omen who undergo breast reconstruction after mastectomy experience reduced psychiatric morbidity and overall greater quality of life when compared with woman who do not undergo breast reconstruction after mastectomy. 1,2 However, the timing of breast reconstruction is widely debated. Studies have shown that immediate breast reconstruction is associated with lower costs, psychosocial well-being, and superior aesthetic outcomes compared with delayed breast reconstruction. [3][4][5][6] In contrast, delayed reconstruction has been shown to have equivalent quality-oflife and patient satisfaction benefits to immediate reconstruction and lower overall and major complication rates. 7 Many surgeons advise patients to undergo delayed reconstruction if they have comorbidities or require postmastectomy radiation therapy (PMRT). Determining the proper reconstructive timing for PMRT patients is crucial because these patients are Background: Delayed-immediate autologous (DIA) breast reconstruction is a safe and flexible operative strategy for patients undergoing postmastectomy radiation therapy (PMRT). Traditionally, tissue expanders (TE) are placed in the subpectoral position, but the development of acellular dermal matrix material has led to increased use of prepectoral placement strategies. Our aim was to compare the outcomes of both TE placement strategies in DIA patients who underwent PMRT and determine whether they experienced outcomes similar to those in non-PMRT patients. Methods: A retrospective analysis of four patient groups (314 total patients) who underwent DIA reconstruction from 2012 to 2019 was performed. Ninety-eight non-PMRT prepectoral (PP), 106 non-PMRT subpectoral (SP), 39 PMRT PP, and 71 PMRT SP patients were compared. Demographics, TE complications, flap complications, and the use of large inferior skin patches were analyzed. Results: A significantly lower percentage of the PMRT PP cohort required large inferior skin patches (30.6% versus 55.7%; P < 0.05) and multiflap procedures (15.4% versus 47.9%; P < 0.001) than the PMRT SP cohort. PMRT (P < 0.0001), SP placement (P < 0.05), body mass index (P < 0.05), autoimmune diseases (P < 0.05), and bilateral mastectomy (P < 0.001) were identified as factors predictive of patients requiring a large inferior patch by means of multivariable analysis. More SP patients experienced flap postoperative breast complications compared with PP patients (35.8% versus 12.2%; P < 0.0001). Conclusion: DIA patients who undergo PMRT will require more skin and flaps if SP TE placement is chosen over PP TE placement.