FedRAMP High: Requirements and readiness

Teams pursuing FedRAMP High face the strictest version of the US federal government’s security framework. It enforces the most stringent controls, the strongest hardening expectations, and continuous monitoring with no room for drift. Typically, teams begin at Medium and then transition to High, only to discover that the gap between the two is substantial. FedRAMP High also comes with a corresponding operational load increase, as failures at this level can lead to mission failure, widespread public impact, and significant harm.

If you already know the basics, as covered in our FedRAMP Compliance article, this guide focuses on what shifts at the High baseline. We’ll cover the requirements, the common bottlenecks, and the practical measures that keep High-impact environments stable and audit-ready. If you’re new to FedRAMP or would like a foundational overview, start with the guide first.

What is FedRAMP High?

FedRAMP assigns every cloud service to one of three baselines: Low, Moderate, or High. The designation is based on the potential harm that could result if the service’s security controls fail. For teams preparing for High, the baseline shift is significant: the threat model assumes immediate operational stakes, and the control set expands accordingly.

FedRAMP High is built for workloads where confidentiality, integrity, or availability failures would have severe consequences, including high-stakes mission failure, major operational impact, law-enforcement risk, financial harm, or widespread public impact.

Which organizations need FedRAMP High authorization?

If the agency categorizes its data as requiring Federal Information Processing Standards (FIPS) 199 High compliance, any supporting cloud service must also meet FedRAMP High standards. Additionally, any systems where downtime or data loss would materially affect operations or public safety will also need a High authorization. The requirement is tied to the sensitivity and impact level of the data you handle, regardless of the size of your company or the volume of data you’ll have to process.

Typically, this category will include:

• Benefits, healthcare, and identity platforms operating at a national scale. They process PII data that requires FedRAMP High’s confidentiality and availability guarantees.

• Tools that support federal investigations and incident response. These are aligned with High-impact enforcement workloads under FIPS-199.

• Cloud infrastructure for defense or homeland security workloads. Typically, these end up mapped to High due to mission continuity requirements.

• Analytics, AI, or ML systems processing High-impact datasets, which inherit the requirement from the data they’re processing.

• Core operational services that are used across multiple agencies, where the cumulative impact of a potential outage adds up to a High requirement.

Once you’re sure High applies, the next step is understanding what the baseline actually requires.

Core requirements of FedRAMP High

Since FedRAMP Medium generally covers SaaS used by federal agencies, it introduces the full list of control categories it expects from cloud providers. If you update from Medium to High, you won’t see a change in the categories of controls; instead, the standards intensify.

Cryptography must be validated, configurations must remain hardened, monitoring must be timely, and evidence must be complete and machine-readable. The Rev 5 set of requirements is now mandatory across all new and existing authorizations, and adds more supply-chain depth to these expectations. FedRAMP 20x is already in effect for agencies and is being gradually pushed out to cloud providers; it introduces an automation-first approach to reporting, severely restricting manual reporting and requiring evidence generated directly from build and deployment systems.

A transition from Moderate to High means the same families of controls apply, with a jump in the enforcement bar jumps. Key areas where that shift becomes visible include:

FIPS-Validated cryptography

Moderate allows some flexibility; High eliminates all options. For example, at High, 100% of your crypto dependencies must run through validated modules, while Moderate will accept some libraries running in a “FIPS-like” or “FIPS-compliant mode”. Moderate will enforce validation at the boundaries, but allow exemptions for internal communications, while High requires 100% validation end-to-end for any communication within the boundary.

System hardening and configuration standards

Both Medium and High incorporate the same Defense Information Systems Agency (DISA) produced Security Technical Implementation Guides (STIG) and Centre for Internet Security (CIS) families of system hardening standards. Moderate tolerates some drift, so minor configuration, environmental changes, or patches that deviate from the standard won’t impact compliance. At High, that flexibility is severely constrained.

Continuous monitoring and vulnerability remediation

Both levels use the same scanning cadence. High takes findings a lot more seriously; vulnerabilities automatically have tighter SLAs, and the penalties for backlogs of unaddressed vulnerabilities and recurring misses are more severe. At High, you have to keep your queue near 0, or you may lose your ATO and face mandatory corrective actions.

Transparency, auditability, and provenance

Moderate requires evidence that proves controls are in place. High raises the expectation: the evidence must be complete, consistent, and generated directly from your build and deployment pipelines. SBOMs, signatures, and provenance. These can be treated as supplemental at Medium and are required parts of systems operating proof at High that must be reproducible on demand.

The bar for High compliance is, well, high. Which begs the question, what do you get once you’re compliant?

Why FedRAMP High matters

For vendors competing for defense, national health, public safety, or multi-agency contracts, High often determines who gets invited to the table. If you can prove your systems meet the stringent requirements for shielding critical data from severe impact events, you’ll be able to serve exclusive programs where reliability, cryptography, and hardened baselines are mandatory.

Achieving the High baseline translates directly into operational and commercial advantages:

• Access to federal programs that require High-impact authorization

• Stronger standing in procurement reviews and technical evaluations

• Verifiable proof of hardened configurations and fully validated crypto

• Lower risk exposure due to stricter enforcement of controls and reduced drift

• Built-in alignment with Rev 5, 20x, and strong positioning for potential new, emerging automation expectations

Challenges in achieving FedRAMP High compliance

Moving from Medium to High is a substantial jump; what seems like 20% additional work when written down takes 80% of the total effort. This transition comes with a set of challenges that appear nearly every time someone makes the move. If tackled ad hoc and without careful investment in automation, addressing challenges becomes notoriously slow, expensive, and resource-intensive. Patchwork systems that might squeak by Medium certification can severely impact timelines and delay the issue of an Authorization to Operate (ATO) at High:

• Vulnerability backlogs: High assumes mission-level risk. Minor delays in patching can become significant and lead to lives lost or catastrophic failures, so even small delays or backlog growth can quickly cause you to fail reviews.

• Open-source dependency risk: Most open-source components ship with non-validated crypto paths or use unvetted transitive packages. These gaps immediately surface in scans at High and require remediation, since unvalidated or opaque crypto paths create uncertainty about how data is protected. That’s a kind of uncertainty that High has 0 tolerance for.

• Compliance documentation burden: High demands high volumes of evidence, which are complete, consistent, and machine-generated. Manual or fragmented documentation pipelines quickly fall out of sync with their systems, and 3PAO audits will flag these as control failures. High requires that compliance is intentional (as in, you document your intent and process in detail and then implement it). When the system behavior isn’t documented well enough, that creates a level of uncertainty about what the system is doing that is intolerable at High.

• Misaligned development and security teams: If teams aren’t aligned, evidence and system behavior will start to diverge, and teams will produce contradicting artifacts and documentation. These contradictions are immediately flagged by assessors, causing additional follow-up scrutiny and being extremely resource-intensive to resolve and address.

Best practice tips to achieve FedRAMP High

FedRAMP High is where heroic firefighting fails, and patient, methodical engineering wins. If you approach the problem as a well-defined engineering problem, you’ll move quickly to your ATO and then be able to maintain your status efficiently. That means:

• Start with secure foundations: Gold base images are a de facto industry standard. Hardened configurations and validated crypto at the base layer remove entire categories of problems.

• Automate vulnerability remediation: High-severity SLAs move too fast for manual patch cycles. Automation prevents drift and keeps your plan of action and milestones (POA&M) documentation from ballooning.

• Build audit readiness into your pipelines: Manual or ad hoc evidence generation is too slow for High. Embed SBOM, signatures, and provenance evidence generation straight into your build and CI pipelines.

• Align your teams early: Control mappings, implementations, and documentation should be co-owned by multiple teams, including at least your development and security teams. Organizational fragmentation translates directly into contradictions that your auditors will catch.

With FedRAMP 20x coming soon, if you’re expecting your evidence to come from spreadsheets, you’re already behind.

Achieve FedRAMP High with Chainguard’s secure-by-default solutions

FedRAMP High demands hardened baselines, validated cryptography, rapid remediation, and complete supply chain transparency. Chainguard packages those requirements into secure-by-default containers, libraries, and VMs that remove the heavy lifting.

Instead of patching your way into compliance, you inherit a hardened foundation that stays aligned with Rev 5, the 20x automation initiative, and ongoing Continuous Monitoring (ConMon) expectations.

Highlights:

• Zero-CVE images are rebuilt daily from source. At High, dependency stacks shift daily, and daily images eliminate drift.

• FIPS-validated and STIG-aligned components, everywhere they exist in the stack. Most common open source container bases can take months of rebuilding and re-hardening before they meet these requirements

• Attestations, Software Bill of Materials (SBOMs), and provenance are produced automatically, guaranteeing no mismatches in your artifacts for auditors to catch.

• Service-level agreement (SLA)–supported patch cycles that align to High requirements and keep your Plan of Action and Milestones (POA&M) queues clean.

• Drop-in compatibility for existing CI/CD pipelines.

If you’re preparing for FedRAMP High or planning an upgrade from Moderate, our team can help you evaluate your baselines and map out the fastest path to compliance.

Talk to an expert to see how Chainguard can simplify the work.