As prepectoral implant placement becomes widely adopted, recent studies investigating the use of acellular dermal matrix (ADM) during tissue expander placement have demonstrated no major benefit with regard to postoperative outcomes. We sought to evaluate second-stage outcomes 1 year after tissue expander exchange to implant with and without ADM. Consecutive patients who underwent prepectoral tissue expander-based breast reconstruction with and without ADM were identified. Patients were followed up for 1 year after tissue expander exchange to implant. Second-stage outcomes of interest including implant rippling, capsular contracture, implant explantation, additional revision surgeries, and patient-reported outcomes were collected and compared. Sixty-eight breasts in the ADM cohort and sixty-one breasts in the no ADM cohort underwent tissue expander exchange to implant. Second-stage outcomes of interest were similar between the ADM and no ADM cohorts with no statistically significant differences identified regarding incidences of implant rippling (24.6% vs. 12.1%, p = 0.08), capsular contracture (4.5% vs. 3.3%, p = 1.00), and explantation (6.6% vs. 1.7%, p = 0.67) between the two cohorts. BREAST-Q scores were similar between the two cohorts with the exception of physical wellbeing and satisfaction in terms of implant rippling, as can be seen, which improved in the no ADM cohort (p = 0.04). Our study reports no major benefit for the inclusion of ADM with respect to implant rippling, capsular contracture, explantation, need for additional revision surgeries, and patient-reported satisfaction in prepectoral second-stage implant-based breast reconstruction.