There are both free and premium tiers: <https://www.t-mobile.com/benefits/scam-shield https://www.t-mobile.com/benefits/scam-shield> The free tier seems to id

There are both free and premium tiers: <https://www.t-mobile.com/benefits/scam-shield https://www.t-mobile.com/benefits/scam-shield> The free tier seems to identify but not block likely scam calls. T-Mobile's website skews sales-heavy, and doesn't feature much technical information. The premium features appear to be app-dependent, and may not work on feature phones.