INTRODUCTION: To determine the relationship between housing instability, economic standing, and access to health care and use of acute care services. METHODS: We performed a meta-regression using four nationally representative surveys. The independent variable was an ordered measure of economic and housing instability: 1) the general population, 2) low-income population, 3) never homeless users-of-subsistence-services, 4) unstably housed, 5) formerly homeless, and 6) the actively homeless. Dependent variables were four measures of health care access and three measures of acute health care utilization. RESULTS: Worsening housing instability and economic standing was associated with poorer access: being uninsured (5.4% per unit increase, 95% CI 1.7-9.2%, p=.011), postponing needed care (3.3%, 95% CI 1.9-4.7%, p=.001), postponing medications (6.1%, 95% CI 1.5-10.6%, p=.035), and with one measure of acute health care utilization: higher hospitalization rates (2.9%, 95% CI 1.2-4.6%, p=.008). DISCUSSION: Economic and housing instability should be considered a graded risk factor for poor access to health care.