ICD-10-CM 2027
ICD-10 code for hypernatremia newborn
From the official ICD-10-CM alphabetic index entry “Newborn (infant) (liveborn) (singleton) › hypernatremia”. Page updated September 29, 2026.
About coding hypernatremia newborn
The ICD-10-CM code for hypernatremia newborn is P74.21 (Hypernatremia of newborn).
Within P74.2 (disturbances of sodium balance of newborn), P74.21 is specifically for hypernatremia of newborn. Related codes cover hyponatremia of newborn (P74.22).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 791 (Prematurity with Major Problems, relative weight 4.1075) and DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), in MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about hypernatremia newborn ICD-10 codes
What is the ICD-10 code for hypernatremia newborn?
- P74.21 — Hypernatremia of newborn.
Is P74.21 billable?
- Yes. P74.21 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can P74.21 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict P74.21 as a principal diagnosis.
Is P74.21 a CC or MCC?
- No. P74.21 is neither a CC nor an MCC under MS-DRG v44.0.