To resolve the issue of Touch ID not working for UnitedHealthcare, follow these steps:

1. Check Your Device Settings:
- Ensure your device supports Touch ID and it's enabled in the settings.
- Go to Settings > Touch ID & Passcode. Make sure that the toggle for iTunes & App Store and Unlock iPhone (or any specific app settings) are turned on.

2. Restart Your Device:
- Sometimes a simple restart can fix minor software glitches. Turn off your device and then turn it back on.

3. Re-enroll Your Fingerprint(s):
- Delete the existing fingerprints by going to Settings > Touch ID & Passcode and tapping on the fingerprints you want to remove. After that, add your fingerprints again by tapping Add a Fingerprint… and follow the prompts.

4. Update Your Operating System:
- Make sure your device's operating system is up to date. Go to Settings > General > Software Update and install any available updates.

5. Check Application Permissions:
- Open the UnitedHealthcare app and ensure it has the necessary permissions. You can do this by checking settings specific to the app.

6. Uninstall and Reinstall the App:
- If the issue persists, uninstall the UnitedHealthcare app and reinstall it from the App Store to ensure you have the latest version.

7. Contact Support:
- If none of the above steps work, you may need to reach out to UnitedHealthcare support for assistance. You can find the contact information on their website here - [learn more].

8. Check for Known Issues:
- Occasionally, there may be known issues with the app. Check the official UnitedHealthcare resources or news for any announcements that might relate to Touch ID problems.

If you need specific guidance tailored to UnitedHealthcare's app, further help is available on their member resource page, which outlines basic troubleshooting steps and features of the app here - [learn more].

By following these steps, you should be able to address and hopefully resolve the Touch ID issue on your device while using UnitedHealthcare's app.