The U.S. Court of Appeals for the Ninth Circuit recently held in Aramark Facility Services v. Service Employees International Union that the receipt of a Social Security Administration "no-match letter" does not serve as constructive knowledge that an individual is unauthorized to work. In this case, Aramark received no-match letters for 48 employees and provided those employees with three days to correct the mismatch by providing a new Social Security Card or documentation to show that the correction process had been started. After approximately one week, Aramark fired the 33 employees who did not provide the documentation Aramark had requested. The court reviewed a single issue - whether the no-match letters and the fired employee's responses put Aramark on constructive notice that it was employing undocumented workers. The court held that constructive knowledge is to be "narrowly construed" in the immigration context and "requires positive information of a worker's undocumented status." The court ordered that the terminated workers be reinstated. After the decision, the court denied a request for an en banc review before the full court. For employers, this decision is important because it is a clear statement that merely receiving a Social Security Administration no-match letter is not enough to terminate an employee for being an unauthorized worker. However, it is important to note that this decision does not resolve the ongoing litigation arising from the Department of Homeland Security's (DHS's) "Safe Harbor" regulations published last year. In the "Safe Harbor" rule, DHS outlined a series of steps an employer should take upon receipt of a no-match letter, including giving the employer and employee 90 days to resolve the mismatch. The "Safe Harbor" rule litigation has yet to been resolved.