Early allograft dysfunction (EAD) dramatically influences graft and patient outcomes. A lack of consensus on an EAD definition hinders comparisons of liver transplant outcomes and management of recipients among and within centers. We sought to develop a model for the quantitative assessment of early allograft function [Model for Early Allograft Function Scoring (MEAF)] after transplantation. A retrospective study including 1026 consecutive liver transplants was performed for MEAF score development. Multivariate data analysis was used to select a small number of postoperative variables that adequately describe EAD. Then, the distribution of these variables was mathematically modeled to assign a score for each actual variable value. A model, based on easily obtainable clinical parameters (ie, alanine aminotransferase, international normalized ratio, and bilirubin) and scoring liver function from 0 to 10, was built. The MEAF score showed a significant association with patient and graft survival at 3-, 6-and 12-month follow-ups. Hepatic steatosis and age for donors; cold/warm ischemia times and postreperfusion syndrome for surgery; and intensive care unit and hospital stays, Model for End-Stage Liver Disease and Child-Pugh scores, body mass index, and fresh frozen plasma transfusions for recipients were factors associated significantly with EAD. The model was satisfactorily validated by its application to an independent set of 200 patients who underwent liver transplantation at a different center. In conclusion, a model for the quantitative assessment of EAD severity has been developed and validated for the first time. The MEAF provides a more accurate graft function assessment than current categorical classifications and may help clinicians to make early enough decisions on retransplantation benefits. Furthermore, the MEAF score is a predictor of recipient and graft survival. The standardization of the criteria used to define EAD may allow reliable comparisons of recipients' treatments and transplant outcomes among and within centers. Liver Transpl 21:38-46, 2015. V C 2014 AASLD.Received March 4, 2014; accepted September 2, 2014.Additional Supporting Information may be found in the online version of this article.Abbreviations: ALT, alanine aminotransferase; ALT max.3POD , maximum alanine aminotransferase value during the first 3 postoperative days; AST, aspartate aminotransferase; AUC, area under the curve; BIC, Bayesian information criterion; bilirubin 3POD , bilirubin value on day 3 after liver transplantation; CI, confidence interval; CIT, cold ischemia time; EAD, early allograft dysfunction; ECDF, empirical cumulative distribution function; ICU, intensive care unit; INR, international normalized ratio; INR max.3POD , maximum international normalized ratio during the first 3 postoperative days; MEAF, Model for Early Allograft Function Scoring; MELD, Model for End-Stage Liver Disease; OLT, orthotopic liver transplantation; PNF, primary nonfunction; POD, postoperative day; PT, prothrombin time; RI, relative import...