No. Information submitted to the Department of Revenue (DOR) for purposes of claiming the Working Families Tax Credit will not be shared with any federal agencies, unless authorized by statute: “The department shall protect the privacy and confidentiality of personal data of refund recipients in accordance with chapter 82.32 RCW”. Read the complete statute here: RCW 82.08.0206.
Additionally, information provided to DOR in applying for the WFTC is considered confidential tax information and DOR may only disclose it as authorized by RCW 82.32.330. This includes information about citizenship or immigration status, which DOR is prohibited from disclosing by law. See RCW 43.17.425.