387 Background: Immune checkpoint inhibitors (ICIs) have changed the landscape of cancer treatment over the past decade. With broaden ICIs use, internal medicine physicians are increasingly encountering them. Our study aims to assess Internal Medicine Resident’s (IMR) knowledge on immune related adverse events irAEs and identify potential gaps. Methods: We designed 21-questions pre-intervention survey assessing IMR knowledge of ICIs and associated irAEs. It assessed the following components regarding ICIs and irAEs: (1) recognition of ICIs, (2) recognition of organ systems associated with irAEs, (3) common timeframe of irAEs, (4) initial management strategies for irAEs, (5) common misconceptions about irAEs, and (6) self-rated physician comfort level on recognition/treatment of irAE. Teaching sessions by medical oncology attending and QI project team residents were conducted after survey. 21-questions post-intervention survey was sent to IMR. The results of the surveys were compared. Results: 42 of 57IMRs (73.7%) participated in pre-intervention survey, 41.5%(17) PGY1s, 29.3% (12) PGY2s and 29.3% (12) PGY3. 45 of 57IMRs (78.9%) participated in post-intervention survey, 40% (18) PGY1s, 28.9% (13) PGY2s and 31.1% (14) PGY3. Conclusions: We identified the knowledge gaps regarding ICIs and irAEs among IMRs. Educational content provided in multiple formats demonstrated increased knowledge. IMRs may benefit from web-based learning tools and algorithms on ICIs/irAEs management.[Table: see text][Table: see text]