Adoption of early mobility interventions into intensive care unit (ICU) practice has been slow and varied. To examine factors associated with early mobility performance in critically ill adults and evaluate factors' effects on predicting next-day early mobility performance. A secondary analysis of 66 ICUs' data from patients admitted for at least 24 hours. Mixed-effects logistic regression modeling was done, with area under the receiver operating characteristic curve (AUC) calculated. In 12 489 patients, factors independently associated with higher odds of next-day mobility included significant pain (adjusted odds ratio [AOR], 1.16; 95% CI, 1.09-1.23), documented sedation target (AOR, 1.09; 95% CI, 1.01-1.18), performance of spontaneous awakening trials (AOR, 1.77; 95% CI, 1.59-1.96), spontaneous breathing trials (AOR, 2.35; 95% CI, 2.14-2.58), mobility safety screening (AOR, 2.26; 95% CI, 2.04-2.49), and prior-day physical/occupational therapy (AOR, 1.44; 95% CI, 1.30-1.59). Factors independently associated with lower odds of next-day mobility included deep sedation (AOR, 0.44; 95% CI, 0.39-0.49), delirium (AOR, 0.63; 95% CI, 0.59-0.69), benzodiazepine administration (AOR, 0.85; 95% CI, 0.79-0.92), physical restraints (AOR, 0.74; 95% CI, 0.68-0.80), and mechanical ventilation (AOR, 0.73; 95% CI, 0.68-0.78). Black and Hispanic patients had lower odds of next-day mobility than other patients. Models incorporating patient, practice, and between-unit variations displayed high discriminant accuracy (AUC, 0.853) in predicting next-day early mobility performance. Collectively, several modifiable and nonmodifiable factors provide excellent prediction of next-day early mobility performance.