Claim Raven explanation
What this means
For a disability aggravated by service, the rating generally reflects the increase beyond the degree that existed when service began. The preservice degree must be expressed in terms of the rating schedule when it can be determined.
The rule includes exceptions: no deduction is made when the present disability is total, or when the preservice degree cannot be determined under the schedule. This is about calculating the rating after aggravation is established.
How this helps your claim
It helps explain a deduction on a rating sheet. Check the evidence for the starting degree, the current degree, and the reasoning for any subtraction rather than assuming the presence of a preservice condition fixes the amount.
What to check in your records
Use your decision, examination reports, and relevant records to check the following points.
- Find entrance and preservice records showing the original level of disability.
- Check the current findings and the diagnostic criteria used for both levels.
- Look for the stated deduction and the explanation of how VA determined it.
Read the deduction as a separate rating calculation
Once aggravation is established, the decision may need to identify a preservice degree and subtract it from the current evaluation. That earlier degree must be ascertainable in schedule terms. A diagnosis before service does not necessarily provide a percentage.
Compare the entrance findings with the criteria and calculation used. If the decision applies a deduction, locate the evidence supporting that specific level. The regulation's exceptions should be considered as written, including its treatment of an unascertainable preservice degree and a present total disability.
Is this calculation the same as denying service connection?
No. It concerns how the compensable degree is calculated for a disability aggravated by service. The underlying recognition and the amount evaluated are separate matters. Identify whether your question concerns the aggravation finding, the preservice level or the subtraction itself.
Official regulatory text
38 CFR § 4.22
eCFR snapshot: September 3, 2026. Layout and spacing are adapted for reading. The full section and its tables are included below.
§ 4.22 Rating of disabilities aggravated by active service.
In cases involving aggravation by active service, the rating will reflect only the degree of disability over and above the degree existing at the time of entrance into the active service, whether the particular condition was noted at the time of entrance into the active service, or it is determined upon the evidence of record to have existed at that time. It is necessary therefore, in all cases of this character to deduct from the present degree of disability the degree, if ascertainable, of the disability existing at the time of entrance into active service, in terms of the rating schedule, except that if the disability is total (100 percent) no deduction will be made. The resulting difference will be recorded on the rating sheet. If the degree of disability at the time of entrance into the service is not ascertainable in terms of the schedule, no deduction will be made.
Related references
- 38 CFR § 4.1: What a VA disability rating measures
- 38 CFR § 3.159: VA duty to assist: records and examinations
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