[Home](/)/[Resources](/resources)/US Software as a Medical Device (SaMD) USMedical devicesRegulation guide # US Software as a Medical Device (SaMD) Software that diagnoses, treats, monitors, or otherwise drives a medical decision can be regulated by the FDA as a medical device in its own right — independent of any hardware it runs on. Getting the classification and pathway decision wrong early is one of the most expensive mistakes a digital health company can make. Copy Link[Share on WhatsApp](https://wa.me/?text=https%3A%2F%2Fkrono-labs.com%2Fguides%2Fus-samd-software-medical-device) At a glance Regulator FDA, Center for Devices and Radiological Health Key question Does the software meet the device definition? Common pathways 510(k), De Novo, PMA Risk framework IMDRF-aligned SaMD risk categorization Related exclusion Certain Clinical Decision Support software (21st Century Cures Act) ## When software becomes a medical device ### The statutory device definition Software intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease, or intended to affect the structure or function of the body, meets the FD&C Act’s device definition regardless of whether it runs on dedicated hardware, a phone, or in the cloud. ### The Clinical Decision Support carve-out The 21st Century Cures Act excludes certain lower-risk Clinical Decision Support (CDS) software from device regulation — specifically software that displays, analyzes, or prints information without acquiring, processing, or analyzing a medical image or signal, and where a clinician can independently review the basis for the recommendation. ### Wellness vs. medical claims General wellness software making claims unrelated to a specific disease or condition typically falls outside FDA device jurisdiction under the agency’s general wellness policy — but adding a disease-specific claim can pull the same product back into scope. ## Classification and pathway ### Risk-based classification SaMD is classified into Class I, II, or III based on the risk the software’s output poses if the information is wrong or the software fails, following the same three-class structure used for hardware medical devices. ### 510(k) premarket notification Most moderate-risk SaMD (Class II) reaches market by demonstrating substantial equivalence to a legally marketed predicate device through the 510(k) pathway — the most common route for SaMD with an existing predicate. ### De Novo classification Novel SaMD with no suitable predicate but low-to-moderate risk can use the De Novo pathway to establish a new device classification, which then becomes available as a predicate for later similar products. ### PMA for high-risk software SaMD with the highest risk profile — where an incorrect output could directly cause serious harm without independent clinician verification — may require a full Premarket Approval (PMA) application with clinical evidence. ## Building a SaMD regulatory strategy 01 Determine whether your software meets the device definition, and separately check whether it fits the Clinical Decision Support exclusion or general wellness policy before assuming device status. 02 Identify potential predicate devices for a 510(k) pathway, or confirm no predicate exists to justify a De Novo submission. 03 Scope your clinical evidence needs early — algorithm validation, analytical performance, and, where relevant, clinical performance data — since evidence expectations differ sharply by risk class. 04 Build your quality system to FDA Quality System Regulation expectations from the start; retrofitting design controls onto software built without them is expensive. 05 Plan for software-specific post-market obligations, including how you will manage and document updates to an already-cleared or approved algorithm. ## Frequently asked questions ### Is all health-related software regulated by the FDA? No. Software making general wellness claims unrelated to a specific disease, and certain Clinical Decision Support software meeting the 21st Century Cures Act criteria, typically fall outside FDA device jurisdiction. The determining factor is the specific intended use and claims, not simply that the software touches health data. ### Does SaMD need its own 510(k) even if it runs on FDA-cleared hardware? Generally yes — SaMD is evaluated on its own intended use and risk profile. Running on cleared hardware does not automatically extend that clearance to the software; the software itself needs its own appropriate pathway if it independently meets the device definition. ### What is the difference between 510(k) and De Novo for SaMD? 510(k) requires demonstrating substantial equivalence to an existing predicate device already on the market. De Novo is used when no suitable predicate exists but the product’s risk is low-to-moderate — it creates a new classification rather than relying on an existing one. ### How does FDA treat AI/ML-based SaMD differently? Software that continues to learn or update after deployment raises additional questions about how changes to the algorithm are controlled and disclosed. FDA has published guidance on predetermined change control plans specifically to let manufacturers pre-specify how an algorithm may adapt without triggering a new submission for every update — a mechanism worth evaluating early for adaptive algorithms. **Disclaimer:** This page is an educational resource only and does not constitute legal or regulatory advice. FDA guidance on software as a medical device, including AI/ML-specific policy, continues to evolve — consult current FDA guidance documents and qualified regulatory counsel before finalizing a submission strategy. 🇺🇸 US roadmap for medical devices Every standard, document, and test that applies — free, no account required. See your free roadmap[ Want an expert to take medical devices through 🇺🇸 US compliance for you? One consultant from Krono's compliance team takes your product from requirements to legal sale, with a fixed quote before any work starts. See compliance services](/services) Learn this properly In-depth course that teaches the full process, not just this one answer. [Start the course — $199](/courses/17-fda-medical-device-registration-510k-hardware-startups)[Prefer to read? Get the book — $24.99](/books/17-fda-medical-device-registration-510k-hardware-startups) Related guides * [US 510(k) Premarket NotificationComplete guide to US 510(k) premarket notification.](/guides/us-510k-premarket-notification) * [US De Novo ClassificationComplete guide to US De Novo classification.](/guides/us-de-novo-classification) * [UK Software as a Medical DeviceComplete guide to Software as a Medical Device (SaMD) in the UK: MHRA classification framework, when software qualifies as a me…](/guides/uk-software-medical-device) * [US Medical Devices ClassificationComplete guide to US medical devices classification.](/guides/us-medical-devices-classification)