment and a commercial one from the same firm without running two procurement processes.
Because A-LIGN can perform the certification assessment, the sequencing question applies: independence rules mean the firm that remediates your gaps should not be the firm that certifies you against them. Most contractors use a readiness partner first and bring in a C3PAO for the assessment.
SpecterOps
Based in Alexandria, Virginia, SpecterOps is an adversary simulation specialist with a genuine research reputation, and the company behind BloodHound, which is standard equipment for Active Directory attack path analysis. For a defence contractor with a mature security programme, this is red teaming that tests detection and response rather than producing a vulnerability list.
Mandiant
Mandiant, in Reston, Virginia, brings incident response and threat intelligence depth that few firms can match, alongside FedRAMP 3PAO authorisation, SOC 2 and ISO 27001. The natural fit is a contractor that wants adversary emulation informed by current intrusion data, or that needs response capability retained before it is needed.
Coalfire
Coalfire holds FedRAMP 3PAO authorisation, PCI QSA, SOC 2 and ISO 27001, and works across CMMC and the wider federal compliance estate. For contractors pursuing FedRAMP authorisation alongside CMMC, consolidating both with one firm removes a lot of duplicated evidence gathering.
Schellman
Schellman is a large assessment firm holding FedRAMP 3PAO, PCI QSA, SOC 2 and ISO 27001, with CMMC among its compliance coverage. Its strength is breadth of assessment capability under one roof, which suits contractors carrying several compliance obligations at once.
GuidePoint Security
GuidePoint, in Reston, Virginia, combines FedRAMP 3PAO authorisation, PCI QSA, SOC 2 and ISO 27001 with a substantial federal practice. It suits contractors that want assessment and ongoing security operations from the same relationship rather than splitting them.
Praetorian
Praetorian, based in Austin, Texas, is an offensive security firm covering CMMC alongside its testing practice, with a strong engineering reputation. The fit is a contractor that wants technically deep offensive testing to evidence control effectiveness, rather than a compliance-led engagement.
TrustedSec
TrustedSec, in Fairlawn, Ohio, holds PCI QSA and covers CMMC, and is well regarded for practitioner-led testing and for the research its consultants publish. A good fit where you want testers who are visible in the community and a report your engineers will act on.
Synack
Synack, in Redwood City, California, holds FedRAMP 3PAO authorisation and SOC 2, and delivers testing through a vetted researcher network on a continuous model. This suits contractors that want testing running against a changing estate rather than an annual point-in-time engagement.
How to use this list
If you need certification, start with a C3PAO, which in this directory means A-LIGN. If you need to be ready for that assessment, a readiness partner is the right first call, and SBS CyberSecurity is our featured partner for that work. If your gap is technical rather than documentary, the offensive specialists here will tell you faster whether your controls actually hold.
Our full methodology is published at how we rank, and every provider profile lists the sources behind its claims.
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