What is ClinicalTrials.gov?

ClinicalTrials.gov is a resource that provides access to information on clinical trials studying a wide range of diseases, conditions and interventions. Studies listed in the database are conducted in all 50 States and worldwide. Each ClinicalTrials.gov record includes summary information about studies.

EQUIP TIP: The clinicaltrials.gov record may be released for PRS review AFTER IRB submission.

Registration may be required if one (or more) of the following is true:

  1. Your study is funded by the National Institutes of Health (NIHAND meets the NIH definition of a clinical trial  [learn more...]

  2. Your study involves drugs, devices, or biologics that are regulated by the Food and Drug Administration (FDA) and meets the definition of an Applicable Clinical Trial (ACT) [learn more...]

  3. The study meets the International Committee of Medical Journal Editors (ICMJE) definition of a clinical trial AND there is a plan to publish the results in an ICMJE journal [learn more...]

  4. If your clinical trial will bill routine costs to Medicare, the study must be registered on ClinicalTrials.gov [learn more...]

  5. If your clinical trial receives funding from Department of Defense, Patient-Centered Outcomes Research Institute (PCORI), National Cancer Institute (NCI), Veterans Affairs (VA) [learn more...]


START HERE - How To Register and Update Your Study

NEW! - ClinicalTrials.gov OFFICE HOURS Fridays 11am-12pm

Checklist To Address Common Errors

Important Definitions of Required Elements

OHRP Guidance - Posting the Consent Form

Registration Requirements

NIH funded clinical trials are required to be registered:

  • If your study is NIH funded and meets the NIH definition of a clinical trial, then clinicaltrials.gov registration is required.
  • For NIH funded research, use the following four questions to determine the difference between a clinical study and a clinical trial:
    • Does the study involve human participants?
    • Are the participants prospectively assigned to one or more interventions?
    • Is the study designed to evaluate the effect of the intervention on the participants?
    • Is the effect being evaluated a health-related biomedical or behavioral outcome?
  • If the answers to ALL 4 questions are “yes”, your study meets the NIH definition of a clinical trial.
  •  Clinical trials subject to the regulation are generally called "applicable clinical trials."
  • Applicable clinical trials are required to be registered in ClinicalTrials.gov not later than 21 calendar days after the enrollment of the first participant. 

**Resource: What NIH Researchers and Recipients Should Know about ClinicalTrials.gov Podcast

NIH Definition of an “INTERVENTION”:

An "intervention" is defined as a manipulation of the subject or subject’s environment for the purpose of modifying one or more health-related biomedical or behavioral processes and/or endpoints.

Examples include:

  • drugs/small molecules/compounds;
  • biologics; devices;
  • procedures (e.g., surgical techniques);
  • delivery systems (e.g., telemedicine, face-to-face interviews);
  • strategies to change health-related behavior (e.g., diet, cognitive therapy, exercise training, development of new habits);
  • treatment strategies; prevention strategies; and diagnostic strategies.

This Includes

- studies with healthy participants

Phase 1 trials of FDA-regulated drugs and biological products

Small feasibility studies of FDA regulated device products

– studies with no comparison group (placebo or control)

– studies designed to assess the pharmacokinetics / safety of an investigational drug

– Studies where only one aim or sub-aim meets the clinical trial definition.

Wide Range of NIH Interventions include: mechanic, exploratory/development, piot/feasibility, other interventional, behavioral, basic experimental
Basic experimental studies involving humans (BESH)

Basic experimental studies involving humans:

These meet both the definition of basic research and the NIH definition of a clinical trial.

  • NIH published clinical trial case studies with examples of BESH (example - cases 16, 21, 23 and 31b).
  • Example: healthy volunteers randomized to different durations of sleep deprivation where the dependent variable is stress hormone levels.

NIH Policy on Dissemination of NIH-Funded Clinical Trial Information:

  • This policy applies to all NIH-funded clinical trials regardless of study phase, type of intervention, or whether they are subject to the regulation.
  • As such, the policy encompasses all NIH-funded clinical trials, including applicable clinical trials subject to the regulation.  All NIH-funded clinical trials will be expected to register and submit results information to ClinicalTrials.gov.
    • In the regulation, results information includes participant flow, demographic and baseline characteristics, outcomes and statistical analyses, adverse events, the protocol and statistical analysis plan, and administrative information.
    • In addition, informed consent documents for clinical trials are to include a specific statement relating to posting of clinical trial information at ClinicalTrials.gov.

Clinical Trial Indicator:

  • The NIH Award Notice includes a "Clinical Trial Indicator" in Section IV which specifies whether the award supports any NIH defined clinical trials.
  • If the Clinical Trial Indicator specifies "No" then your study does NOT meet the NIH definition of a clinical trial and therefore does not need to be registered on Clincaltrials.gov.
  • If the Clinical Trial Indicator specifies "Yes" then your study meets the NIH definition of a clinical trial and must be registered on Clincaltrials.gov.


The Food and Drug Administration Amendments Act of 2007 (FDAAA) established legal requirements for sponsors and designated principal investigators (i.e., responsible parties) to report specified clinical trial information for certain ACT’s to ClinicalTrials.gov.

The requirements are designed to

  • provide potential participants with information about trials of interest,
  • reduce publication bias,
  • help institutional review boards (IRBs) determine the appropriateness of a research study,
  • and promote more efficient allocation of research funds.
(Decorative) FDA Stamp of approval

Registration is also required if your study meets the DHHS definition of an Applicable Clinical Trial (ACT) These include:

  • Controlled clinical investigations (other than phase 1 investigations) of any U.S. Food and Drug Administration (FDA) -regulated drug or biological product for any disease or condition
  • It also includes certain studies of FDA-regulated medical devices, and FDA-required pediatric post market surveillances of a device product

Researchers can use the following tools to determine if their trial meets the DHHS definition of an ACT:

ACT – important definitions:

Is the study interventional (a clinical trial)?

  • Participants are prospectively assigned to an intervention(s) to evaluate the effect of the intervention(s) on biomedical or other health-related outcomes. [Source: 42 CFR 11.10(a); 81 FR 65140-41]

Does the study evaluate at least one U.S. FDA-regulated drug, biological, or device product?

FDA-regulated Device Product means:

  • A device product  subject to (1) a finding of substantial equivalence under section 510(k) of the FD&C Act, (2) under section 515 - requiring a premarket approval application (PMA) for the device product, or (3) a marketing application for a Humanitarian Use Device (HUD) - a Humanitarian Device Exemption under section 520(m) of the FD&C Act.
  • Device products that are considered to be subject to section 510(k), 515, or 520(m) of the FD&C Act include significant risk devices for which approval of an IDE is required, non-significant risk devices that subject to abbreviated IDE requirements (21 CFR 812.2(b)), or device products that are exempt from the submission requirements of 21 CFR part 812.
  • It DOES NOT include device feasibility, Phase 0 or Phase 1 trials.


FDA-regulated Drug Product  means:

  • A drug that is the subject of an approved NDA (new drug application) or BLA (biologic license application) or that would require an approved NDA or BLA to be legally marketed in the United States.
  • A clinical trial including an intervention with a “dietary supplement” could  be an ACT.
  • It DOES NOT include Phase 0 or Phase 1 drug / biologic trials. For determining whether a drug / biological is the variable of interest, see page 8 of the ACT checklist

Sponsor-Investigators submitting an IND, NDA, BLA, or 510k etc. application to the FDA:

  • The FDA recommends that Form FDA 3674 accompany the submission.
  • Per instructions on Form FDA 3674, Sponsors must "provide the NCT Number obtained from www.ClinicalTrials.gov for each applicable clinical trial for which the sponsor/ applicant/submitter is the “responsible party” and for which data is included, relied upon, or otherwise referred to, in the application/submission which the certification accompanies."
  • Box 10 may be left blank if the submitter has checked Box 9.C but, at the time the certification is completed, the submitter has not yet received any NCT number(s) for the applicable clinical trial(s) for which data is included, relied upon, or otherwise referred to in the IND application. There is no requirement to register the study on clinicaltirals.gov at this time! 
  •  The only expectation for registration per FDA is outlined in 42 CFR 11.24(a):
    • General. Except as provided in paragraph (b) of this section, the responsible party for an applicable clinical trial for which submission of clinical trial registration information is required must submit the clinical trial registration information specified in section 402(j)(2)(A)(ii) of the Public Health Service Act (42 U.S.C. 282(j)(2)(A)(ii)) or § 11.28(a), as applicable, not later than December 26, 2007, or 21 calendar days after the first human subject is enrolled, whichever date is later.
  • Please note that an updated Form FDA 3674 providing the applicable clinical trial’s NCT number is not required to be submitted to the IND after the trial is registered on ClinicalTrials.gov. However, the trial’s NCT number may need to be included in a Form FDA 3674 that accompanies a future application or submission to FDA (e.g., the submission of a new protocol to the IND).

Registration Requirements per International Committee of Medical Journal Editors (ICMJE):

Image of multiple medical journals
  • In 2005, the ICMJE defined trials that must be registered in order to be considered for publication in journals that adhere to ICMJE standards.
  • The ICMJE requires registration of clinical trials in a public trials registry at or before enrollment of the first participant to be considered for publication.
  • Which journals are members of the ICMJE?
  • Many journals (not limited to medical journals) have adopted the registration policy.** Editors requesting inclusion of their journal on the ICMJE website list of publications that follow ICMJE guidance listing implies enforcement by the journal of ICMJE’s trial registration policy.
Dictionary image/icon

The ICMJE definition of clinical trial: "any research study that prospectively assigns human participants or groups of humans to one or more health-related interventions to evaluate the effects on health outcomes.

  • With or without concurrent comparison or control groups,
  • Health-related interventions are those used to modify a biomedical or health-related outcome; examples include drugs, surgical procedures, devices, behavioral treatments, educational programs, dietary interventions, quality improvement interventions, and process-of-care changes.
  • Health outcomes are any biomedical or health-related measures obtained in patients or participants, including pharmacokinetic measures and adverse events.
  • …encourages registration of research with non-trial designs (e.g., observational studies)
  • …journals will consider trials beginning on or after July 1, 2005 only if registration occurred before the first patient was enrolled ("prospective registration").
  • …does not define the timing of first participant enrollment, but best practice dictates registration by the time of first participant consent.
  • An acceptable registry must include the minimum 24-item trial registration data set at the time of registration.

**Those who are uncertain whether their trial meets the expanded ICMJE definition should err on the side of registration if they wish to seek publication in an ICMJE journal**

  • If your study will bill costs of routine standard of care to Medicare or any other insurer, the study must be registered on ClinicalTrials.gov to obtain the NCT#.
  • Claims for routine costs of Qualifying Clinical Trials (QCT) as well as services used to diagnose / treat complications arising from participation in all clinical trials covered by Medicare will require health care providers and suppliers to report a ClinicalTrials.gov Identifier (NCT Number).
  • The Centers for Medicare and Medicaid Service (CMS) issued a Clinical Trial Policy (CTP) - a National Coverage Determination (NCD) that allows payment of routine items/services, and payment of the investigational item/service if it is covered outside the trial, in clinical trials that qualify for coverage.

If you have a clinical trial that includes a drug that's available via expanded access:

Under FDA regulations (21 CFR 312.300), expanded access allows for the use of unapproved drugs and biologics outside of a clinical trial for patients with serious diseases or conditions when there is no satisfactory alternative therapy to treat the patient’s disease or condition. This is sometimes referred to as compassionate use or treatment use.

For an applicable drug clinical trial of an unapproved drug product the Public Health Service Act requires the submission of a separate expanded access record containing details about how to obtain access to the investigational product.

The final rule does not consider any expanded access use (i.e., access under treatment INDs or treatment protocols, which provide widespread access, access for intermediate-sized patient populations, or access for individual patients) to be an applicable clinical trial.

Note: Only a responsible party who is both the manufacturer of an investigational drug product or biological product and the sponsor of the trial can submit registration information for expanded access programs to ct.gov.

A responsible party who is not BOTH the manufacturer of the investigational drug product or biological product and the sponsor of the trial is not required to submit information for the Availability of Expanded Access data element (i.e., should select the response "unknown" for that data element). (81 FR 65052)

For example, a physician who submits an individual patient expanded access Investigational New Drug Application (IND), including for emergency use, as specified in 21 CFR 312.310, to the U.S. Food and Drug Administration generally would not be required to submit expanded access information to ClinicalTrials.gov.

Summary of requirements:

EntityRegistrationResults ReportingPenalties
Health and Human Services
Within 21 days of enrollmentWithin 365 days of primary completion date for ACTs
  • $13,237/study/day
  • Criminal proceedings
  • Loss of grant funding
National Istitutes of Health
Within 21 days of enrollmentWithin 365 days of primary completion date
for clinical trials receiving NIH funding
  • Loss of grant funding (to include the institution)
National Cancer Institute
Within 21 days of enrollmentWithin 365 days of primary completion date of NCI-supported clinical trials (in a peer-reviewed journal and/or ClinicalTrials.gov)
  • Loss of grant funding
Veterans Health Administration
Prior to release of funding. Prior to enrollmentWithin 365 days of primary completion date
  • Loss of grant funding
Centers for Medicare & Medicaid Services
All qualifying clinical trialsStudy-specific
  • Coverage denial
  • Costs and fraud investigations
Patient-Centered Outcomes Research Institute
All Clinical studies (including observational)Expected of all PCORI
Clinical studies – 500 word abstract published on PCORI website
  • Loss of grant funding
International Committee of Medical Journal Editors
Prior to enrollment
  • Ineligibility to publish
Department of Defense
Prior to enrollment.
Prior to release of funding.
  • $13,237/study/day
  • Withholding or recovery of award funds

Adapted from: Clinicaltrials.gov enforcement: an update. Anthony Keyes. January 18, 2022

Registration & Submission

In 2015: 19,170 clinical trials were registered. 7,400 were applicable clinical trials, the remainder 11,770 trials, can be considered voluntary or to not fall under the rule. Of these, 526 were NIH funded. This leaves an estimated 11,244 trials that do not fall under either the rule or the NIH policy!

DHHS expects that these voluntary registrations will:

  • submit the same clinical trial registration information as applicable clinical trials.
  • expects that required elements of the record are updated as frequently as information for applicable clinical trials.
  • Estimated annual burden of 269,856 hours (almost 90,000 hours initial registration, rest from updates)

Voluntary registration places a burden on the responsible party  to comply with all registration and update requirements. Any ongoing non-compliance with these requirements on the part of the responsible party.

Source: Final Rule 42 CFR Part 11: https://www.govinfo.gov/content/pkg/FR-2016-09-21/pdf/2016-22129.pdf

  • The “Responsible Party” refers to the entity or individual who is responsible for registering a trial on ClinicalTrials.gov.
  • The Responsible Party is responsible for the initial release of the record, all future updates and ensuring the trial registration stays accurate and up-to-date.
  • For studies registered by UCI, the PI serves as the responsible party if they meet all the following criteria:
    1. They are responsible for conducting the clinical trial.
    2. They have access to and control over the data
    3. They have the right to publish the results of the trial
    4. They can meet all the requirements for the submission of clinical trial information.

  1. A ClinicalTrials.gov staff member will review the study record after it is submitted and before it is published on ClinicalTrials.gov.
  2. The review process may take up to a few days. Ensuring that the record is consistent with the ClinicalTrials.gov Protocol Review Criteria (PDF) before releasing it will expedite publication on the site.
  3. After it is accepted by review staff for publication, the record, including its NCT Number, will be available on ClinicalTrials.gov within 2–5 business days.
  • Record Verification Date: Clinical trial registration information must be updated not less than once every 12 months.
  • The following elements must be updated 30 days after a change:
    • Human Subjects Protection Review Board Status
    • Overall Recruitment Status1.
    • Primary Completion Date
    • Study Completion Date
    • Responsible Party Contact Information or contact information
    • Intervention Name(s)
    • Individual Site Status

Results Reporting:

  • The Food and Drug Administration Amendments Act (FDAAA), National Institutes of Health (NIH) require the publication of results for certain studies on ClinicalTrials.gov (Ct.gov).
  • The ICMJE Policy recommends results publication but it is not required.
  • After a clinical trial has been registered on ClinicalTrials.gov and the study is completed, the Responsible Party must publish the results on ClinicalTrials.gov.
  • Submission of results information is required no later than 12 months after the Primary Completion Date (the last subject last visit) of the clinical trial, which is defined as the date of final data collection for the primary outcome measure.

1 - If Overall Recruitment Status is changed to "suspended," "terminated," or "withdrawn," the Why Study Stopped data element must be submitted at the time the update is made.

If needed submit an Amendment for the following

  • For studies that meet the criteria for clinical trials per NIH Definition and Applicable Clinical Trials, ensure the ClinicalTrials.gov statement is included in the Consent Form / Study Information Sheet
  • Under “Type of Research” – “yes” to Does this research meet the definition of a clinical trial that requires adherence to Clinicaltrials.gov?
  • Once obtained, NCT# is added to this section
  • Recruitment section reflects ClinicalTrials.gov as a recruitment method.

Effective January 21, 2019. Important considerations regarding the uploading of the informed consent form:

Applies to clinical trials conducted or supported by a Federal department or agency using the Common Rule (e.g., NIH, DOD, DVA)

Should be uploaded no later than 60 days after the last study visit by any subject, as required by the protocol.

The consent form must have been used in enrolling participants.

Must be uploaded to either ClinicalTrials.gov or a docket folder on Regulations.gov

Why Do I Need to Register My Trial and Submit Results to ClinicalTrials.gov?