 Under USERRA an employee must show that their military service was a "substantial" or "motivating factor" in the employer's adverse employment action, like firing or demotion.Since employers rarely tell reservist/employees that they are being fired because of their military service, the USERRA allows a party to establish discrimination by, among other things, examining the proximity in time between the adverse act (like firing) and the military service event (like an employee informing an employer of the employee's military obligation), whether the employer followed its internal policies, and whether the military employee was treated differently than other non-military employees.USERRA applies to all employers in the United States.