P23 ICD-10-CM Code: Congenital pneumonia

P23 is the ICD-10-CM diagnosis code for congenital pneumonia. P23 sits in the ICD-10-CM chapter for certain conditions originating in the perinatal period (p00-p96), within the section covering respiratory and cardiovascular disorders specific to the perinatal period (p19-p29).

Header codes like P23 cannot be reported on claims directly, they organize child codes that share clinical context but the actual diagnosis must be coded to the highest level of specificity supported by the documentation. Coders should look at P23's child codes and select the one that matches the patient's documented presentation, since payers reject header codes submitted as the primary diagnosis. For risk adjustment workflows, header codes never contribute to a Medicare Advantage member's RAF score on their own; only billable child codes that happen to map to a payment HCC affect risk-adjusted plan payments.