Wash. Rev. Code § 26.23.140
The federal personal responsibility and work opportunity reconciliation act of 1996, P.L. 104-193, requires states to collect social security numbers as part of the application process for professional licenses, driver's licenses, occupational licenses, and recreational licenses. The legislature finds that if social security numbers are accessible to the public, it will be relatively easy for someone to use another's social security number fraudulently to assume that person's identity and gain access to bank accounts, credit services, billing information, driving history, and other sources of personal information. Public Law 104-193 could compound and exacerbate the disturbing trend of social security number-related fraud. In order to prevent fraud and curtail invasions of privacy, the governor, through the department of social and health services, shall seek a waiver to the federal mandate to record social security numbers on applications for professional, driver's, occupational, and recreational licenses. If a waiver is not granted, the licensing agencies shall collect and disclose social security numbers as required under RCW 26.23.150.
RCW 26.23.140