K90 ICD-10-CM Code: Intestinal malabsorption

K90 is the ICD-10-CM diagnosis code for intestinal malabsorption. K90 sits in the ICD-10-CM chapter for diseases of the digestive system (k00-k95), within the section covering other diseases of the digestive system (k90-k95).

Header codes like K90 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 K90'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.