As of September 2010, New York State (NYS) Public Health Law mandates the offer of HIV testing to all persons aged 13-64 years receiving hospital or primary care services. Changes in the number of HIV tests 13 months before and after law enactment were assessed using HIV test volume data from 166 laboratories holding NYS permits to conduct HIV testing on specimens originating in NYS. Compared with the pre-enactment baseline, overall HIV testing volume increased by 13% following enactment, with the volume of conventional and rapid HIV screening tests increasing by 12.0% and 13.7%, respectively. These data suggest that testing law is having an impact consistent with the legislative intent to increase HIV testing in NYS. Monitoring should be continued to assess testing trends across a variety of health care venues to identify and address additional barriers to HIV testing access.