At the San Francisco AIDS Foundation, staff members Tyrone Clifford (left) and Rick Andrews (right) demonstrate how a contingency management visit typically begins, with a participant picking up a specimen cup for a urine sample. If the sample tests negative for meth or cocaine use, the participant has an incentive dollar amount added to their "bank" which can later be traded for a gift card. (Christopher Artalejo-Price/San Francisco AIDS Foundation)
