The ability to do contact tracing (not tracking) is theoretically there starting with iOS 13.5.
It's part of the OS, but is not enabled by default. It's also part of newer Android versions - Google and Apple worked on this together.
Now, let me tell you: PLEASE turn it ON.
It does NOT "track" you. It does not use location at all. It uses Bluetooth LE and exchanges codes with other phones that get a strong enough signal for long enough that it's likely you were within 6 feet for longer than 15 seconds (IIRC). Your random code automatically expires within 15 minutes and a new one is generated so that even if someone were purposely listening and trying to track you that way, it wouldn't work.
If you get COVID, AND your state has a contact tracing app that uses the Apple/Google COVID API, you'll get a passcode from your health authority that you put into the app to verify that you got COVID, and at that point your list of codes is uploaded and bounced to all of the other users, and their phone checks your codes against the ones they've come into contact with in the last two weeks. If there's a match, it'll alert you.
There is NO tracking of location and no personally identifying information, and the list of codes of other devices you've come into contact with is not sent off of your device unless and until you get COVID.
It's the best possible combination of technology to make contact tracing more viable and more accurate while not violating anyone's privacy. So PLEASE don't just turn it off, and please DO download your state's app if they develop one, *IF* they use the Apple/Google API. DO give it access to Bluetooth or it won't work. Do NOT give it access to your location, contacts, or any other information (and raise a stink if it even asks, because it shouldn't).
Unfortunately, I don't think it's going to be widely adopted in the US. We're too scared of Big Brother and we don't like doing our homework on this stuff, so we'll take it as an affront to our freedom and not use it, which makes it pretty useless. We'd rather kill each other.