Among heterosexual providers, implicit preferences always favored heterosexual people over lesbian and gay people. We characterized the sample with descriptive statistics and calculated Cohen d, a standardized effect size measure, with 95% confidence intervals. We examined attitudes toward heterosexual people versus lesbian and gay people in Implicit Association Test takers: 2338 medical doctors, 5379 nurses, 8531 mental health providers, 2735 other treatment providers, and 214 110 nonproviders in the United States and internationally between May 2006 and December 2012. We examined providers’ implicit and explicit attitudes toward lesbian and gay people by provider gender, sexual identity, and race/ethnicity.