ICD-10-CM 2027
ICD-10 code for hypomagnesemia
From the official ICD-10-CM alphabetic index entry “Hypomagnesemia”. Page updated September 29, 2026.
About coding hypomagnesemia
The ICD-10-CM code for hypomagnesemia is E83.42 (Hypomagnesemia). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on E83.42.
Within E83.4 (disorders of magnesium metabolism), E83.42 is specifically for hypomagnesemia. Related codes cover unspecified (E83.40), Hypermagnesemia (E83.41) and other disorders of magnesium metabolism (E83.49).
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 640 (Miscellaneous Disorders of Nutrition, Metabolism, Fluids and Electrolytes with MCC, relative weight 1.3395) and DRG 641 (Miscellaneous Disorders of Nutrition, Metabolism, Fluids and Electrolytes without MCC, relative weight 0.7865), in MDC 10 (Endocrine, Nutritional and Metabolic Diseases and Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific hypomagnesemia codes (official index)
- neonatal P71.2 — Neonatal hypomagnesemia
Common questions about hypomagnesemia ICD-10 codes
What is the ICD-10 code for hypomagnesemia?
- E83.42 — Hypomagnesemia. More specific codes apply when the documentation supports them: P71.2.
What is the ICD-10 code for neonatal hypomagnesemia?
- P71.2 — Neonatal hypomagnesemia.
Is E83.42 billable?
- Yes. E83.42 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can E83.42 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict E83.42 as a principal diagnosis.
Is E83.42 a CC or MCC?
- No. E83.42 is neither a CC nor an MCC under MS-DRG v44.0.