The effects of COVID-19 on breast reconstruction included shifts towardalloplastic reconstruction methods to preserve hospital resources and minimize COVID exposures. We examined the effects of COVID-19 on breast reconstruction hospital length of stay (LOS) and subsequent early postoperative complication rates. Using the National Surgical Quality Improvement Program, we examined female patients who underwent mastectomy with immediate breast reconstruction from 2019 to 2020. We compared postoperative complications across 2019-2020 for alloplastic and autologous reconstruction patients. We further performed subanalysis of 2020 patients based on LOS. Both alloplastic and autologous reconstruction patients had shorter inpatient stays. Regarding the alloplastic 2019 versus 2020 cohorts, complication rates did not differ (p > 0.05 in all cases). Alloplastic patients in 2020 with longer LOS had more unplanned reoperations (p < 0.001). Regarding autologous patients in 2019 versus 2020, the only complication increasing from 2019 to 2020 was deep surgical site infection(SSI) (2.0% vs. 3.6%, p = 0.024). Autologous patients in 2020 with longer LOS had more unplanned reoperations (p = 0.007). In 2020, hospital LOS decreased for all breast reconstruction patients with no complication differences in alloplastic patients and a slight increase in SSIs in autologous patients. Shorter LOS may lead to improved satisfaction and lower healthcare costs with low complication risk, and future research should examine the potential relationship between LOS and these outcomes.