Background: There are national policy drivers for mental health services to demonstrate that they are effectively meeting the psychological needs of people with long-term health conditions/medically unexplained symptoms (LTC/MUS). Aims: To evaluate the implementation of a stepped-care service delivery model within an Improving Access to Psychological Therapies (IAPT) service for patients with depression or anxiety in the context of their LTC/MUS. Method: A stepped-care model was designed and implemented. Clinical and organizational impacts were evaluated via analyses of LTC/MUS patient profiles, throughputs and outcomes. Results: The IAPT service treated N = 844 LTC and N = 172 MUS patients, with the majority (81.81%) receiving a low intensity intervention. Dropout across the service steps was low. There were few differences between LTC and MUS outcome rates regardless of step of service, but outcomes were suppressed when compared to generic IAPT patients. Conclusions: The potential contribution of IAPT stepped-care service delivery models in meeting the psychological needs of LTC/MUS patients is debated.