
How Does the VA Calculate Combined Ratings?
Instead of adding your disability percentages together, the VA uses a “percentage of the healthy part” method. If you have a 10% disability, the VA considers you 90% healthy. A second 10% disability is applied to the remaining 90% — so 10% of 90 is 9%. Add that to your first 10% and your combined rating is 19%, which the VA rounds to the nearest 10% — so you’d be rated at 20%.
This makes it harder to reach higher ratings. For example, 50% for PTSD, 50% for sleep apnea, 20% for diabetes, and 20% for a back problem combine to 80% — even though the numbers add up to 140%. Each new rating is only applied to what is left of your “healthy” percentage.


