P08.21
Post-term newborn
P08.21 (also written P0821) is a billable ICD-10-CM diagnosis code for post-term newborn. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 4 codes in category P08 (Disorders of newborn related to long gestation and high birth weight). The Alphabetic Index lists it under 2 entries. Its coding notes include 5 Excludes2 entries.
Guidelines tip
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
Chapter 16 codes are never used on the maternal record, and chapter 15 codes are never used on the newborn record. Chapter 16 codes can be used for life if the condition persists.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (5 notes)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- tetanus neonatorum (A33)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Home Health Primary
Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Other clinical group.
Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026Includes
Further defines or gives examples of the content of the category.
- the listed conditions, without further specification, as causes of morbidity or additional care, in newborn
Also from chapter/block level (1 note)
- conditions that have their origin in the fetal or perinatal period (before birth through the first 28 days after birth) even if morbidity occurs later
Inclusion terms
Conditions classified to this code.
- Newborn with gestation period over 40 completed weeks to 42 completed weeks
Notes
- When both birth weight and gestational age of the newborn are available, priority of assignment should be given to birth weight
Also from chapter/block level (1 note)
- Codes from this chapter are for use on newborn records only, never on maternal records
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 2 entries