Apply to Use NDI

Application process

The service provided by the National Death Index (NDI), part of the National Center for Health Statistics, is available solely to researchers. They can use NDI data only for statistical purposes in public health and medical studies.

To receive NDI services, researchers must first be approved by an independent advisory board. Applications are submitted through the NDI Portal, an electronic system which applicants can access after creating an account.

Check your eligibility

Before you apply, make sure your project is eligible. Carefully read the eligibility requirements and use them to evaluate your project.

Prepare and send your files

While your application is under review, you can prepare your study subjects' records for submission.

Carefully follow the instructions in Chapter 2 of the User's Guide.

When the application is approved, your project's principal investigator or project director will receive an approval package with all forms and worksheets needed for the search.

File specifications

You can provide your files using our secure File Transfer Protocol (sFTP) site. Files must be password-protected using self-decrypting software, such as PointSec, PGP, 7-Zip, or WinZip. Email ndi@cdc.gov if you need to make other arrangements to transmit your information.

Along with your files, you also must complete and submit—

• A separate NDI Transmittal Form for each file.
• A Worksheet for Calculating NDI Charges.

Receive and assess your results

NDI staff usually return your encrypted NDI search results and your original data files to you within two weeks of file submission.

Important note

Use your own assessment criteria or the suggested NDI assessment criteria to assess your results and identify the "true matches." A true match is the one that is likely to be correct for a given subject. It is your responsibility to determine which, if any, of the possible NDI matches is the correct match.

You have the option to purchase death certificates on your own directly from state vital statistics offices. You can use this option for all true matches. You also can use this option to make decisions about questionable matches, but the ultimate decision about what is "questionable" is yours.

Repeated searches (excluding reruns)

Repeated searches (excluding reruns) of NDI data must be approved by NDI staff. If your project would like to request a repeated search, the project's principal investigator must send an email to ndi@cdc.gov for the application to be unlocked.

Once the application is unlocked, the principal investigator must verify within the NDI Portal that no significant changes have occurred. If there were any changes, the application must be revised and the appropriate documentation provided. All applicants must upload the most current IRB approval letter (if applicable) and resubmit the application for review. When a repeated search is approved, project's principal investigator or project director will receive an approval package with all forms and worksheets needed for the search.

Please do not request SFTP accounts to be created unless your repeat search has been approved. When requesting the SFTP account information, please forward the last approval email to help expedite the process.

Find detailed information about repeated use of NDI data on page 4 of the application criteria document.