Following a randomized controlled trial that showed effectiveness of an equity-centered positive behavioral interventions and supports (PBIS) professional development intervention on student discipline in elementary schools, we studied the extent to which the intervention had differential effects on individual teachers' use of exclusionary discipline. Using the sample of teachers from the randomized controlled trial (n = 348), we assessed whether (a) changes in teacher use of office discipline referrals over the course of 2 school years and (b) intervention acceptability were moderated by teacher demographic characteristics (e.g., race/ethnicity, experience) or teacher attitudes (e.g., awareness of biases and commitment to equity). Results from multilevel models using two discipline outcomes (i.e., office discipline referrals issued to Black students and equity in office discipline referrals) did not show significant moderation effects for any demographic or attitude variables. Results of intervention acceptability found that teachers with pre-existing commitments to bias reduction found the intervention more acceptable, although means were consistently high across the sample. Findings indicate that the intervention was similarly effective on teacher discipline practices, regardless of teacher demographics or pre-existing attitudes, lending more support to the intervention's promise. [This paper will be published in "Journal of School Psychology."]