The ACK Facts: Truths About eMDR Acknowledgement Files

The ACK Facts: Truths About eMDR Acknowledgement Files

Adonna Blasko, Marketing Manager, Pilgrim Quality Solutions

When it comes to adverse event reporting and eMDR, understanding how things work plays a role in your organization’s success. This is especially true with acknowledgement files (ACKs), as they determine whether you have met your regulatory reporting requirements.

FACT: There are 3 separate acknowledgement files to identify various parts of the eMDR process. Each acknowledgement relates to a different part of the process. Without separating them, it would be more difficult to identify failure points, and therefore more difficult to resolve data or file discrepancies.


  • Sent after the FDA Electronic Submission Gateway (ESG) receives the eMDR file
  • Also known as the “receipt” or “MDN” (message disposition notification)


  • Sent after CDRH receives the eMDR file
  • Signifies the file was sent to the appropriate agency within FDA


  • Sent after the eMDR file loads into the CDRH database

ACK3, Scene 2:

  • ACK3 includes two files — an HTML which is human-readable, and an XML.
  • The FDA has declared that either file returned from CDRH for ACK3 must be saved as evidence during an FDA inspection.

FACT: The FDA uses ACK 1 to determine if you have met your regulatory reporting deadline. However, it only counts toward your deadline if you receive ACK 3 with no issues. Additionally, FDA only considers the date stamp of ACK 1, accounting for the different time zones for different manufacturers or importers. If there is a problem with your file, or with loading into CDRH systems, your eMDR will need to be resubmitted. This will begin the process requiring 3 acknowledgement files again. If you are submitting multiple eMDRs in one batch, you need only resubmit the particular report with an error, not the entire batch.

FACT: You should plan to monitor your ACKs. Remember that the timestamp on your first acknowledgement will only count once the file loads successfully into CDRH systems (ACK 3).  One must always be attentive to whether the organization’s eMDRs are accepted successfully. With proper monitoring, any errors can be corrected within your regulatory reporting deadlines.

FACT: You can also receive a negative acknowledgement. A negative acknowledgment demonstrates that your file did not load properly, or the HL7 format was incorrect. It could mean that your organization’s or the FDA’s servers were down at the time you submitted your file. For ACK 3, it signifies the MDR HL7 message has the wrong format. The report file will need to be corrected and resubmitted within your reporting timeframe.

FACT: If you are experiencing issues submitting your eMDR files, you should contact the CDRH via email ( for assistance. FDA recommends waiting 24 hours before contacting them if the issue is with the third acknowledgement.

Now that you know the ACK facts, you’re on track to get the knack of receiving, storing, and handling ACKs. Use this knowledge to help your organization better manage compliance.


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Adonna Blasko

Marketing Manager, Pilgrim Quality Solutions