Postmarket Surveillance for Medical Devices: What It Is Designed to Learn

By the Connected Diagnostics Evidence Team

A Device Gets Cleared. What Does Postmarket Surveillance Do Next?

Postmarket surveillance is the FDA’s ongoing monitoring of a medical device after it’s already on the market, separate from the review that happened before the device was cleared or approved. Say a connected health device — a digital otoscope, a home monitoring tool, a diagnostic app tied to a sensor — passes that initial FDA review and reaches the market. Months later, a news story mentions the FDA is “monitoring” the device, or a report shows up in a federal database. That doesn’t automatically mean something went wrong — it usually means the device has entered this next phase of oversight.

What Are the Two Checkpoints in Device Oversight?

It helps to separate two stages that people sometimes confuse:

• Premarket review happens before a device reaches the market. The FDA evaluates the evidence a manufacturer submits about safety and effectiveness.
• Postmarket surveillance happens after a device is already in use. It is ongoing monitoring, not a one-time approval decision.

Postmarket surveillance exists because real-world use over time can reveal patterns that premarket testing — done on a smaller scale, for a shorter period — cannot fully predict.

Where the Authority for Postmarket Surveillance Comes From

Section 522 of the Federal Food, Drug, and Cosmetic Act gives the FDA authority to require a manufacturer to conduct postmarket surveillance of certain class II or class III devices. The FDA can order this when a device is cleared or approved, or at any time afterward, when it meets specific criteria—for example, if the device’s failure could reasonably cause a serious health consequence or if it is implanted for more than a year.

When the FDA orders this kind of surveillance, it is described as the active, systematic, and scientifically valid collection, analysis, and interpretation of data about a device already on the market. The goal is to answer specific public health questions about the device — not to re-run the original approval decision.

What Is Postmarket Surveillance Designed to Learn?

Postmarket monitoring draws on more than one information channel. Two of the main ones are:

• 522-ordered surveillance studies. Formal, FDA-approved study protocols a manufacturer must follow when ordered. They’re designed to answer a defined question — for instance, how a device performs over a longer time period or in a specific population.
• Medical Device Reports (MDRs). A separate reporting system. Manufacturers, importers, and device user facilities such as hospitals must report when they learn a device may have caused or contributed to a death or serious injury, or malfunctioned in a way that could cause one if it happened again. Health professionals, patients, and caregivers can also submit reports voluntarily.

Together, these tools help the FDA watch for safety or performance questions that only become visible once many people use a device in many settings over time.

What Can Postmarket Surveillance Data Suggest — and What Can’t It Tell You?

This is the part that’s easy to misread, so it’s worth stating plainly. The FDA is explicit that a report does not mean a device caused harm.

A single Medical Device Report is one person’s account of a possible problem — it has not been verified, and filing one is not evidence that the device was at fault. Even a report that mentions a death is not automatically classified that way unless the reporter believes the device was or may have been a contributing factor.

The FDA also describes MDR data as a passive surveillance system with real limits: events can be under-reported, reports can contain inaccuracies, there’s no built-in verification that the device actually caused what was reported, and there’s often no reliable count of how many people used the device safely without incident. Because of this, MDRs are treated as one of several postmarket data sources the FDA relies on—not a standalone verdict on any individual device.

In short: postmarket surveillance is built to spot patterns worth investigating across a population. It is not a safety score for any one device, and it is not a diagnosis or risk assessment for any one person’s situation.

How Do You Read a Postmarket Surveillance Signal? A Simple Decision Path

If you come across a mention of postmarket surveillance, a 522 study, or an MDR entry connected to a device, use this sequence:

1. If the item is a 522-ordered study with a defined research question, treat it as formal, structured monitoring—not a red flag by itself.
2. If it’s a single MDR report, then treat it as one unverified data point, not a confirmed finding.
3. If a study result or a cluster of reports leads to further FDA review or a label update, then that follow-up action — not the original report — is the more meaningful signal.
4. If the question is about your own device or your own health, a population-level surveillance signal isn’t the resource for that—that’s a question for a healthcare professional.

How Do You Report a Device Problem, or Check on One?

Patients, caregivers, and consumers can voluntarily report a suspected device problem to the FDA through MedWatch, the FDA’s Safety Information and Adverse Event Reporting Program. This is separate from the mandatory reporting that manufacturers, importers, and device user facilities must follow. For background on how to evaluate a device claim before you get to this point, Start Here lays out the reader paths this publication covers.

If you believe you’re facing a medical emergency, postmarket surveillance data is not the resource for that moment — contact local emergency services or your healthcare provider directly.

Frequently Asked Questions

Does a Medical Device Report Mean the Device Caused Harm?

No. The FDA states that submitting an MDR is not evidence that a device caused or contributed to an adverse outcome. The FDA reviews reports, but a report alone is an unverified account, not a confirmed finding.

What’s the Difference Between an MDR and a 522 Study?

An MDR is an individual report of a possible device problem, submitted by manufacturers, importers, device user facilities, or voluntarily by patients and clinicians. A 522 study is a formal, FDA-approved research protocol a manufacturer is ordered to follow to answer a specific public health question about a device.

Can Patients Report a Device Problem Themselves?

Yes. Patients, healthcare professionals, and consumers can voluntarily submit a report through MedWatch, the FDA’s Safety Information and Adverse Event Reporting Program, separate from the mandatory reporting manufacturers and facilities must do.

Sources and Limits of This Guide

This guide draws directly on two FDA sources: the FDA’s guidance document on Postmarket Surveillance Under Section 522 of the Federal Food, Drug, and Cosmetic Act, and the FDA’s Medical Device Reporting (MDR) page. It does not cover every postmarket tool the FDA uses, and it does not evaluate any specific product, brand, or device model. For more on how sources like these are selected and verified for this site’s guides, see How We Research.

This article provides general education on how FDA postmarket surveillance works. It is not medical advice, and it is not an assessment of any individual device’s safety. It does not diagnose, recommend, or evaluate any product. For questions about a specific device or a health concern, talk to a qualified healthcare professional or contact the FDA directly.

Connected Diagnostics Evidence is an independent editorial publication at CellScope.com. It is not affiliated with the former CellScope company and does not own, operate, support, or continue its products, research, records, or team.

By Connected Diagnostics Evidence Editorial Team. Last updated September 9, 2026.