P05.0
Non-Billable (Header)Newborn light for gestational age
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
What This Code Means
P05.0 is the ICD-10-CM diagnosis code for newborn light for gestational age. P05.0 sits in the ICD-10-CM chapter for certain conditions originating in the perinatal period (p00-p96), within the section covering disorders of newborn related to length of gestation and fetal growth (p05-p08).
Header codes like P05.0 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 P05.0'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.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for P05.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.