Background: Allergic and infusion-related reactions represent a significant portion of reported adverse drug reactions (ADRs) at The University of Kansas Health System (TUKHS) Cancer Center sites. According to the TUKHS Allergy Documentation policy, all observed reactions are required to be documented in the electronic health record (EHR) and reported to the responsible provider. Insufficient documentation may result in preventable patient harm due to continued exposure to medications after known ADRs. An audit of patient EHRs demonstrated notable variability in documentation practices, which served as the impetus to implement a standardized ADR documentation workflow at Cancer Center sites. Methods: This multi-center, retrospective study included patients with ADRs submitted via safety reports from July 1st, 2022 to April 1st, 2023. Categorical data was analyzed using the chi-squared test. Duplicate reports and ADRs identified as side-effects were not included in the final analysis. Targeted education was provided via two online video modules, a workflow tips sheet, and an educational infographic. The primary outcome was frequency of allergy lists updated following submission of a safety event report. Secondary outcomes included frequency of standardized progress note writing, note routing, and accurate reaction type differentiation. Results: Targeted education significantly improved allergy list updating from 34.2% to 84.0% (P < 0.001), use of a standardized progress note from 47.4% to 64.2% (P = .008), and correct differentiation of reaction type from 57.7% to 76.4% (P = .02). Progress notes were routed to the responsible provider 58.5% of the time. Smaller community-based Cancer Center sites were significantly less likely to update allergy lists (7.5% vs. 24.5%, P = .017) and more likely to document incorrect reaction types (35.0% vs. 14.3%, P = .022). Conclusions: Targeted education for a standardized documentation workflow increased adherence to ADR documentation, ensuring future treatment plans are updated for patients with a history of reaction and the EHR accurately reflects ADR history. There is an opportunity to strengthen targeted education surrounding ADR documentation workflows for smaller community-based sites.