The results indicated that changing to new treatment providers in three in-prison therapeutic community (TC) treatment facilities caused significant disruptions, leading to decreased client-counselor rapport and peer support as well as lower levels of treatment readiness, participation, and satisfaction of clients. Corrections officials use private contractors to operate in-prison TC treatment programs. The competitive bidding process for services sometimes results in a treatment-provider change. Three in-prison TC programs from a larger sample of 26 programs participating in the study later became subject to treatment and staff operational changes when a new treatment-provider organization assumed management of their operations. In each case, the new provider displaced the existing provider that had been delivering TC treatment in these programs for more than a decade. In an effort to evaluate the impact of this transition on clients over time, a second cross-sectional of the Criminal Justice Client Evaluation of Self and Treatment (CJ CEST) was administered. Using the data collected, quantitative assessments of client functioning were made at two points in time. Findings suggest that careful planning is needed to cultivate or maintain therapeutic integrity of TC programs during transition periods especially to limit the negative impact that these changes can have on the client and staff of well functioning programs. This study emphasized the need for intentional planning and monitoring program functioning both at the client and program levels during critical periods of provider transitions; however, there is also value in making performance monitoring a permanent feature of all treatment programs. Table, references