Data Requests

Thank you for your interest in requesting data from the Washington Emergency Medical Services Information System (WEMSIS). WEMSIS is the Washington State data repository for EMS responses.

General data details to consider:

  • Each record in WEMSIS pertains to a single response by an EMS unit. If you desire patient level data, be mindful that you may receive records from multiple EMS units dispatched to the same patient at a single incident. These records often do not share the same incident number but could be linked using patient and scene information.    
Year Estimate Percent of EMS Records in WEMSIS
2018 71-74%
2019 74-77%
2020 81-90% 
2021 90-91% 
2022 91-92% 
  • Data submitted to WEMSIS follow the standard of the national EMS data system, NEMSIS. For information on what data may be available, see the NEMSIS Version 3.5 Dictionary (PDF).
  • Data fields will vary in how often they are documented. Any field classified by NEMSIS as “Mandatory” or “Required” will be documented more often, while fields marked “Recommended” or “Optional” will be less complete. See the WEMSIS Data Quality Report for more information on completeness of select fields. 
  • Per RCW 70.168.090, data elements related to the identification of individual patient's, provider's and facility's care outcomes are considered confidential, and may require a data sharing agreement or approval from the Washington State Institutional Review Board (WSIRB).For information on the WSIRB review process, please visit Human Research Review Section | DSHS (  

EMS Opioid Data

EMS is often the first contact with persons needing emergency care related to opioid use.  In response to increased requests for current opioid data at the county level, the WEMSIS Data Request Team has developed two opioid data tools available to request through the data request process below.

  • WEMSIS Quarterly Opioid Analytic Dataset
    • An analytic dataset with limited opioid data for public health projects use.
    • Data Sharing Agreement required
    • Data update frequency limits (e.g. updated quarterly). 
  • WEMSIS Opioid Continuous Quality Improvement (CQI) Report
    • Online portal access for individual patient data for substance abuse follow-up as described in RCW 70.168.090(2)
    • Use of this tool for any purpose other than providing patient support as described in RCW 70.168.090(2) or for use in mortality review is not permitted.
    • Data sharing agreement and confidentiality agreement required 

For more information about WEMSIS EMS Opioid Data Tools, including record selection criteria and data dictionaries please contact us via email (

To start a data request or gain access to one of the data tools above or other WEMSIS data, submit the form below. We will follow up regarding next steps within five business days. Please be detailed and ensure all contact information is correct before submitting your request.   

If you have any other questions, feel free to contact us. Thank you. 

Submit a Data Request