Introduction: Out-of-pocket costs (OOPC) are a significant barrier to care and drive suboptimal medical therapy in ASCVD. Despite this, there is minimal attention paid to these costs in post-graduate education. To define a potential knowledge gap, we surveyed trainee understanding of OOPC. Methods: We surveyed Internal Medicine residents at a large academic program comprised of a large county safety-net hospital, a VA, and a private tertiary care hospital, about knowledge and practices surrounding patient OOPC. Residents rotate on services at all sites and the vast majority have primary care clinic at the county or VA hospital. Participants answered questions considering their most recent inpatient panel and their clinic patient panel. Familiarity was ranked on a 5-point Likert scale, and for the purposes of presentation, was divided into “Poor” and “Moderate or Better”. Non-parametric analysis was used to test differences between outpatients v inpatients and by year of training. Results: Of 159 residents, 106 (67%) responded. Familiarity with patient insurance status was moderate or better in 135 of 159 (85%). Moderate or better understanding of costs associated with medications (52% [83 of 159]), testing (19% [30 of 159]) and clinic visits (30% [48 of 159]) was less common. Respondents had higher familiarity with OOPC for clinic patients compared with their most recent inpatient panel: clinic visits (39% v 21% [62 v 33 of 159 p < 0.005]), testing (25.7% v 12.4% [41 v 20 of 159 p = 0.002]), and medications (62% v 42% [99 v 67 of 159 p <0.005]) Knowledge of cost of care was not an often-considered factor in decision making (27% “Often” or “Always” [43 of 159]). There was no significant difference in response by year of training. Discussion: Our survey demonstrates that trainee familiarity with OOPC was low overall but modestly higher for established clinic patients, perhaps reflecting longitudinal experience with them or the heterogeneity of admitted patient funding status. Familiarity with patient OOPC was not an often-considered factor in decision making and did not significantly improve over years of training. This suggests an important gap in trainee education. Teaching greater familiarity with patient OOPC during residency can increase awareness of the financial realities of patients, enabling more patient-centered care.