The VA does not add individual ratings together to produce a combined rating. Instead, it uses a “whole person” calculation that applies each subsequent rating to the remaining able-bodied percentage. So a veteran who is 50% disabled is considered 50% able-bodied. A second rating of 30% is then applied to that remaining 50%, yielding an additional 15% disability, for a combined rating of 65%, which rounds to 70%. This means that stacking individual ratings never reaches 100% mathematically through the standard combined rating approach alone. For veterans with significant multiple conditions, understanding how the combined rating system works, and identifying all eligible conditions, including secondary conditions and TDIU, is essential to maximizing compensation.