Objective: To evaluate readmissions following laparoscopic adjustable gastric banding (LAGB), laparoscopic sleeve gastrectomy (LSG), and laparoscopic Roux-en-Y gastric bypass (LRYGB). Background: Few studies have evaluated national readmission rates for primary bariatric surgery with national, bariatric-specific data. Methods: Patients undergoing primary LAGB, LSG, or LRYGB from January 1, 2014 to December 31, 2014, at 698 centers were identified based upon Current Procedural Terminology codes. The primary outcome was 30-day readmission from date of initial operation. Results: A total of 130,007 patients who underwent primary bariatric surgery were identified: 7378 LAGB (5.7%), 80,646 LSG (62.0%), and 41,983 LRYGB (32.3%). A total of 5663 (4.4%) patients were readmitted within 30 days for all causes. Patients undergoing LAGB had the lowest related readmission rate of 1.4%, followed by LSG (2.8%), and LRYGB (4.9%). Of patients who had a complication, 17.9% (n = 785) were readmitted, whereas those without readmission had a complication 1.9% of the time (P < 0.001). The most common cause of a related readmission was nausea, vomiting, fluid, electrolyte, and nutritional depletion (35.4%), followed by abdominal pain (13.5%), anastomotic leak (6.4%), and bleeding (5.8%), accounting for more than 61% of readmissions. When compared with LAGB, LSG, and LRYGB had significantly higher rates of readmission (LSG: Odds ratio 1.89; 95% confidence interval 1.52-2.33; LRYGB: Odds ratio 3.06; 95% confidence interval 2.46-3.81). Conclusions: National bariatric readmissions after primary procedures were closely associated with complications, varied based on the type of procedure, and were most commonly due to nausea, vomiting, electrolyte, and nutritional depletion.