S21.459A ICD-10-CM Code: Open bite of unspecified back wall of thorax with penetration into thoracic cavity, initial encounter

S21.459A is the ICD-10-CM diagnosis code for open bite of unspecified back wall of thorax with penetration into thoracic cavity, initial encounter. S21.459A sits in the ICD-10-CM chapter for injury, poisoning and certain other consequences of external causes (s00-t88), within the section covering injuries to the thorax (s20-s29).

S21.459A is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

S21.459A is a billable ICD-10-CM code that can be reported on claims but does not currently contribute to a Medicare Advantage member's RAF score under any CMS risk adjustment model (V28, V24, ESRD, or RxHCC). Coders reviewing S21.459A should check whether additional documentation would support a more specific child code in the same hierarchy that does map to a payment HCC, capturing the correct specificity is the highest-impact RAF improvement available within accurate coding.