We recommend that the New York State Department of Health ensure that improvements made to its processes for determining whether an individual applying for Medicaid has already been assigned a Medicaid ID number are effective by verifying that: - system queries are adequate to identify all individuals with existing Medicaid ID numbers and - local district and Marketplace staff are following guidance on identifying individuals with Medicaid ID numbers and using all available resources to identify and prevent the issuance of more than one Medicaid ID number to the same individual.