How VA combined ratings work: why 50% plus 30% isn't 80%

One of the most common surprises in the VA system is that disability ratings are not added together. If you have a 50% rating and a 30% rating, your combined rating is not 80%. The VA uses a specific combined-ratings method that almost always produces a lower number than simple addition, and understanding it helps you set accurate expectations and spot errors.

The idea: each condition affects what's left

The VA treats you as starting at 100% efficiency. Your highest-rated condition is applied first, and each additional condition is applied only to the efficiency you have left, not to the whole 100%. Because later conditions act on a smaller and smaller remainder, they add less than their face value.

A worked example

Take ratings of 50%, 30%, and 20%. Start with the 50%, which leaves 50% efficiency. Apply the 30% to that remaining 50%, which adds 15 points for a running total of 65%, leaving 35%. Apply the 20% to that remaining 35%, which adds 7 points for 72%. The VA then rounds to the nearest 10%, giving a 70% combined rating, not the 100% you would get by adding.

Why the math matters

Combined ratings are why adding one more condition sometimes barely moves your total, and why the order and size of your ratings matter. It also explains bilateral factors and rounding, which can change the final number. If your award letter's combined rating doesn't match your own math, it is worth reviewing, because errors do happen.

Estimate yours

You can estimate your combined rating for free before you file, using the VA's own method, to understand where you stand and what a new condition would actually add. Confirm your official rating against your VA award letter, and check the VA's combined-ratings reference below.