There is now general acceptance among treatment providers that substance use disorders often have a chronic course, with afflicted individuals cycling through periods of abstinence, sporadic use, and heavy use (Hser, Longshore, & Anglin, 2007; McKay, 2009a; McLellan, Lewis, O’Brien, & Kleber, 2000). Consequently, there is considerable interest in developing new approaches to treatment that better address the cyclical and relapsing nature of these disorders (Dennis & Scott, 2007; Humphreys & Tucker, 2002; McKay, 2009a; Miller & Weisner, 2002). One such approach has been to extend the duration of treatment by adding lower intensity continuing care interventions to the back end of more intensive, stabilization-oriented treatments such as residential care and intensive outpatient treatment (Humphreys & Tucker, 2002; McKay, 2005). The main goals of these continuing care interventions are to provide ongoing support and counseling to help patients cope with stressors experienced after the initial phase of care has ended and to prevent any brief episodes of use (i.e., “slips”) from escalating into more serious relapses that could jeopardize remission status (Dennis & Scott, 2007; McKay, 2005). Although there is mounting evidence of the effectiveness of continuing care interventions (Dennis & Scott, 2007; McKay, 2005, 2009a), low retention rates in outpatient treatment remains a significant issue. For example, only 36% of admissions for substance use disorders complete intensive or standard outpatient treatment, and median lengths of stay are under 90 days (SAMHSA, 2008). Patient dropout appears to be related to a number of issues, including reduced motivation for treatment, relapse, and competing work and family responsibilities (McKay, 2009a). Unfortunately, even patients who stop attending treatment because they are doing well and feel that they do not need it anymore are still at risk for relapse and will remain so for an extended period (Anglin, Hser, & Grella, 1997; Dennis & Scott, 2007; Hser et al., 2007; Moos, Finney, & Chronkite, 1990). A recent review of the substance use disorder continuing care literature concluded that two features that were associated with effective interventions were a longer planned duration of care (i.e., at least 12 months) and more active efforts to deliver the intervention to the patient (McKay, 2009b). Some of the approaches taken included involving a spouse or partner (O’Farrell, Choqueette, & Cutter, 1998), visiting the home (Patterson, MacPherson, & Brady, 1997), using the telephone to deliver the intervention (Foote & Erfurt, 1992; McKay, Lynch, Shepard, & Pettinati, 2005), aggressively looking for patients and getting them back into treatment when necessary (Dennis, Scott, & Funk, 2003), and actively linking patients to continuing care services through case management and outreach (Coviello, Zanis, Wesnoski, & Alterman, 2006; Godley, Godley, Dennis, Funk, & Passetti, 2006). In a prior study, we examined the effectiveness of a 12-week telephone-based continuing care intervention in 359 participants dependent on alcohol and/or cocaine who had completed 4-week intensive outpatient programs (IOPs) (McKay et al., 2004, 2005). In this protocol, participants received one 15–30 minute call per week, and were also provided with a weekly transition support group for the first four weeks. The content of the telephone calls consisted of several cognitive-behavioral therapy (CBT) components, including monitoring of substance use status and progress toward selected goals, identification of current and anticipated high-risk situations, and development and rehearsal of improved coping behaviors. The telephone intervention was compared to continuing care “treatment as usual” (TAU) in these settings (two group counseling sessions per week for 12 weeks) and to a CBT relapse prevention intervention (one individual and one group session per week for 12 weeks). Self-report and biological (e.g., cocaine urine toxicology and liver function tests) data gathered over a 24 month follow-up indicated that the telephone intervention produced better substance use outcomes than TAU, as indicated by higher rates of self-reported abstinence in the full sample (McKay et al., 2005), and fewer heavy drinking days and lower GGT liver enzyme values in the alcohol dependent participants (McKay et al., 2004, 2005). Among the cocaine dependent participants, the telephone intervention also yielded lower rates of cocaine positive urine samples than CBT/RP (McKay et al., 2005). The positive effect of the telephone intervention, relative to standard care, was mediated by its effect on self-help attendance, self-efficacy, and commitment to abstinence (Mensinger, Lynch, TenHave, & McKay, 2007). The current comparative effectiveness study evaluated a new version of the telephone continuing care protocol, which was modified in several ways to better address the chronic nature of alcohol use disorders and to be more compatible with publicly funded outpatient treatment. First, the protocol was lengthened to 18 months, to provide extended therapeutic contact for patients in community-based specialty care, many of whom continue to live in environments that are not supportive of recovery. The calls were initially placed at one week intervals, with the frequency reduced to bi-weekly calls after 8 weeks, and then to monthly calls after 12 months. Second, each call began with a brief structured assessment of current risk and protective factors, which was used to determine the focus of the remainder of the session. This modification was added to facilitate tracking of risk and protective factors over time and to make sure that the content of the sessions addressed the patient’s most pressing current issues. As in the first version of the protocol, the intervention included CBT techniques such as identification of high risk situations and rehearsal of improved coping behaviors. Finally, many publicly funded programs in the Philadelphia area and elsewhere now have IOPs that provide up to 4 months of treatment, although some patients stop attending well before that point (SAMHSA, 2008). Providing continuing care only to those patients who complete these longer programs would sharply reduce the percentage of patients who would be eligible to receive that phase of care. Therefore, our modified protocol enrolled participants after they had achieved initial stabilization in IOP, at about the 3 week point, to engage them before possible dropout from IOP. While participants continued to come to IOP, the protocol included strategies to support continued attendance at IOP. Recent research has indicated that for patients with alcohol use disorders, there is therapeutic value in brief assessments (Clifford, Maisto, & Davis, 2007). Therefore, there is some question as to whether longer telephone contacts that included an actual counseling component would confer more benefit than shorter calls that consisted of a brief assessment of current symptom severity and functioning plus feedback only, with no counseling. To determine if this were the case, we included a second extended telephone contact condition in the study, which provided calls on the same schedule as the telephone counseling condition. This intervention was shorter (e.g., 5–10 minutes vs. 15–30 minutes), and did not include any of the counseling components of the full telephone intervention. Both telephone interventions were compared to treatment as usual, which consisted of up to 4 months of IOP and any step down standard outpatient care that the participants received. We predicted that (a) the continuing care interventions would produce better substance use outcomes than treatment as usual, and (b) the telephone intervention with counseling would be superior to the intervention with only monitoring and feedback. This article presents substance use outcomes during the period in which the two telephone continuing care interventions were provided (i.e., months 1–18).