American Express cardholders can now use their points for Uber rides. For example, a $20 Uber ride will cost 2,000 American Express Membership Rewards points. The offer is available through an iPhone app for customers in the U.S. only.

Membership Rewards members can also choose to earn points instead of spending them when taking a ride with Uber at the rate of two points per dollar spent. Cardholders will need to tap “Enroll Me” for the Membership Rewards tie-in when prompted on the Uber iOS app and can then choose “Earn 2x Points” or “Use Points” in the Uber app for each ride.

Bottom line: An American Express partnership with VeriFone allows Membership Rewards members to pay taxi fares in some yellow cabs in New York City with their Membership Rewards points. Fares cost 100 points per dollar, so a $10 fare would cost 1,000 points. Although paying with points in this way is convenient, Membership Rewards members could get better value for their points elsewhere, so do the math.