In a landmark ruling, the Equal Employment Opportunity Commission (EEOC) held that an employee alleging discrimination based on sexual orientation states a viable claim under Title VII of the Civil Rights Act of 1964. The EEOC’s decision marks the first time the agency explicitly held that Title VII’s prohibition on discrimination “because of sex” can be extended to lesbian, gay and bisexual (LGB) employees.

A temporary employee with the Federal Aviation Administration (FAA) alleged that his supervisors refused to offer him a permanent position because of his sexual orientation. The employee is a gay man, and claimed his immediate supervisor regularly made derogatory comments to him about his orientation. The FAA dismissed the complaint through its internal administrative procedures, finding that the full-time position was never filled, and therefore no discrimination took place. The FAA further held the employee did not raise his complaint in a timely fashion with an EEO Counselor, as required by agency regulations. The employee appealed the decision to the EEOC.

After acknowledging that the language of Title VII does not mention sexual orientation, the EEOC reasoned that nothing in Title VII excludes LGB employees from Title VII’s protections. The EEOC went further, finding discrimination based on sexual orientation is necessarily “based on” sex, because orientation “as a concept cannot be defined or understood without reference to sex.” Therefore, “sexual orientation is inseparable from and inescapably linked to sex.” Additionally, citing numerous federal courts’ decisions, the EEOC found that orientation discrimination constitutes “sex stereotyping.” Employers cannot take adverse employment actions based on their expectations of how a woman or man should act. Finally, the EEOC found that orientation discrimination may constitute “associational discrimination,” as it is based on an employee’s romantic association with a member of the same sex.

Employers should expect to see an increase in Title VII claims of sexual orientation discrimination. Many federal district courts have already held that sexual orientation is protected; more will follow as courts often defer to the EEOC’s interpretation of Title VII. Meanwhile, lawmakers in Congress recently introduced the Equality Act of 2015, prohibiting sexual orientation discrimination in housing, education, and employment. Speaker of the House John Boehner has not indicated he would bring the bill up for a vote. But the EEOC’s latest ruling may lead to a national, court-enforced prohibition against sexual orientation discrimination in employment. The Illinois Human Rights Act already prohibits Illinois employers from discriminating against employees based on sexual orientation and gender identity. Employers nationwide and in states without LGBT anti-discrimination laws should develop best practices to ensure a welcoming workplace and avoid costly litigation.