Most sponsors keep a single post-approval tracker: a list of studies promised to FDA, each with a target date, each treated as roughly the same kind of obligation. That framing misses a distinction the statute itself draws sharply. A postmarketing requirement (PMR) is a study FDA requires by statute or regulation; a postmarketing commitment (PMC) is a study the sponsor agrees in writing to run, with no statutory mandate behind it. Only one of them turns a missed deadline into a violation of the Federal Food, Drug, and Cosmetic Act.

What actually separates the two

The Food and Drug Administration Amendments Act of 2007 added Section 505(o)(3) to the FD&C Act, giving FDA authority to require certain postmarketing safety studies and clinical trials at approval or afterward, when the agency becomes aware of new safety information suggesting a serious risk. The statute lists three purposes a required study can serve: assessing a known serious risk, assessing a signal of a serious risk, or identifying an unexpected serious risk once available data indicate the potential for one. A study FDA requires on that basis is a PMR, and it comes with a milestone schedule the sponsor must meet and report against. A study the sponsor offers or agrees to in writing — outside that statutory trigger — is a PMC. The label each one carries is not a formality; it determines whether FDA's enforcement authority attaches to the deadline at all.

505(o)(3)
The FDAAA 2007 provision giving FDA authority to require postmarketing safety studies — the statutory basis for every PMR.
$250K
The per-violation civil monetary penalty FDA has cited for failing to comply with a PMR's timetable, with further penalties for continued noncompliance.
Sec. 506B
The separate FDAMA 1997 provision requiring annual status reports on PMCs — a different reporting track from a PMR's own milestone schedule.

Why the distinction has teeth

If a sponsor fails to conduct a PMR with due diligence, or fails to meet its reporting obligations, that failure is itself a violation of the FD&C Act or its implementing regulations and is subject to enforcement action — FDA's own guidance describes Warning Letters and civil monetary penalties as the available tools, with penalties historically running up to $250,000 per violation, additional penalties for a violation that continues uncorrected, and a product that can be deemed misbranded on top of the monetary exposure. None of that attaches to a missed PMC. A PMC's enforcement mechanism is narrower and procedural: Section 506B requires the sponsor to report the commitment's status annually, including the reasons for any delay, but failing to complete the study on schedule is not, on its own, an FDCA violation. Both obligations show up on FDA's public PMR/PMC reporting; only one of them exposes the sponsor to the statute's penalty provisions if the date slips.

  • Legal basis. A PMR traces to Section 505(o)(3) (or another specific statutory/regulatory requirement); a PMC has no such mandate behind it.
  • Consequence of a miss. A PMR miss is itself a potential FDCA violation — Warning Letter, civil monetary penalties, misbranding exposure. A PMC miss triggers a required explanation in the next annual report, not an enforcement action by itself.
  • Reporting track. PMRs report against the 505(o) milestone schedule set at the time FDA imposes the requirement; PMCs report annually under Section 506B and 21 CFR 314.81(b)(2)(vii).
  • Common PMR trigger teams underestimate. A confirmatory trial tied to accelerated approval is, in practice, a PMR: Section 506(c) makes it a condition of approval FDA may require, and recent amendments let FDA require the trial be underway before approval at all.
Every item on a post-approval tracker looks like the same kind of promise. Only the PMRs are promises the statute will enforce if the date slips. Why sorting the tracker matters

Where this shows up in practice

The confusion is understandable: both categories appear side by side in FDA's own public postmarketing reports, both get assigned at or after approval, and both are frequently negotiated in the same set of conversations with a review division. A product approved under an accelerated pathway is the clearest case where getting the label wrong has consequences — its confirmatory trial is a condition of that approval, not a goodwill gesture, and treating it administratively like a PMC understates the exposure if the trial slips or FDA judges it is not being pursued with due diligence. A REMS modification raises a parallel question in a different obligation category: knowing which commitments in a post-approval package carry statutory teeth and which do not changes how a regulatory team prioritizes, staffs, and escalates when a milestone is at risk.

Sort the tracker before the next deadline
  1. Pull the approval letter and schedule. Confirm which studies FDA designated as PMRs with a 505(o) milestone date, separate from any PMC.
  2. Flag the enforcement-bearing studies. Treat every PMR date as a hard deadline with FDCA exposure attached.
  3. Route the two reporting tracks separately. PMRs against 505(o) milestones; PMCs annually under Section 506B / 21 CFR 314.81(b)(2)(vii).
  4. Re-check accelerated-approval confirmatory trials. Confirm they are tracked as PMRs under Section 506(c), not logged as discretionary commitments.

Frequently asked questions

What is the difference between an FDA postmarketing requirement and a postmarketing commitment?

A PMR is a study FDA requires under statute or regulation — generally FD&C Act Section 505(o)(3) — and failing to conduct it with due diligence is itself a statutory violation subject to enforcement. A PMC is a study the sponsor agrees in writing to conduct; it is not required by statute or regulation, so missing one is not itself a violation.

What happens if a sponsor misses a PMR deadline?

FDA can issue a Warning Letter and assess civil monetary penalties — historically up to $250,000 per violation, with further penalties for continued noncompliance and an aggregate cap per proceeding — and the product can be deemed misbranded. A PMC carries no equivalent statutory penalty for a missed milestone.

Are confirmatory trials under accelerated approval PMRs or PMCs?

In practice, PMRs. Since the 2012 FDASIA amendments, FD&C Act Section 506(c) makes a confirmatory trial a condition of accelerated approval FDA may require — and the 2023 omnibus law let FDA require the trial be underway before approval — which FDA tracks as a required postmarketing study, not a voluntary commitment.

Sources & further reading

  1. FDA. Guidance for Industry: Postmarketing Studies and Clinical Trials — Implementation of Section 505(o)(3) of the Federal Food, Drug, and Cosmetic Act. fda.gov
  2. 21 U.S.C. 355(o) — New drug, antibiotic, and biological drug product authorities concerning safety. govinfo.gov

This article is provided for general informational purposes and reflects the regulatory landscape as of October 2026. It is not legal or regulatory advice. Confirm current PMR/PMC classification and penalty amounts, which are subject to periodic inflation adjustment, directly with FDA or qualified counsel before acting.