Cocaine-using methadone-maintenance patients were randomized to standard co
ntingency management (abstinence group, n = 49) or to a contingency designe
d to increase contact with reinforcers (shaping group, n = 46). For 8 weeks
, both groups earned escalating-value vouchers based on thrice-weekly urina
lyses: The abstinence group earned vouchers for cocaine-negative urines onl
y; the shaping group earned vouchers for each urine specimen with a 25% or
more decrease in cocaine metabolite (first 3 weeks) and then for negative u
rines only (last 5 weeks). Cocaine use was lower in the shaping group, but
only in the last 5 weeks, when the response requirement was identical. Thus
, the shaping contingency appeared to better prepare patients for abstinenc
e. A 2nd phase of the study showed that abstinence induced by escalating-va
lue vouchers can be maintained by a nonescalating schedule, suggesting that
contingency management, can be practical as a maintenance treatment.