Our agency, the Food and Nutrition Service (FNS) administers the WIC Program at the Federal level in the United States. State agencies, including the 50 States, 5 territories and 32 Indian Tribal Organizations, administer the WIC Program at the State level. We do not post all the job listings in WIC; there is not one place that lists all of both the Federal, State, and local openings related to the WIC Program.
As for Federal jobs in the health and nutrition areas, all of our agency's openings as well as other Federal agency job openings are listed on the website of the Office of Personnel Management (OPM), located at http://www.usajobs.gov
STATE AGENCY JOBS
To apply at State WIC agencies, to work in the WIC Program at the State or local level, the best thing to do is to contact the State agency directly. The mailing addresses, websites, and phone/fax numbers are located on our website at http://www.fns.usda.gov/wic-state-agency-contacts. Many of the State agencies have websites which list job openings and instructions on how to apply. If they do not have listings of job openings, you may be able to send an email to the State agency, requesting job information.
If you're looking for the human resources departments at the State level, another way to check is to find the official State government website for a given state and look for a jobs listing or for the human services department at that site. A good place to start is http://www.usa.gov/Agencies/State-and-Territories.shtml