Ratings Are Based on the Severity of the Disability
VA rates each service-connected disability to reflect the impairment of earning capacity caused by that disability. The agency uses a “Rating Schedule of Disabilities,” which groups disabilities by body system. VA's rating schedule has hundreds of diagnostic codes covering almost all types of diseases and injuries. 38 CFR Book C, Subpart B. Each diagnostic code lists several sets of medical signs and symptoms, with each set linked to a particular disability rating percentage. Not all diagnostic codes go up to 100%. For example, loss of use of a foot, because of amputation or other reasons, is assigned a 40% rating. The highest possible rating for migraine headaches is 50%. It is possible to have a 0% rating for a service-connected disability. The ratings are intended to reflect the average impairment in earning capacity, and individual circumstances are not considered.
Many diagnostic codes have ratings in 20% or 30% increments. For example, mental disorders are evaluated at 0%, 10%, 30%, 50%, 70% and 100%. The Ratings Schedule can be found at
https://www.benefits.va.gov/WARMS/bookc.asp
What if I have more than one service-connected disability?
If a veteran has more than one service-connected disability, VA uses the Combined Ratings Table to calculate an overall or "combined" disability rating. This combined disability rating, which ranges from 0% to 100%, determines the amount of the monthly disability payment from VA. Theoretically, the combined rating is intended to reflect the reduction in earning capacity caused by all of the service-connected impairments. It is important to remember that the combined rating is NOT calculated by simply adding all the individual ratings together. So, for example, if a veteran has a 70% rating for depression and a 50% rating for migraines, the combined rating would be 90%, not 120%.
This is how VA reaches the 90% combined rating. VA assumes that a veteran with no service-connected disabilities has 100% of his or her earning capacity. In our example, the depression (rated at 70%) reduces the veteran's earning capacity by 70%. If this were the only service-connected disability, the veteran's rating would be 70%.
Because there is another service-connected disability, VA calculates the additional reduction of earning capacity resulting from the migraines. Since the depression reduces the veteran's earning capacity by 70%, the remaining earning capacity is 30% (100% -70%).
VA then calculates the effect of the migraines on the veteran's remaining earning capacity of 30%. Because the migraines are rated at 50%, they reduce the veteran's remaining earning capacity of 30% by that proportion. This means the migraines reduce the total earning capacity by an additional 15%: 50% (rating for migraines) of 30% (remaining earning capacity) = 15%.
VA adds this 15% additional reduction in earning capacity caused by the migraines to the 70% reduction in earning capacity resulting from the depression to reach a total reduction of earning capacity of 85%. Ratings are assigned in multiples of 10, so VA then rounds up and assigns a combined rating of 90%.
Total Disability for Individual Unemployability (TDIU or IU)
Veterans may be eligible for a total, 100% rating even if their combined disability rating is less than 100% under the VA rating schedule. To receive TDIU, the Veteran must show that because of his or her service-connected conditions, he or she is unable to secure or follow a substantially gainful occupation. The veteran must also meet certain requirements regarding his individual ratings. For more information, click here.
