The Billing Matrix Clinical Trial Management System was developed as a tool to identify clinical study participants and to serve as a potential roadmap to direct clinical trial billing activities. Charges for studies must either be directed to the participant’s insurance company as a Standard of Care (SOC) or routine charge, or to the Principal Investigator/Sponsor as an Investigational (INV) charge. The Matrix will show the timeline of the study and will indicate whether services are SOC or INV. When reviewed in conjunction with other clinical research billing documents and tools, the Matrix can direct billing procedures within a study to the correct entities. 

Medicare Coverage Analysis (MCA) is performed for trials that have a potential for billing risk beginning in 2011.

Patient enrollment is a mandated requirement from the Washington University School of Medicine administration for studies deemed to have billing risk. It is the responsibility of a designated study team member to enroll patients within 1 business day. For more information click on our FAQs (pdf) or our participant enrollment decision tree (pdf).

To obtain a user account, you must complete Billing Matrix training.

Billing Matrix grew into a Clinical Trial Management System over time with more services available. Click on the right menu to view additional services and functions.

A newer version is available which is compatible with IE11, Chrome, and Firefox. Please visit

From time to time, technical issues may arise. Here is a list of common technical issues that can occur:

  • invalid credentials when trying to sign into the Billing Matrix – can be that your user account setup is not completed.
  • when your department user login gets migrated to using your wustl-key. This can cause you to not be able to sign into the Matrix OR your study list may disappear.  Contacting us to update your Billing Matrix security will fix these issues.
  • screen looks funny, data not being saved… common causes are incompatible browsers. Having your IT department update your browsers to the most current version will help.

For these and other types of technical issues please email us at