ICD-10 P74.421
Billable / SpecificHyperchloremia of newborn
About ICD-10-CM P74.421
ICD-10-CM code P74.421 represents Hyperchloremia of newborn. This is a billable/specific code in the Perinatal Period chapter (block P74). The 2026 edition of ICD-10-CM P74.421 became effective on October 1, 2025.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under P74.421. Per CMS ICD-10-CM Tabular 2026.
- Hyperchloremic metabolic acidosis
Type 2 Excludes
Not included here, the excluded code is not part of P74.421, but a patient may have both conditions at the same time. Both codes may be coded together when applicable.
- late metabolic acidosis of the newborn (P74.0)
Medicare LCD Coverage for P74.421
Local Coverage Determinations (LCDs) from CMS MACs that list P74.421 as a covered diagnosis.
This doesn't mean the code isn't covered, it means no MAC has issued a Local Coverage Determination naming this specific code. Coverage may still apply under National Coverage Determinations or general medical-necessity rules.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing P74.421.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but P74.421 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with P74.421
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Codes Adjacent To P74.421
Other codes in section P70-P74 (Transitory endocrine and metabolic disorders specific to newborn).
ICD-10 P74.421, Billing FAQ
Is ICD-10 code P74.421 billable? +
Yes, P74.421 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to P74.421? +
ICD-10 P74.421 includes: Hyperchloremic metabolic acidosis.
What codes are Type 2 Excludes for P74.421? +
Type 2 Excludes (may be coded together when both conditions exist): late metabolic acidosis of the newborn (P74.0)
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on June 1, 2026.
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