Tissue-expander (TE) placement followed by implant exchange is currently the most popular method of breast reconstruction. There is a relative paucity of data demonstrating patient factors that predict complications specifically by stage of surgery. The present study attempts to determine what complications are most likely to occur at each stage and how the risk factors for complications vary by stage of reconstruction. A retrospective chart review was performed on all 1275 patients who had TEs placed by the 2 senior authors between 2004 and 2013. Complication rates were determined at each stage of reconstruction, and these rates were further compared between patients who had pre-stage I radiation, post-stage I radiation, and no radiation exposure. Multivariate logistic regression was used to identify independent predictors of complications at each stage of reconstruction. A total of 1639 consecutive TEs were placed by the senior authors during the study period. The overall rate for experiencing a complication at any stage of surgery was 17%. Complications occurred at uniformly higher rates during stage I for all complications (92% stage I vs 7% stage II vs 1% stage III, P < 0.001). Predictors of stage I complications included increased body mass index [odds ratio (OR), 1.04; 95% confidence interval (CI), 1.01-1.07], current smoking status (OR, 3.0; 95% CI, 1.7-4.8), and higher intraoperative percent fill (OR, 3.3; 95% CI, 1.7-6.3). Post-stage I radiation was the only independent risk factor for a stage II complication (OR, 4.5; 95% CI, 1.4-15.2). Complications occur at higher rates after stage I than after stage II, and as expected, stage III complications are exceedingly rare. Risk factors for stage I complications are different from risk factors for stage II complications. Body mass index and smoking are associated with complications at stage I, but do not predict complications at stage II surgery. The stratification of risk factors by stage of surgery will help surgeons and patients better manage both risk and expectations.