Background: Although many patients with posttraumatic stress disorder (PTSD) experience a reduction in posttraumatic symptoms over time, little is currently known about the extent of their residual functional impairment. This study examines functional impairment in primary care patients with a history of PTSD as compared to patients with current PTSD, and those who never developed PTSD following exposure to trauma. Methods: The sample consisted of 321 trauma-exposed low-income, predominantly Hispanic adults attending a large urban primary care practice. PTSD was assessed with the Lifetime Composite International Diagnostic Interview and other psychiatric disorders with the SCID-I. Physical and mental health-related quality of life was assessed with the Medical Outcome Health Survey (SF-12), and functional impairment with items from the Sheehan Disability Scale and Social Adjustment Scale Self-Report. Results: Logistic regression analyses controlling for gender, psychiatric comorbidity, and interpersonal traumas showed that although patients with past PTSD function significantly better than patients with current PTSD, they experience persisting deficits in mental health-related quality of life compared to trauma-exposed patients who never developed PTSD. Overall, results revealed a continuum of severity in psychiatric comorbidity, functioning, and quality of life, with current PTSD associated with the most impairment, never having met criteria for PTSD with the least impairment, and history of PTSD falling in between. Conclusions: In this primary care sample, adults with a history of past PTSD but no current PTSD continued to report enduring functional deficits, suggesting a need for ongoing clinical attention. Depression and Anxiety, 2011.© 2011 Wiley-Liss, Inc.