Background: Risk predictors are an emerging tool as the need for individualized risk estimation in clinical decision-making persists. Existing risk indices have had limited success in accurately predicting hand surgery risks. This study provides a novel risk calculator for reliably predicting reoperations and readmissions in hand surgery. Methods: Hand surgeries from the National Surgical Quality Improvement Program (NSQIP) 2012-2019 database were identified. Independent predictors of 30-day unplanned reoperation and readmission were identified in the modeling sample (2012-2019) and subsequently weighted to generate a Novel Risk Score (NRS). The NRS was validated on a 2020 NSQIP hand surgery cohort and compared to the modified frailty index (mFI-5) and the modified Charlson Comorbidity Index (mCCI) with receiver operating characteristics (ROC) analysis. Results: Eighty-three thousand four hundred nine hand surgeries were identified for modeling. Reoperations and readmissions rates were 1.1% and 1.3%, respectively. Independent risk factors included male gender, inpatient status, smoking, dialysis dependence, transfusion within 72 h of surgery, wound classification, ASA class, diabetes mellitus, CHF, sepsis or septic shock, emergent case, and operative time longer than 75 min (all P < 0.05). ROC analysis of the 2020 cohort rendered an area under the curve (AUC) of 0.730, which demonstrates the accuracy of this prediction model. The mFI-5 and mCCI rendered AUCs of 0.580 and 0.585, respectively. Conclusion: We present a validated risk prediction tool for unplanned reoperations and read- missions following hand surgery that outperforms the mFI-5 and mCCI that are available online. Future studies should evaluate clinical efficacy. & REG; 2023 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.