Muscle Group XXI Injury — VA Rating (DC 5321)

The VA rates Group XXI.Respiration.Thoracic muscle group Function: Muscles of respiration under Diagnostic Code 5321 at 0%, 10%, 20%. The minimum 0% rating requires: Slight. The maximum 20% rating requires: Severe or Moderately Severe.

The VA rates Group XXI.Respiration.Thoracic muscle group Function: Muscles of respiration under Diagnostic Code (DC) 5321, governed by 38 CFR 38 CFR § 4.73. The diagnostic code establishes the specific rating tiers and severity criteria the VA examiner applies.

A 0% rating requires: Slight. A 20% rating requires: Severe or Moderately Severe. The difference typically reflects the frequency, severity, or functional impact of the condition as documented in medical records and C&P examination findings.

Group XXI.Respiration.Thoracic muscle group Function: Muscles of respiration maxes at 20%, well below the single-disability TDIU threshold. However, combined with other service-connected disabilities, TDIU may be achievable under 38 CFR § 4.16. Focus on establishing secondary conditions to increase the combined rating.

The key evidence for Group XXI.Respiration.Thoracic muscle group Function: Muscles of respiration is documentation of how the condition affects daily functioning. For musculoskeletal conditions, range of motion measurements (active, passive, weight-bearing, and non-weight-bearing per Correia v. McDonald) and flare-up documentation are critical. A nexus letter from a qualified medical professional linking the current severity to service is essential for contested claims.

The C&P examiner uses a Musculoskeletal System DBQ and evaluates your condition against the DC 5321 rating criteria. Expect range of motion testing in multiple positions. Under Correia v. McDonald, the examiner must test active, passive, weight-bearing, and non-weight-bearing range of motion. Report your worst flare-up symptoms — if you cannot attend during a flare, request the exam be rescheduled.