Introduction: Military medical preparations for future battlefields should be based on reasonable estimates of casualty numbers and triage categories. Without proper quantification and classification of casualties, it is difficult to estimate medical support requirements to include surgical capacity, logistical resupply, evacuation timing, and hospital beds. We describe a model for future medical planning and casualty categorization based on the Ukraine Surgeon General’s combat casualty data from the 1st year of the Russo-Ukraine War. Materials and Methods: Ukrainian casualty data showed a 19% Killed In Action (KIA) rate, an 81% Wounded in Action (WIA) rate, and a 54.8% Return to Duty (RTD) rate after treatment. The case severity breakdown was 16.0% severe, 39.5% moderate, and 44.5% minor. The model included the following assumptions: (1) all severe casualties require life-saving surgery in a finite period, (2) all severe and moderate cases are surgical, (3) all minor surgical cases were RTD in 1-3 weeks, (4) each operating room (OR) capacity is estimated at 10 daily cases, and (5) 20% of casualties will require blood, with proportionate use of 4-8 units for severe surgical patients, 2-4 units for moderate surgical patients, and none for minor surgical patients. These data and assumptions were applied to a standard population of 3,000 casualties to model casualty salvageability and RTD in LSCO. Results: The derived model estimates nonspecific LSCO operations will generate the following casualty categories: 20% KIA, 15% severe surgical, 20% moderate surgical, 10% minor surgical, and 35% minor non-surgical. Severe surgical patients have greatest impact on the DOW rate. Minor surgical casualties have greatest impact on the RTD rate. OR estimates for 3,000 casualties are 45 OR tables and blood usage estimates are 600-1200 units for severe surgical casualties and 400-800 units for moderate surgical casualties. The absence of sufficient theater-level hospital beds to convalesce minor surgical cases could result in up to a 10% loss of combat strength. Conclusion: This model produced similar survivability results as prior large-scale wars from 1846-1970. It has significant implications for future battlefield medical planning regarding surgical capacity, blood, hospital beds, and evacuation that might help to maximize lives saved and return to duty rates. It should be trialed and developed further in Corps-level Warfighters and other exercises of large-scale combat operations.