In 2009, the Supreme Court decided, in Gross v. FBL, that the law governing age discrimination should be interpreted in a stricter manner than before. After Gross, age discrimination claims are tried under but for causality in which the plaintiff's age must be the direct cause of the adverse action, as opposed to mixed motive causality allowable under Title VII, in which age would only have to be a motivating factor. Previous research has shown that but for instructions lead to more pro‐defendant verdicts, regardless of case strength, as compared to mixed motive instructions. This study reports on a simulated jury experiment that sought to uncover the influence of stereotypes concerning older workers on juror verdicts in an age discrimination case. Older worker stereotypes were assessed using the Stereotype Content Model's warmth and competence dimensions. In line with previous research, participants were more likely to find for the defendant under but for instructions, as compared to mixed motive. Further, mock jurors’ stereotypes predicted their verdicts, but only under the but for instructions, suggesting that jurors rely on stereotypes when they are limited in the case facts they can consider. Implications for policy changes and future research directions are discussed.