FISMA and FedRAMP both use NIST SP 800-53 as their control catalog, but they apply to different things and lead to different authorizations. FISMA governs federal information systems; FedRAMP standardizes the authorization of cloud services sold to the federal government. Mixing them up is one of the most common mistakes in federal compliance.
What FISMA is
FISMA — the Federal Information Security Modernization Act — governs federal information systems and the contractors who operate them on an agency's behalf. Every federal system must be assessed and authorized through the NIST Risk Management Framework, with controls drawn from NIST SP 800-53.
The result is an agency-issued Authorization to Operate (ATO). The agency owns the risk decision, and the authorization applies to that agency's use of that system.
What FedRAMP is
FedRAMP — the Federal Risk and Authorization Management Program — is specifically for cloud service providers (CSPs) that want to sell their cloud offering to the federal government. It standardizes the assessment so a CSP can be authorized once and reused across many agencies.
FedRAMP authorizations come either through the Joint Authorization Board (JAB P-ATO) or through a sponsoring agency (Agency ATO). Either way, the authorization travels with the cloud service, not with a single agency's use of it.
Where they overlap and where they don't
Both use NIST SP 800-53 controls, tailored to impact level (low, moderate, or high). Both produce an SSPP, SAR, and POA&M. Both require continuous monitoring after authorization.
The difference is scope. FISMA authorizes a system for an agency. FedRAMP authorizes a cloud service for reuse across the government. The artifacts look similar; the audience and reuse model do not.
When you need both
If you are a cloud provider selling to federal agencies, you need FedRAMP for your cloud service, and the agency consuming it will still go through their own FISMA/RMF process for the system they build on top of it. The cloud platform is FedRAMP-authorized; the agency's use of it is FISMA-authorized.
They stack. Knowing which one you need — and which one your customer needs — is the first conversation worth having before scoping any compliance work.
Related service
FISMA compliance & authorization