National Flat File for COVID-19

The National Flat File (NFF) is an electronic reporting method for laboratories to submit COVID-19 results to public health. NFF meets laboratory notifiable condition reporting requirements in Washington State and includes entry-fields for the new HHS COVID-19 reporting requirements.

Washington State law requires laboratories to report (i.e. fax) all COVID-19 results to the local health jurisdiction of the patient's residence; this includes positive, negative, inconclusive, and other results.

Jurisdiction contact information can be found on this webpage:

NFF reporting meets requirements for laboratories as defined under the Washington Administration Code (WAC) Chapter 246-101 and should only be used for COVID-19 results reporting.

How was NFF established?

The Association of Public Health Laboratories (APHL) developed the National ELR Flat File and HL7 Generator Tool - dubbed NFF.

How is NFF used?

The HLT Generator is a tool based in Microsoft Excel used to generate an HL7 V2.5.1 ELR R1 specification-based data output file for COVID-19 test results. It is compliant with all data format and value constraints imposed by the CDC and HHS.

Are NFF and ELFF the same?

No. NFF is a standardized CSV file format based on ELFF. The DOH ELR team is no longer accepting applications for ELFF.

Is using NFF faster than using ELFF or ELR?

Yes. The onboarding process and content validation are faster using NFF.

May I use ELR instead of NFF for COVID-19 reporting?

If your organization is able to generate HL7 messages without the aid of NFF, then yes.

If you are already using ELR for other notifiable conditions, email and let us know before adding COVID-19 to your production feed.

Helpful Guidance for using NFF:

Faxing: Until the entire NFF onboarding process is complete, it is imperative to continue reporting (faxing) all COVID-19 results to the local health jurisdiction where the patient resides.

If your organization is not a laboratory, and you are reporting point of care (POC) tests, see your reporting options at: Reporting COVID-19 Test Results for Point-of-Care Testing Facilities :: Washington State Department of Health.

All other test results must be faxed.

Upon successful completion of the NFF onboarding process, laboratories no longer need to fax COVID-19 results. The ELR team will send a confirmation when faxing can stop.

Listserv: The ELR team has created a listserv to provide general information about Washington specific electronic laboratory reporting, national updates, frequently asked questions, and future listening sessions. Emails will be sent out as needed and average about one email per week. Subscribe to the listserv.

FAQs: To address COVID-19 news on federal and state requirements, DOH created an FAQ page specific to reporting COVID-19 test results.

NFF Onboarding Process

1. Complete the registration form

To begin, complete the registration form. The ELR onboarding team will reply to your form by email.

2. Select an NFF format

Choose the NFF format that works best for your laboratory. You can either:

  • Manually enter data into the NFF spreadsheet
  • Use a report writer to develop an automated data file

Both formats have been carefully developed to load into our surveillance system, and we do not accept other formats.

3. Create your test file

In the downloaded toolkit, APHL has included instructions and advice for creating and validating your files. They have already provided walkthrough videos for using the national flat file.

Once you have a test file ready, follow APHL's directions to run the file through the NIST validation tool. We recommend downloading the tool to protect confidential information in your test file. When you have a clean NIST report, email the NIST report PDF as an attachment to the ELR team.

Please do not email your test file with personally identifiable information.

4. Set-up transport

Once we receive your NIST report, the ELR team can help set up your preferred NFF transport method that works best for your agency. Your options are:

  • APHL Informatics Messaging Services (AIMS) via APHL. Laboratories who use AIMS may submit all their testing data, and AIMS will route results to the appropriate states. Please work with APHL directly if you are interested in this option.
  • OneHealthPort Health Information Exchange (HIE) is DOH's preferred ELR transport method. If you already have an account or are considering reporting notifiable conditions beyond COVID-19, this is your best option.
  • Secure File Transfer (SFT) is free transport option for COVID-19 only reporting, and the ELR staff will submit your set-up request when you have a test file for review.

These are the only methods you can use to submit NFF data. Do not email personally identifiable information.

5. Structural validation

Once your laboratory has developed a file using one of the NFF formats, submit a sample file through the transport method you selected.

While we are moving your test file into our WA Disease Reporting System onboarding platform, you may receive emails on structural errors that need to be resolved.

6. Content validation

When the data is in WDRS onboarding, we will perform content validation to ensure data fields are entered correctly. The onboarding team will work with you on any further edits. During the validation process, the onboarding team may ask you to submit additional data files to ensure your file can be successfully processed before moving into production.

7. Submit COVID-19 results via NFF

The ELR onboarding team will give you the green light to move into parallel production for two weeks. During this time, we request that you continue to fax results while submitting data electronically. Once we confirm everything looks good, we will work with you to identify a cut-off time to begin submitting COVID-19 results by NFF so you can stop faxing results. We will also walk you through the process of submitting backlog results.

Contact Information

For questions about NFF or ELR, please contact