NYC Department of Health and Mental Hygiene | 74,894 followers on LinkedIn. Promoting and protecting the health of all New Yorkers. | Welcome to the New York City Department of Health and Mental Hygiene. With an annual budget of $1.6 billion and more than 6,000 employees throughout the five boroughs, we're one of the largest public health agencies in the world. We're also one of the nation's oldest public health agencies, with more than 200 years of leadership in the field.