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Stop the spread.

Add your phone to the exposure notification system to slow the spread of COVID-19 in your community. Now piloting at Washington University in St. Louis.

Mobile device with MO/Notify app icon in top left corner.

Add Your Phone

Use your phone to stay informed about your exposure risk and help slow the spread of COVID-19 in your community.


Update your iOS to version 12.5 or later.

Go into Settings, and scroll down to Exposure Notifications.

Turn on Exposure Notifications.

Select United States > Missouri.


Android users can download MO/Notify on the Google Play Store.

Get it on Google Play

How the Service Protects You and Your Community

Get exposure alerts and protect others while protecting your own privacy.

Activate or download MO/Notify on your device. Leave your Bluetooth on.

The service will exchange anonymous data with other phones in proximity to you, without sharing your identity or tracking your location.

Get an alert* if someone you were near enough for long enough tests positive — even if you don’t know them.

*In order to prevent false alerts, only lab-verified positives may be entered. Learn more.

Why Should I Participate?

  • Get alerts if you’ve been exposed. Using Bluetooth technology, MO/Notify lets you know if you’ve been in contact with someone who tests positive for COVID-19, even if you don’t know them. That means you can isolate and get tested to avoid spreading it to others.
  • MO/Notify can help keep your community safe. The more people who use the service, the more we can slow the spread of COVID-19 in our area. Not only will you get alerted if you’ve been exposed, but you can also let others know if you test positive without revealing your identity or location history.
  • Is that allergies, a seasonal cold, or COVID-19? Even vaccinated people carry some risk of inadequate protection, especially as new variants continue to emerge and researchers work to determine long-term vaccine efficacy. Knowing you’ve been exposed could keep you from harming yourself or others by dismissing your symptoms.
MO/Notify is free. There is no cost to download or use the service.

Your Data: Secure at Every Step

MO/Notify was selected and designed with privacy in mind.

  • Completely voluntary — opt in or out at any time.
  • Does not collect or exchange any of your personal information.
  • Does not track your location.
  • Only anonymous data is exchanged.

Frequently Asked Questions

How is my privacy protected?

MO/Notify does not collect or exchange any of your personal information. It does not track your location. It only logs when your device is near another device. Anonymous keys are exchanged using Bluetooth technology and are not linked to your identity or location. The keys change every few minutes to protect you. For more, view the privacy policy.

How can I join?

Android users can download MO/Notify here.

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, Missouri).
  5. Review and accept the 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.
How many notifications will I get?

It depends on how many people you are near, how many individuals use Exposure Notifications on their devices, and how many of them receive a positive diagnosis. You can expect to get a weekly notification from the service confirming it is still running on your phone.

How quickly will I be notified if I have been exposed?

You will be notified once the COVID-positive individual authorizes Exposure Notifications to send out an alert. How quickly you receive the notification will depend on when that person received a positive result and how quickly the information was uploaded. You can be notified of any exposure that happened within the last 14 days.

What happens when I get a notification?

If your device has exchanged keys with someone who reports a positive diagnosis, you will receive a push notification to alert you. This notification will include instructions on your next steps and who to contact.

The actual date of exposure to COVID-19 may be on the date listed or day prior to the date indicated in the notification. To preserve the privacy of people who use their verification codes and thus triggered your exposure verification, the MO/Notify system does not provide specific time/day information for when someone has reached high level of exposure to COVID-19. Since the time of exposure is determined at the Coordinated Universal Time, 6 hours ahead of Central Time, the day of your exposure can fall within a two-day period if it has occurred between 6 p.m. and midnight.

How can I disable exposure notifications?

Users may disable MO/Notify at any time by uninstalling the app (Android), turning off the feature (iOS), turning off the mobile device, or turning off the Bluetooth function. If the user uninstalls or deactivates MO/Notify, all anonymous keys described above that are currently stored on the device will be immediately deleted.

How does the system know if I have COVID-19?

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 I test positive, will my identity be shared with others?

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 upload your result to the system, anyone you have exchanged keys with over the past 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 (because only anonymous data was ever exchanged).

What phones can support MO/Notify?

iPhone users can use MO/Notify if they have iOS version 14.2 or later. All iPhones released starting in 2015 support iOS 14: iPhone 12, 12 Mini, 12 Pro, 12 Pro Max, 11, 11 Pro, 11 Pro Max, XR, XS, XS Max, X, SE (2nd generation), 8, 8 Plus, 7, 7 Plus, 6s, 6s Plus, SE (1st generation).

Android users can use MO/Notify if their phone supports Bluetooth Low Energy, Android Version 6 (API 23) or above, and can access the Google Play Store.

Learn more about Exposure Notifications.

What are Availability Alerts?

Availability Alerts let users know if they are in a region that is using Exposure Notifications, but is not required to receive notifications from MO/Notify.

Will exposure notifications affect my battery life or data plan?

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

Why can’t I turn on Exposure Notifications on my iPhone?

While MO/Notify does not track your location, your Location-Based Alerts need to be on for the system to know when you are close to others. To turn them on, go to: Settings > Privacy > Location Services > System Services > Turn ON Location-Based Alerts.

How can I report a technical issue with Exposure Notifications?

Technical issues can be reported to Note: Please do not send private health information via email.

How do I alert others of a possible exposure if I test positive for COVID-19?

During this pilot phase, only positive results of tests conducted by Washington University in St. Louis’ occupational health and student health services may be entered.

Why can’t I enter a positive test I get outside of WashU student/occupational health services?

The MO/Notify pilot is being conducted at Washington University in St. Louis, led by Chief Data Scientist Philip Payne at the Institute for Informatics, and relies on access to a pin key server that allows positive results to be shared anonymously. Currently those pins are not available at other testing sites.

How can I bring MO/Notify to my area or institution?

Missouri institutions and local governments interested in getting MO/Notify may contact