Single IRB Guide

This guidance addresses how and when COMIRB will serve as a single IRB (sIRB) for multicenter research. Links to related forms and background information are provided below. If you want to rely on an external IRB, contact the External IRB team.

Step One

Ask us if COMIRB can serve as sIRB for your research. Send a copy of the protocol or funding proposal and a list of the potential sites to:

We may schedule a meeting with the PI and study team to go over their additional responsibilities and the COMIRB review process. We may also discuss strategies to involve institutions in the research without formally "engaging" them in human subjects research.

 Basic requirements for COMIRB to serve as sIRB

  • The research must require full board or expedited IRB approval.
  • The research must involve the University of Colorado Denver | Anschutz Medical Campus or one of our affiliates.
  • Each relying site must have an active Federalwide Assurance (FWA).
  • The PI on the COMIRB application must assume additional responsibilities for IRB-related oversight of relying sites. See COMIRB Lead IRB PI Responsibilities form.
  • The relying site(s) must be in the United States.
  • The relying site(s) must agree to rely on COMIRB.
  • COMIRB will require at least annual continuing review if investigators at relying sites are interacting with subjects.

 COMIRB will not serve as sIRB

  • For unfunded clinical investigations,
  • For industry-funded clinical investigations,
  • For international sites,
  • For VA sites outside VA ECHCS,
  • For exempt research,
  • For non-human subjects research determinations, including quality improvement, quality assurance, and program evaluations,
  • For participating sites which are not engaged in human subjects research,
  • For institutions that do not have an FWA,
  • For any study in which COMIRB cannot assure subject safety and full regulatory compliance at external sites.

Step Two

If COMIRB agrees we can serve as sIRB, submit your IRB application as usual for our university and our affiliates.

Requirements for the initial submission

  • Write your protocol so it is pertinent for, and can be followed by, relying sites. If you are investigating a drug or device, use the GCP template on the COMIRB website.
  • In the Application Form, under section F(b), Non-Affiliate Performance Sites: Answer "Yes."
  • In the Application Form, under Attachment A, IRB Oversight: Answer "No" if any non-affiliated site will rely on COMIRB instead of seeking their own IRB approval. Answer the resulting questions in the smart form as appropriate. In the table labeled, "Attachment A1," list all sites for which COMIRB will serve as Single IRB and select "Pending" from the dropdown menu in the "Completed IRB Authorization" column for each site. 
  • Attach Lead IRB PI Responsibilities checklist, signed by the PI
  • Attach sIRB oversight plan,
  • Attach a "Relying Site Details" Form. Identify the PI for each relying site. Summarize the study activities taking place at the relying sites, particularly differences from other sites. View an example relying site details form.

Step Three

After COMIRB has issued initial approval, share the IRB-approved protocol and relevant study documents with the PIs at the relying sites. The relying site PIs will need to contact their IRB office to ask to rely on COMIRB. Let COMIRB know that this step has been taken and COMIRB will contact the relying IRB offices to formalize reliance documents and obtain local context information. If site-specific documents will be needed, (e.g., site-specific consent form with locally-required injury and HIPAA statements), obtain those from your relying site PIs, using the COMIRB-approved versions as templates.

COMIRB will notify you when the IRB authorization has been signed by both parties. At this point, submit an amendment to COMIRB to finalize full approval of the relying site. Include all site-specific documents requiring approval.

If there are multiple sites, it is usually best to submit amendments site-by-site due to differences in how quickly the relying sites complete their tasks.

Requirements for the amendment submission to formalize a relying site

  • Attach a Change Form and indicate a relying site is being added.
  • In Attachment A of the application form, in the table labeled, “Attachment A1,” change “pending” to “Yes” for the site being finalized.
  • Attach any site-specific documents for approval.
  • Update the “Relying Site Details” if there are applicable changes.
  • COMIRB will contact the relying IRB office and obtain a completed Local Context Form and finalize the IRB reliance agreement or SmartIRB letter. These will be added to your submission by COMIRB upon approval of the amendment.
  • If any relying investigator has a conflict of interest, attach the COI management plan from the relying institution.

When COMIRB assumes oversight for relying sites, continuing review will be required. Our PI assumes responsibility for reporting events, changes to the research, and continuing review on behalf of the relying sites.

Reportable Events

Any unanticipated problems or non-compliance at relying sites which meet COMIRB’s 5-day reporting requirements must be submitted to COMIRB by our PI and study team.

Requirements for reportable events

  • Complete and attach the Unanticipated Problem Form. Identify the site at which the event took place.
  • Attach any other relevant documents from the relying site.


Any changes to approved research at relying sites must be submitted to COMIRB for prior approval. Personnel changes at relying sites do not need to be reported to COMIRB, unless the PI changes. If the relying PI changes, COMIRB must be notified, and a new IRB reliance agreement will be executed with the new PI listed.

Requirements for amendments

  • Complete and attach the Change Form. Identify the site(s) at which the changes are being made.
  • Attach any other relevant documents from the relying site.

Continuing Review

When preparing a continuing review submission, include a report for each relying site.

Requirements for continuing review submission

  • Provide enrollment data for each relying site, i.e., enrollment status, enrollment numbers, and reasons for withdrawals (if any).
  • Disclose any unanticipated problems/noncompliance, audits, and complaints at relying sites.
  • When submitting Annual Aggregate protocol deviation or safety forms, distinguish between events at relying sites.
  • Data for relying sites can be provided as addenda for the Continuing Review Form.
  • Demographic data on enrollment may be summarized for the entire study.
  • Attach all relying site documents that need to be re-approved.
  • Attach the “Relying Site Details” form.
  • Follow all other instructions for continuing review.

Federal Policies and Regulations

NIH Single IRB Policy

The NIH sIRB policy applies to the domestic sites of NIH-funded multi-site studies where each site will conduct the same protocol involving non-exempt human subjects research. It does not apply to career development, research training or fellowship awards. Applicants must identify the single IRB during the Just-in-time submission before an award is issued.

Common Rule sIRB mandate

Since January 2020, the common rule has required single IRB review for most federally funded research involving more than one institution. Exceptions include situations where additional IRB review is required by law, including American Indian or Alaska Native tribal law, and research where the federal funder determines that a single IRB is not necessary.

Regardless of IRB review, in the conduct of the research each institution remains responsible for safeguarding the rights and welfare of human subjects. Contact COMIRB if you are seeking an exception from sIRB requirements.

Types of reliance agreements

SmartIRB Acknowledgement

If the non-affiliated site is a participating institution in the Smart IRB network, COMIRB will serve as lead IRB under the terms of the Smart IRB Agreement. Depending on the risk and complexity of the research, COMIRB may require the use of IREx to ensure clear communications between relying sites.

IRB Authorization Agreement

This agreement will be used for institutions that are not part of the Smart IRB network. It lists responsibilities for both the reviewing institution and the relying institution and requires the non-affiliated site to take responsibility for ensuring their personnel have completed required human subjects training and conflict of interest disclosures, and to report any conflicts of interest to COMIRB.

Memorandum of Understanding (MOU) or other Agreements: The University has MOUs or similar agreements for IRB review with some of the institutions and networks with which our researchers regularly collaborate. IRB Reliance Agreements may not be necessary in these cases.

Do I need to add investigators from relying sites to the Personnel form in InfoEd?

A: No. Relying sites are responsible for oversight of their employees, including training and COI disclosures.

Can I discuss IRB reliance with co-investigators at other institutions before COMIRB has approved the research?

A: Yes. However, if the relying institution will be interacting with subjects, COMIRB will not initiate a reliance agreement before the relying institution has reviewed the COMIRB-approved protocol and has completed a local context survey.

Will COMIRB serve as sIRB for multi-site research that is not NIH funded?

A: Sometimes. COMIRB is more restrictive in these cases where sIRB review is not required by federal regulation or NIH policy.

The University of Colorado Denver | Anschutz is the primary recipient of the award. Does that mean COMIRB must serve as sIRB?

A: No, COMIRB is not required to serve as sIRB. If COMIRB cannot serve as sIRB, other options include using a commercial IRB, or relying on an IRB from one of the sub-recipients of the award.

If COMIRB is serving as sIRB, are participating sites required to rely on COMIRB?

A: No, unless the research is federally funded.

Are there budget considerations for COMIRB serving as sIRB?

A: Yes, you should budget for additional PRA time for coordinating relying site approvals. You cannot direct additional funding to COMIRB. However, you can budget for a private IRB.

I received a letter from the relying IRB office stating that they have ceded review to COMIRB. Is this all I need?

A: No, an IRB authorization signed by appropriate officials at both institutions is required, and COMIRB must formally approve the addition of the site. Without both of those, the PI at the other institution does not have IRB approval to begin research activities.

If COMIRB serves as sIRB, does that mean the external PIs do not need to contact their local IRB offices?

A: No, all site PIs are always required to contact their local IRB offices about relying on COMIRB. Each local IRB office will have their own process to review the research before deciding to rely on COMIRB.

My study was approved under expedited procedures. Why Is continuing review required?

A: To help ensure adequate oversight of the research at relying sites, COMIRB requires at least annual continuing review when providing IRB oversight for a non-affiliated institution where investigators are interacting with subjects.

What is SMART IRB?

A: SMART IRB is an administrative organization supported by NCATS to help IRBs rely upon one another. SMART IRB is not an IRB. More information is available at

A relying site does not have an FWA. Can we add them to our university’s FWA?

A: No. The relying site must apply for their own FWA. The application process is on-line, and instructions are posted on the OHRP website. They will need to identify one IRB on the FWA application form, and they can name the COMIRB panel that has reviewed and approved the research.

I am from an external site that does not have an IRB. Can COMIRB serve as our IRB?

A: COMIRB can only serve as the IRB of record for a non-affiliated site when that site is directly collaborating with our university or one of our affiliates.

I am submitting a proposal to NIH, and I need a letter of support regarding the use of a single IRB. Where do I get this?

A: If COMIRB is being considered as the single IRB for your proposal, email a copy of your proposal to If the Director agrees COMIRB can serve as the single IRB, the Director will send you a letter of support. If the university is being asked to cede to another IRB, email a copy of your proposal to for a letter of support.

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