Practitioners expected the Affordable Care Act (ACA) to increase availability of health services and access to treatment for Americans with substance use disorders (SUDs). Yet research has not examined the associations among ACA enrollment mechanisms, deductibles, and the use of SUD treatment and other healthcare services. Understanding these relationships can inform future healthcare policy. We conducted a longitudinal analysis of patients with SUDs newly enrolled in the Kaiser Permanente Northern California health system in 2014 (N = 6957). Analyses examined the likelihood of service utilization (primary care, specialty SUD treatment, psychiatry, inpatient, and emergency department [ED]) over three years after SUD diagnosis, and associations with enrollment mechanisms (ACA Exchange vs. other), deductibles (none, $1-$999 [low] and ≥$1000 [high]), membership duration, psychiatric comorbidity, and demographic characteristics. We also evaluated whether the enrollment mechanism moderated the associations between deductible limits and utilization likelihood. Service utilization was highest in the 6 months after SUD diagnosis, decreased in the following 6 months, and remained stable in years 2-3. Relative to patients with no deductible, those with a high deductible had lower odds of using all health services except SUD treatment; associations with primary care and psychiatry were strongly negative among Exchange enrollees. Among non-Exchange enrollees, patients with deductibles were more likely than those without deductibles to receive SUD treatment. Exchange enrollment compared to other mechanisms was associated with less ED use. Psychiatric comorbidity was associated with greater use of all services. Nonwhite patients were less likely to initiate SUD and psychiatry treatment. Higher deductibles generally were associated with use of fewer health services, especially in combination with enrollment through the Exchange. The role of insurance factors, psychiatric comorbidity and race/ethnicity in health services for people with SUDs are important to consider as health policy evolves.