All terms
Medical Device Data System
Hardware or software intended to transfer, store, convert format, or display medical device data, generally not actively regulated by FDA after 2017 Cures Act amendments.
Reviewed by Christian Espinosa, Founder, Blue Goat CyberLast reviewed June 20, 2026
Definition
A Medical Device Data System (MDDS) is hardware or software intended to transfer, store, convert format, or display medical device data without controlling the functions or parameters of any connected medical device. The 21st Century Cures Act (2016) amended Section 520(o) of the FD&C Act to exclude most MDDS functions from the definition of a medical device, meaning FDA does not actively regulate software whose sole purpose is to perform these functions. However, software that interprets data, generates alarms based on data, or controls another device is not MDDS and remains a medical device. What the regulation says
FD&C Act §520(o) as amended by the 21st Century Cures Act §3060. FDA's 'Clinical Decision Support Software' guidance (2022, final) and 'Changes to Existing Medical Software Policies Resulting from Section 3060' guidance clarify what remains regulated after Cures.What this means in practice
MDDS classification has significant strategic implications for software vendors. A platform that purely moves and displays data from connected devices may not require FDA submission; the moment it adds analytics that interpret or trigger clinical action, it becomes a regulated SaMD. The boundary is enforced narrowly by FDA, even simple thresholding or trending logic typically crosses the line. Manufacturers must document MDDS-vs-SaMD classification logic and version-control any feature changes that could move a product across the boundary. Common pitfalls
- •Claiming MDDS for software that interprets data, analytics, alarms, scoring, and clinical recommendations are not MDDS.
- •Letting MDDS scope creep without re-evaluation, features added over time can shift the product across the regulatory boundary.
- •Confusing MDDS with Clinical Decision Support (CDS), they are different exclusions with different criteria under §520(o).
Primary references
3 sourcesLink health: 2 verified 1 bot-blocked· last checked 2026-06-20
FDA·1Cornell Law·1IMDRF·1
- 1Changes to Software Policies (Section 3060) GuidanceBot-blockedFDAfda.gov
- 2FD&C Act §520(o)VerifiedCornell Lawlaw.cornell.edu
- 3IMDRF - Software as a Medical DeviceVerifiedIMDRFimdrf.org
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