ObjectiveInterprofessional education (IPE) varies across schools/colleges of pharmacy. Long-term impact of IPE on interprofessional collaborative competencies remains uncertain despite available data on singular experiences. This study aimed to evaluate changes in pharmacy students’ collaborative abilities over the second and third professional years (PYs). MethodsStudents completed the Interprofessional Collaborative Competency Attainment Scale - Revised (ICCAS-R) after 2 large-scale interprofessional forums that occurred approximately 8 months apart. Four cohorts of students were used to examine the longitudinal change in collaborative abilities: cohort 1 (2019), cohort 2 (2020), cohort 3 (2021) and cohort 4 (2022). The ICCAS-R was used to capture data from 4 timepoints for each student in each cohort: prior to the Spring Forum in PY2 (T1), after the Spring Forum in PY2 (T2), prior to the Fall Forum in PY3 (T3), and after the Fall Forum in PY3 (T4). Using repeated measures analysis of variance, 4 total mean scores (T1 = pre1, T2 = post1, T3 = pre2, T4 = post2) were compared. ResultsFour cohorts (N = 414) completed the interprofessional forums and 336 (81%) completed the ICCAS-R instrument and were included. In each cohort, total mean scores increased T1 to T2 and T3 to T4, indicating an increase in self-assessed abilities pre/post-forum. Total mean scores decreased between T2 and T3, indicating that collaborative abilities decreased during the period between interprofessional forums. ConclusionWhile students' collaborative abilities increased around the time of the forum experiences, these changes decreased in between experiences. These findings suggest that interprofessional competencies should be reinforced at multiple time points to support enduring effects.