Percutaneous left atrial appendage occlusion (LAAO) is increasingly performed in patients with atrial fibrillation (AF). It is sometimes combined with catheter ablation (CA), either in a concomitant procedure or a staged approach. To compare the safety, efficacy, and costs of concomitant LAAO and CA versus a staged approach. The Nationwide Readmissions Database (NRD) is a nationally representative sample of all US hospitalizations, containing longitudinal patient data on almost half of all hospitalizations. The 2019 NRD was used to identify patients who underwent CA and LAAO from January to November 2019. Only patients who underwent CA and LAAO on the same date were included in the concomitant group; patients who underwent CA and LAAO on different dates or hospitalizations were included in the short-interval staged (SIS) group (within 6 months). In the SIS group, comorbidities were obtained from the first staged admission; outcomes were pooled from both procedures. Analysis accounted for the complex survey design of the NRD. Per NRD data reporting guidelines, any variable with n<10 was not reported. Out of the 25,392 patients who underwent LAAO during the study period, 191 patients underwent a concomitant procedure, and 392 patients underwent a SIS procedure. In the SIS group, mean time between the procedures was 92.4 ± 5.2 days, and LAAO was performed first in 52.3%. Patients in the concomitant group were significantly less likely to have heart failure (41.8% vs 56.5%, p=0.044), chronic obstructive pulmonary disease (11.1% vs 32.2%, p<0.01), fluid/electrolyte disorders, (<10 vs 17.5%, p=0.01), pulmonary circulation disorders (14.4% vs <10, p<0.01), and total Elixhauser comorbidities (4.1 ± 0.2 vs. 5.3 ± 0.2, p<0.01). Thirty-day readmissions (5.8% vs 4.3%, p<0.01), major bleeding (7.2% vs 19.3%, p=0.014), total length of stay (LOS) (1.8 ± 0.2 vs. 7.1± 0.6, p<0.01), and total charges ($184,566 ± $20,430 vs. $303,812± $18,308) were all significantly less in the concomitant group. After multivariate adjustment, 30-day readmissions, LOS, and total cost remained significantly different (Figure 1). Concomitant and SIS CA and LAAO procedures are performed infrequently. Patients undergoing concomitant procedures are healthier with less cardiopulmonary and overall comorbidities. After multivariate adjustment, concomitant procedures were associated with less 30-day readmissions, shorter LOS, and less total charges.