7 C.F.R. 246.26

WIC applicant or participant information is confidential, and state agencies must restrict the use and disclosure of confidential information to persons directly connected with the administration or enforcement of the WIC program on a need-to-know basis. 
In certain cases, confidential information may be used or disclosed for the administration of certain programs other than WIC. The chief state health officer must designate in writing the permitted non-WIC uses and the names of the organizations to which the information may be disclosed. Applicants and participants must have notice of these uses either at the time of application or the time of disclosure. 
The federal regulation makes an exception to permit disclosure to comply with a state law mandating reporting of known or suspected child abuse and with certain search warrants and subpoenas. 
The regulation provides applicants and participants a right of access to information they have provided to the WIC program, though not to information provided by third parties or program staff members. 
The regulation sets out several guidelines allowing use of nonidentifying participant and applicant information. 
Vendor and SNAP retailer information also is confidential. 

Children's Services
Economic Services

Federal regulation