In 2005-06 the Indian government introduced a new band of Community Health Workers known as Accredited Social Health Activists or ASHA workers to improve basic health outcomes through community engagement. The initial rollout of the program, between 2005 and 2009, was heavily focused on 18 "high focus Indian states", lagging behind on public health indicators. Using multiple rounds of data from the District Level House hold & Facility Survey (DLHS), I create cohorts of 12-23 month old infants, spanning a period of ten years, to establish that immunization trends of infants prior to the program were not increasing at a statistically different rate in high focus states relative to non-focus Indian states. I establish that the introduction of the program caused a sharp deviation away fro m trend in these states relative to their non-focus counterparts. I employ a difference-in-differences framework to identify the effect of t he program and use detailed public health data to control for state and time varying factors that could pose potential threats to identification. The model estimates statistically significant increases in the range of 14%-22% in the coverage of specific vaccines and the provision of full immunization in high focus states and a reduction in the percentage of infants with no immunization of up to 16%.