Apple Inc. and Alphabet Inc.'s Google said the ability to use contact tracing without an app will roll out to iPhones on Tuesday and Android devices later this month.
The companies said this will increase adoption of the system, which has begun to identify COVID-19 exposures. While it does not require an app, it will only work in regions where public health authorities offer apps.
Apple included the update in a test version of its iOS software last week. It becomes widely available on Tuesday with the release of iOS 13.7. The capability, known as Exposure Notifications Express, will also work on Android devices running version 6.0 and later.
The technology giants said 25 U.S. states, territories and Washington DC are exploring exposure notification systems, which would cover more than 55% of the US population. Just six states have launched the system so far and it has been rolled out in 20 countries and regions.
"As the next step in our work with public health authorities on Exposure Notifications, we are making it easier and faster for them to use the Exposure Notifications System without the need for them to build and maintain an app," the companies said in a statement.
Virginia, Washington DC, Nevada and Maryland will be the first to roll out contact tracing without the need for an app. More states will add support later this year, the companies said.
Without an app, the system is maintained inside of the Settings apps on Apple and Android devices. Like with the initial approach, it uses Bluetooth to determine how close and for how long a user is from another person. If a user inputs into their device that they have tested positive for Covid-19, a person with a phone that met the threshold based on time and distance will be notified of a possible exposure.