Background
The U.S. Federal government leverages Personal Identity Verification (PIV) identity cards for its employees and contractors. The Department of Defense (DoD) implements PIV through Common Access Cards (CACs). These cards hold digital identities in the form of Public Key Infrastructure (PKI) certificates, which enable the holders to cryptographically verify their identity and perform other functions, such as encrypting and digitally signing content.
How Do I Find My PIV ID?
Your 16-digit unique ID is attached to your DoD issued PKI certificates, which are stored on your CAC. To extract your PIV ID, please follow these steps, which should be completed on any computer with a card reader (such as your DoD issued laptop).
In most cases, PIV IDs are permanent regardless of CAC issuance. New CACs (and certificates) will maintain the same PIV ID. The exception is for a limited subset of users, primarily National Guard and Reserve members, who may hold both a military CAC and contractor CAC simultaneously, in which case each card will have a unique PIV ID.
- Insert your CAC into the reader.
- In the Windows Search bar, enter "Internet" and select "Internet Options"

- Navigate to the Content tab and select Certificates
- Find your certificate where the Issued By column starts with DOD ID select it and click View

- Navigate to the Details tab and scroll down until you find the field named Subject Alternative Name. Select that field.
- Your PIV ID should be displayed under next to Principal Name= and ends at the @mil. Copy down only the integers in that field, in the below example the PIV ID is 1266028411197005.

When asked for your PIV ID, only the 16 digits should be included, the @mil is superficial and should be neglected.