2026 ICD-10-CM Diagnosis Code E83.42Hypomagnesemia

ICD-10-CM Codes›E00–E89›E70-E88›E83

ICD-10-CM E83.42
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E83.42 is a billable ICD-10-CM diagnosis code for hypomagnesemia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 640 through 641. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified nutritional and metabolic disorders.

Code Identity

ICD-10-CM Code
E83.42
Billable Status
Yes — Valid for Submission
Code Describes
Hypomagnesemia
Short Description
Hypomagnesemia
Same as the full description in the CMS dataset.
Parent Code
E83.4
Disorders of magnesium metabolism

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE70-E88Metabolic disorders
CategoryE83Disorders of mineral metabolism
This CodeE83.42Hypomagnesemia

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Autosomal dominant primary hypomagnesemia with hypocalciuria
  • Blood magnesium below reference range
  • Blood magnesium outside reference range
  • Drug-induced hypomagnesemia
  • EGF-related primary hypomagnesemia with intellectual disability
  • Familial hypomagnesemia hypercalciuria nephrocalcinosis with severe ocular involvement
  • Familial hypomagnesemia-hypercalciuria
  • Familial primary hypomagnesemia with hypercalciuria and nephrocalcinosis
  • Familial primary hypomagnesemia with hypercalciuria and nephrocalcinosis without severe ocular involvement
  • Familial primary hypomagnesemia with normocalciuria
  • Familial primary hypomagnesemia with normocalciuria and normocalcemia
  • Hypocalcemic tetany
  • Hypocalciuria
  • Hypomagnesemia
  • Hypomagnesemia co-occurrent with normocalciuria
  • Hypomagnesemia with secondary hypocalcemia
  • Isolated autosomal dominant hypomagnesemia Glaudemans type
  • Isolated familial intestinal hypomagnesemia
  • Isolated familial renal hypomagnesemia
  • Parathyroid hypocalcemic tetany
  • Primary hypomagnesemia
  • Primary hypomagnesemia, generalized seizures, intellectual disability, obesity syndrome
  • Primary hypomagnesemia, refractory seizures, intellectual disability syndrome
  • Secondary hypomagnesemia
  • Tetany

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Disorder(of)
      • metabolism NOS
        • magnesium
          • hypomagnesemia
    • Hypomagnesemia

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR END016
Other specified and unspecified nutritional and metabolic disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Tetany

    a disorder characterized by muscle twitches, cramps, and carpopedal spasm, and when severe, laryngospasm and seizures. this condition is associated with unstable depolarization of axonal membranes, primarily in the peripheral nervous system. tetany usually results from hypocalcemia or reduced serum levels of magnesium that may be associated with hyperventilation; hypoparathyroidism; rickets; uremia; or other conditions. (from adams et al., principles of neurology, 6th ed, p1490)

  • Grade 1 Hypomagnesemia, CTCAE|Grade 1 Hypomagnesemia

  • Grade 2 Hypomagnesemia, CTCAE|Grade 2 Hypomagnesemia

    <1.2 - 0.9 mg/dl; <0.5 - 0.4 mmol/l

  • Grade 3 Hypomagnesemia, CTCAE|Grade 3 Hypomagnesemia

    <0.9 - 0.7 mg/dl; <0.4 - 0.3 mmol/l

  • Familial Primary Hypomagnesemia

    a hereditary disorder that leads to a selective defect in renal or intestinal magnesium absorption, resulting in a low serum magnesium concentration.

  • Grade 1 Hypomagnesemia, CTCAE|Grade 1 Hypomagnesemia

  • Grade 2 Hypomagnesemia, CTCAE|Grade 2 Hypomagnesemia

    <1.2-0.9 mg/dl; <0.5-0.4 mmol/l

  • Grade 3 Hypomagnesemia, CTCAE|Grade 3 Hypomagnesemia

    <0.9-0.7 mg/dl; <0.4-0.3 mmol/l

  • Grade 4 Hypomagnesemia, CTCAE|Grade 4 Hypomagnesemia

    <0.7 mg/dl; <0.3 mmol/l; life-threatening consequences

  • Grade 5 Hypomagnesemia, CTCAE|Grade 5 Hypomagnesemia

    death

  • Hypomagnesemia

    lower than normal levels of magnesium in the circulating blood.

  • Hypomagnesemia, CTCAE|Hypomagnesemia|Hypomagnesemia

    a disorder characterized by laboratory test results that indicate a low concentration of magnesium in the blood.

  • TRPM6 wt Allele|CHAK2|FLJ22628|HMGX|HOMG|HOMG1|HSH|Hypomagnesemia, Secondary Hypocalcemia Gene|Transient Receptor Potential Cation Channel Subfamily M Member 6 wt Allele|Transient Receptor Potential Cation Channel, Subfamily M, Member 6 Gene

    human trpm6 wild-type allele is located in the vicinity of 9q21.13 and is approximately 166 kb in length. this allele, which encodes transient receptor potential cation channel subfamily m member 6 protein, is involved in both magnesium homeostasis and protein phosphorylation. mutation of the gene is associated with hypomagnesemia.

  • Tetany

    sudden and involuntary contraction of a muscle of group of muscles due to hypocalcemia.

  • Nephrocalcinosis

    deposition of calcium in the renal parenchyma, resulting from high levels of calcium in the blood and/or urine.

Patient EducationClinical

Metabolic Disorders

Metabolism is the process your body uses to get or make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system break the food parts down into sugars and acids, your body's fuel.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert E83.42 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
275.2 Dis magnesium metabolism
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About E83.42Overview

Is E83.42 (Disorders of magnesium metabolism) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report hypomagnesemia on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E83.42 group to?

When hypomagnesemia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 640, 641, with relative weights from 0.7782 to 1.3356 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of E83.42?

Under the General Equivalence Mappings, hypomagnesemia converts to ICD-9-CM 275.2 (dis magnesium metabolism). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.