ICD10BillableValid for clinical use

ICD-10 Code P08.21: Post-term newborn

P08.21 is a billable ICD-10 diagnosis code used to classify Post-term newborn in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Certain conditions originating in the perinatal period (P00-P96).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Certain conditions originating in the perinatal period (P00-P96).

When is it used?

  • May be used when a clinician documents post-term newborn in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
16Certain conditions originating in the perinatal period (P00-P96)
block
P05-P08Disorders of newborn related to length of gestation and fetal growth
category
P08Disorders of newborn related to long gestation and high birth weight
category
P08.2Late newborn, not heavy for gestational age
currentP08.2

Official coding notes

Inclusion terms
  • Newborn with gestation period over 40 completed weeks to 42 completed weeks

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

PediatricianNeonatologist

Coding guidelines

Common synonyms

Post-term newborn

Frequently asked questions

Code details

CodeP08.21
SystemICD10
Display namePost-term newborn
ChapterCertain conditions originating in the perinatal period (P00-P96)
BlockDisorders of newborn related to length of gestation and fetal growth

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Newborn(infant) (liveborn) (singleton)Post-term(40-42 weeks) (pregnancy) (mother)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code P08.21 for Post-term newborn | HealthAssure