Exposure Notifications

mountain background graphic with the text 'add your phone to fight COVID'

One of the key tools to fight COVID-19 and slow its spread is right in your pocket. CO Exposure Notifications is a free and voluntary service developed in partnership with Google and Apple that can notify users of possible exposure to COVID-19. 

By opting in, your Android or iPhone device will share anonymous tokens with other CO Exposure Notifications users using your phone’s Bluetooth. If another user you’ve been near tests positive for COVID-19 within a 14-day period, 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 and everything is completely anonymous.
Knowing about a potential exposure allows you to self-quarantine immediately, 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 to opt in to receive exposure notifications and can turn it off at any time.
  • The service will never track your location — it uses Bluetooth rather than 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

Exposure Notifications FAQs

Exposure Notifications relies on people opting in to the service. When two people have activated Exposure Notifications on their smartphones and come in close proximity to one another, they exchange anonymized “tokens” that log that close interaction for 14 days. If one of those two people tests positive for COVID-19 after that encounter and chooses to enable the exposure notification service, the other individual will receive an alert that they have been exposed to COVID-19. They will be directed to self-quarantine immediately and will be referred to COVID-19 resources. 

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 to access to your phone's Bluetooth​.
  7. Tap Turn On to enable the notifications on your phone.

Awareness and identification are key to stopping the spread of COVID-19. Exposure Notifications complement the current testing and case investigation process by alerting individuals of possible exposure 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. When many people have enabled Exposure Notifications on their phones, people who are asymptomatic will know they should get tested, learn they are positive for COVID-19, and quarantine until they are no longer infectious. 

No. This service does not use or store personally identifiable information and 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 IPaddress. 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 14 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 positive test result will only result in Exposure Notifications if you opt in and upload your result to the system. Even then, your personal information is not collected, stored or shared by the exposure notification system. If you test positive for COVID-19, you have the ability to share the anonymous tokens your phone has transmitted. Anyone you have exchanged tokens with in the last 14 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. 

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 14 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, people visiting Colorado from other states including Alabama, Arizona, the District of Columbia, Maryland, Nevada, North Dakota, Virginia and Wyoming will all work together. 

If you go on a trip, you can continue using Colorado as your selected state for alerts. 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. 

No. The system is designed so that a person can only upload their positive result if it is coming from qualified testing sites and labs and verified by a public health authority

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 upload their tokens. 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 quarantine and monitor your symptoms. You can find more information on how to quarantine at https://covid19.colorado.gov/are-you-sick/isolation-and-quarantine 

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 can expect to get a weekly notification from the service confirming it is still running on your phone. You may never receive  a notification that you were exposed to a positive case.

On October 25th the service will be available on Android and Apple in Spanish and in English. By November 5th the service will also be available in Simplified Chinese, Arabic, Vietnamese, Amharic, and Russian.

Yes, people using this service should still work with public health case investigators. Exposure Notifications service is designed to complement our current testing and case investigation process. Public health workers provide vital services to people in Colorado.

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

Yes, Exposure Notifications are a unique service that work alongside existing solutions available in Colorado.