In September 2005, Lopez applied for a job as a scheduler at River Oaks Imaging & Diagnostic Group, using the name "Izza Lopez" on her résumé and job application. Following an interview Lopez was offered the position, subject to passing a drug screening and a background check. Lopez filled out the necessary paperwork for the checks using the name "Izza (Raul) Lopez". After Lopez had given notice at her current place of employment River Oaks rescinded the job offer. The reason give was her "misrepresentation" of herself as a woman. Lopez filed a discrimination complaint with the Equal Employment Opportunity Commission, which issued a "Notice of Right to Sue". Lopez filed suit in the United States District Court for the Southern District of Texas. Lambda Legal, an LGBT-interest public interest group, filed a discrimination lawsuit on Lopez's behalf. Lambda Legal's transgender law specialist Cole Thaler was lead attorney. Ken Upton, Lambda's senior staff attorney, assisted him.
