CAC reader setup and 'reader not working' fixes
Get a reader working at home on Windows or Mac.
1. Get a compatible reader
- Use a USB smart card reader that supports the government CAC/PIV standard (many are labeled "CAC" or "PIV"; USB-C versions exist for newer Macs).
2. Plug in and let the OS find it
- Windows 10/11 and current macOS include smart card support, so most readers work without extra drivers. If the reader isn't detected, install the driver from the reader manufacturer's own site.
- Insert your CAC with the chip facing up and into the reader.
3. Install DoD certificates
Your browser must trust the DoD certificates or CAC sites will fail. Follow the certificate guide.
4. Test
- Restart the browser and open a CAC site. You should get a certificate picker and PIN prompt.
If it's still not working
- Try another USB port, and avoid unpowered hubs.
- Locked CAC (too many wrong PINs) or expired certificates can't be fixed at home. Go to a RAPIDS/ID card office (find one with the official locator below).
Official sources
Last checked Oct 13, 2026.