Introduction: The annual cost of care for Atrial Fibrillation (AF) is estimated at $6.65 billion, with nearly 75% attributed to costs of hospitalizations. An AF treatment pathway with expedited follow-up to an AF-specialized clinic has been shown to reduce unnecessary admissions for AF and improve AF quality of care metrics.Goal: Evaluate differences in 30-day cost of care and discharge rate for adults presenting with AF to the emergency department (ED) before and after implementation of an AF treatment pathway.Methods: An AF treatment pathway with expedited follow-up to AF-specialized clinic was implemented at seven hospitals in North Carolina between 2017 to 2020. 30-day cost of care was calculated for patients presenting to ED with primary or secondary diagnosis of AF from 2016 to 2020 (N=12,543) by summing inflation-adjusted charges for initial hospital encounter, outpatient follow-up visits, and repeat hospital encounters for AF within 30 days. An adjusted quintile regression analysis and poisson regression, both with covariables of age, sex, race, CHA2DS2-VASc score and hospital site, were used to compare median 30 day cost of care and rates of ED discharge respectively.Results: Following implementation of the AF treatment pathway, the unadjusted median 30-day cost of care (Pre: $11,351, Post: $8,206), median initial hospital charge (Pre: $10,825, Post: $7,760), median repeat hospital encounter charge for those with repeat presentations within 30 days (Pre: $12,532, Post: $9,470) were all significantly lower (p<0.001). The adjusted median 30-day cost of care was lower (-$1532; 95% CI: $ -2001, $ -1064) and the predicted probability of discharge was greater (Pre: 61.7%, 95% CI: 60.2%, 63,2%; Post: 71.6%, 95% CI: 70.7%, 72.6%) following implementation of AF treatment pathway.Conclusions: Implementation of an AF treatment pathway in the ED is associated with an increase in ED discharge rate and decrease in 30 day costs of care.