Exposure Notifications

Last updated July 1, 2022.

Available languages: Español | Tiếng Việt | 中文 | Soomaali | العربية | नेपाली 

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One of the key tools to slow the spread of COVID-19 is right in your pocket. CO Exposure Notifications is a free and voluntary service developed in partnership with Google and Apple that can alert users when they may have been exposed to COVID-19.

If you opt in to Exposure Notifications, your Android or iPhone smartphone will share anonymous tokens with other CO Exposure Notifications users using Bluetooth. If another user you’ve been near long enough to be exposed tests positive for COVID-19 within the last 10 days and enters their positive result into the service, the service will notify you. If you test positive, you can easily and anonymously notify others to stop the spread of COVID-19.

Tokens contain no personal information or location data. Everything is completely anonymous.

Knowing about a potential exposure allows you to quarantine (if necessary), get tested, and reduce the risk to your family, friends, neighbors, coworkers, and community.

Android users can download CO Exposure Notifications on the Google Play store

iPhone users can enable CO Exposure Notifications in their phone settings by finding Settings > Exposure Notifications > United States > Colorado.

Questions? See FAQ below. | Privacy policy



How your privacy is protected

  • You have full control over your participation. You can opt in to use Exposure Notifications and can turn it off at any time.
  • The service will never track your location. It uses Bluetooth, not GPS.
  • Your identity will never be revealed to anyone.
  • The service will never collect, transmit or store any of your personal information.


iPhone setup walkthrough

Android setup walkthrough
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Exposure Notifications FAQs

When two people who have activated Exposure Notifications come in close proximity to each other for a certain amount of time, their phones will exchange anonymized “tokens.” These tokens log that interaction for 10 days. If one of those two people tests positive for COVID-19 after that encounter and shares their test result in the service, the other person will receive an alert on their phone that they have been exposed to COVID-19. They will be referred to COVID-19 resources and asked to quarantine if they are not up to date with COVID-19 vaccines.

Android users can download CO Exposure Notifications on the Google Play store

iPhone users can enable notifications directly in their settings:

  1. Tap on the Settings app from your home screen​.
  2. Scroll down to locate and tap Exposure Notifications—found in the same grouping as Emergency SOS & Battery​.
  3. Tap Turn On Exposure Notifications and hit Continue​.
  4. Follow prompts to select Country and State (United States, Colorado)​.
  5. Review and accept CDPHE's terms and conditions​.
  6. When prompted, allow Exposure Notifications access to your phone's Bluetooth​.
  7. Tap "Turn On" to enable the notifications on your phone.

Awareness is key to stopping the spread of COVID-19. Exposure Notifications lets people know when they may have been exposed to the virus. This is especially helpful for people who are asymptomatic, meaning they don’t have any symptoms, but can still spread the virus. 

No. This service does not use or store personally identifiable information. It is designed to protect your privacy. The technology does not record your location or use your GPS. It uses the Bluetooth feature of your phone to exchange randomly generated anonymous “tokens” (example token:Y2RzQ0RT) that are not associated with your phone number, your name, your location, or your IP address. These anonymous tokens change every 15 minutes to protect your identity. The system uses a secure, decentralized design to determine if you have been in contact with a positive case and it is not tracked on any servers. After 10 days, or once an alert is triggered, the “tokens” are permanently erased. The code for the service is open source, so people can verify that it does not capture any personally identifying information.

No. Your personal information is not collected, stored, or shared by the exposure notification system. If you test positive for COVID-19, you have the option to share your test result in the service. If you do, anyone you have exchanged tokens with while you were infectious within the last 10 days will receive a push notification alerting them to a possible exposure, but the alert will not tell them where they were exposed or who exposed them.

Exposure Notifications’ self-report option empowers users who test positive for COVID-19 at home to quickly and voluntarily share their test results. To use this option, click “Share a Positive COVID-19 Diagnosis” in the service. On the “Enter Your Code” screen, click “Visit CO Department of Public Health and Environment’s Website.” Fill out the form to report your test result. The Colorado Department of Public Health and Environment will text you a link with a one-time verification code. If you do not receive your verification code within 48 hours, you may request a verification code by emailing CDPHE_CO_Exposure_Notifications@state.co.us.

You will be notified once the COVID-positive individual authorizes Exposure Notifications to send out an alert. You can be notified of any exposure that happened within the last 10 days. How quickly after you are exposed will also vary depending on when that person received a positive result and how quickly the information was uploaded. 

Yes. The service is compatible with similar services from certain other areas. Find a full list of compatible states on the Association for Public Health Laboratories’ Exposure Notifications’ webpage.

If you go on a trip, you can continue using Colorado as your selected state for alerts. Colorado Exposure Notifications will work with similar services in certain other areas. If you move out of Colorado for an extended period, you should review options in your new state to get local support. 

The service was designed to use Bluetooth and data minimally. It should not have a noticeable impact on battery life or data usage.

Yes. Just as you have to opt in to participate, you can opt-out at any time. 

Exposure Notifications requires several conditions to be met in order to send you a notification. Both people must have the software installed with Bluetooth enabled at the time of their close interaction. The person with a positive diagnosis must let the service know they have tested positive. Both people have to spend enough time at a close distance for there to be a likely exposure. If one of those conditions did not occur,  then you won’t get a notification. If you know that you were exposed to COVID-19 and you didn’t get a notification from your phone, you should still get tested, monitor your symptoms, and quarantine if you aren’t up to date with your COVID-19 vaccines. Visit our How to Quarantine page to learn more.

It depends on how many people you interact with for specific amounts of time and specific proximities as set by state epidemiologists and informed by CDC guidelines. The number of notifications will also depend on how many individuals use Exposure Notifications on their phones, and how many of them have a positive diagnosis. You may never receive a notification that you were exposed to a positive case.

The service is available in Spanish, English, Simplified Chinese, Arabic, Vietnamese, Amharic, and Russian.

Your positive test result will only result in your close contacts receiving Exposure Notifications if you opt in and upload your result in the service. Your personal information is not collected, stored or shared by the exposure notification system.

Yes. Exposure Notifications works alongside existing solutions available in Colorado.