LOADING
The VA does not add your disability ratings together. Under 38 C.F.R. § 4.25, the VA uses a "combined ratings table" that applies each rating to your remaining "healthy" percentage. Per M21-1, Part IV.ii.2.A, the RVSR applies ratings in descending order from highest to lowest.
Under 38 C.F.R. § 4.26, when you have disabilities affecting both sides of the body (both knees, both arms, left knee and right hip, etc.), the VA adds a "bilateral factor" of 10% of the combined bilateral rating before combining with non-extremity conditions. This can push you over a rounding threshold.
The VA rounds to the nearest 10%. Per 38 C.F.R. § 4.25, combined values ending in 5 or higher round up, below 5 round down. This means 74.5% rounds to 70%, but 75% rounds to 80%. This is why every percentage point matters and why secondary conditions at even 10% can push you over a rounding threshold worth hundreds of dollars per month.
Understanding VA math reveals two critical strategy points. First, each additional rating has diminishing returns because it's applied to a smaller remaining healthy percentage. Second, the most impactful ratings are the first ones — getting from 0% to 50% is a bigger jump than 50% to 70%. But small secondary claims (10-20%) can push you past critical rounding thresholds (e.g., from 74% to 76%, which rounds to 80%).