In 2010 New York passed state legislation that required providers to offer HIV testing and linkage to care to all patients aged 13-64 years seeking routine medical care in all settings, including emergency departments and hospitals. Previous studies have looked at the effect of the 2010 HIV testing law on testing volume and HIV diagnoses, but have not examined how the state policy affects acute care utilization and outcomes. A differences-in-differences regression model was developed using hospital discharge records collected from New York and Florida by the Healthcare Cost and Utilization Project from 2008-2012. The model evaluated whether the presence of the 2010 HIV testing law in New York has had an effect on HIV-related hospital admissions in the two years before and after its implementation, using Florida as a comparison. The results of our analysis indicate that the 2010 HIV testing law decreased the percentage of hospital admissions that were HIV-related by 0.07 percentage points, when controlling for patient characteristics in addition to state, hospital and year effects. Although statistically significant, the small magnitude of the estimated effect suggests that state policymakers seeking to reduce acute care utilization for patients with HIV should supplement such laws with other policies or funding programs. These might include support for either more effective implementation of the mandate or programs that provide outreach, support, and treatment for HIV patients. Future studies should examine the long-term effects of the HIV testing law on acute care utilization or look at the effect on utilization of services in outpatient settings.