2026 ICD-10-CM Diagnosis Code E20.9Hypoparathyroidism, unspecified

ICD-10-CM Codes›E00–E89›E20-E35›E20

ICD-10-CM E20.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E20.9 is a billable ICD-10-CM diagnosis code for hypoparathyroidism, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 643 through 645. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified endocrine disorders.

Code Identity

ICD-10-CM Code
E20.9
Billable Status
Yes — Valid for Submission
Code Describes
Hypoparathyroidism, unspecified
Short Description
Hypoparathyroidism, unspecified
Same as the full description in the CMS dataset.
Parent Code
E20
Hypoparathyroidism

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE20-E35Disorders of other endocrine glands
CategoryE20Hypoparathyroidism
This CodeE20.9Hypoparathyroidism, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • 10p partial monosomy syndrome
  • Cataract in hypoparathyroidism
  • Cataract in systemic disorders
  • Chorea due to endocrine disorder
  • Chorea due to hypoparathyroidism
  • Deletion of part of chromosome 10
  • Endocrine myopathy
  • Hypocalcemic tetany
  • Hypoparathyroidism
  • Hypoparathyroidism due to granulomatous disease
  • Hypoparathyroidism due to hemochromatosis
  • Hypoparathyroidism due to impaired PTH secretion
  • Hypoparathyroidism, deafness, renal disease syndrome
  • Myopathy in hypoparathyroidism
  • Parathyroid hypocalcemic tetany
  • Tetany

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Parathyroid 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.

    • Cataract(cortical) (immature) (incipient)
      • in (due to)
        • hypoparathyroidism
    • Deficiency, deficient
      • parathyroid (gland)
    • Hypoparathyroidism
    • Insufficiency, insufficient
      • parathyroid (gland)
    • Myopathy
      • in (due to)
        • hypoparathyroidism
    • Parathyroid tetany
    • Tetany(due to)
      • parathyroid (gland)

Clinical ClassificationClinical

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

CCSR END015
Other specified and unspecified endocrine disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Hypoparathyroidism

    a condition caused by a deficiency of parathyroid hormone (or pth). it is characterized by hypocalcemia and hyperphosphatemia. hypocalcemia leads to tetany. the acquired form is due to removal or injuries to the parathyroid glands. the congenital form is due to mutations of genes, such as tbx1; (see digeorge syndrome); casr encoding calcium-sensing receptor; or pth encoding parathyroid hormone.

  • 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)

  • Acquired Hypoparathyroidism

    hypoparathyroidism, the cause of which is not present at birth.

  • Albright Hereditary Osteodystrophy with Multiple Hormone Resistance|PHP1a|Pseudohypoparathyroidism Type 1a

    parathyroid hormone (pth) resistance caused by heterozygous inactivating mutation(s) of the maternal allele of the gnas gene encoding gs-alpha, resulting in expression of pth from only the paternal allele. clinical manifestations include albright hereditary osteodystrophy, early-onset obesity, and, in some cases, resistance to thyroid-stimulating hormone, gonadotropins, and growth hormone-releasing hormone, reflecting additional manifestations of gs-alpha deficiency.

  • Albright Hereditary Osteodystrophy without Multiple Hormone Resistance|Albright Hereditary Osteodystrophy with Multiple Hormone Resistance|PPHP|Pseudopseudohypoparathyroidism

    a condition caused by inactivating mutation(s) in the paternal allele of the gnas gene, encoding gs-alpha, resulting in expression of the gs-alpha protein from only the maternal allele. affected individuals have the clinical phenotype of albright hereditary osteodystrophy without hormone resistance.

  • Albright's Hereditary Osteodystrophy|Albright Hereditary Osteodystrophy|Albright's Hereditary Osteodystrophy with Multiple Hormone Resistance|PHP1A|Pseudohypoparathyroidism, Type IA

    a rare, autosomal dominant syndrome caused by mutations in the gnas gene. it is characterized by the presence of short stature, obesity, round face, brachydactyly, subcutaneous ossifications, and pseudohypoparathtyroidism.

  • Autosomal Dominant Hypoparathyroidism

    hypoparathyroidism associated with heterozygous mutation(s) in the pth gene, which encodes parathyroid hormone, or in the gcm2 gene, which encodes chorion-specific transcription factor gcmb.

  • Autosomal Recessive Hypoparathyroidism

    hypoparathyroidism associated with homozygous mutation(s) in the pth gene, which encodes parathyroid hormone, or in the gcm2 gene, which encodes chorion-specific transcription factor gcmb.

  • Barakat Syndrome|Hypoparathyroidism, Deafness, and Renal Anomalies Syndrome

    a condition characterized by hypoparathyroidism, sensorineural deafness, and renal failure. it is related to autosomal dominant inactivating mutation(s) in gata3, encoding a transcription factor important for the embryonic development of the parathyroid gland, the auditory stem, and the kidneys.

  • Grade 1 Hypoparathyroidism, CTCAE|Grade 1 Hypoparathyroidism

    asymptomatic; clinical or diagnostic observations only; intervention not indicated

  • Grade 2 Hypoparathyroidism, CTCAE|Grade 2 Hypoparathyroidism

    moderate symptoms; medical intervention indicated

  • Grade 3 Hypoparathyroidism, CTCAE|Grade 3 Hypoparathyroidism

    severe symptoms; medical intervention or hospitalization indicated

  • Grade 4 Hypoparathyroidism, CTCAE|Grade 4 Hypoparathyroidism

    life-threatening consequences; urgent intervention indicated

  • Grade 5 Hypoparathyroidism, CTCAE|Grade 5 Hypoparathyroidism

    death

  • Hypoparathyroidism

    an endocrine disorder characterized by decreased production of parathyroid hormone by the parathyroid glands. it is usually caused by damage of the parathyroid glands during head and neck surgery. signs and symptoms include muscle cramps, abdominal pain, dry skin, brittle nails, cataracts, tetany, and convulsions.

  • Hypoparathyroidism, CTCAE|Hypoparathyroidism|Hypoparathyroidism

    a disorder characterized by a decrease in production of parathyroid hormone by the parathyroid glands.

  • Hypoparathyroidism-Retardation-Dysmorphism Syndrome|HRDS|Hypoparathyroidism with Short Stature, Mental Retardation, and Seizures|Hypoparathyroidism, Congenital, Associated with Dysmorphism, Growth Retardation, and Developmental Delay|Sanjad-Sakati Syndrome

    an autosomal recessive condition caused by mutation(s) in the tbce gene, encoding tubulin-specific chaperone e. it is characterized by congenital hypoparathyroidism, mental retardation, seizures and developmental delay.

  • Iatrogenic Hypoparathyroidism

    hypoparathyroidism resulting from medical treatment or intervention.

  • Parathyroid Hormone Resistance|Pseudohypoparathyroidism|Pseudoparathyroidism

    a finding indicating decreased tissue sensitivity to parathyroid hormone.

  • Primary Hypoparathyroidism

    abnormally low levels of parathyroid hormone due to a disorder originating within the parathyroid glands.

  • Pseudohypoparathyroidism

    a condition characterized by the insensitivity of the tissues to respond to the activity of the parathyroid hormone. it results in increased levels of parathyroid hormone in the serum, hypocalcemia, and hyperphosphatemia.

  • Renal Parathyroid Hormone Resistance|Pseudohypoparathyroidism Type 1b

    parathyroid hormone resistance caused by defects in methylation in the gnas gene that cause loss of expression of gs-alpha from the maternal allele in renal tissue, resulting in decreased phosphate excretion and increased calcium excretion. individuals with this condition may also have brachydactyly and partial resistance to thyroid-stimulating hormone.

  • Secondary Parathyroid Hormone Resistance|Acquired Parathyroid Hormone Resistance|Acquired Parathyroid Hormone Resistance|Pseudohypoparathyroidism, Type 2|Pseudohypoparathyroidism, Type 2

    parathyroid hormone (pth) resistance caused by vitamin d deficiency and characterized by clinically increased pth concentrations with relative hyperphosphatemia. the diagnosis can be confirmed by finding of a normal cyclic adenosine monophosphate (camp) response to pth infusion, but deficient phosphaturic response, indicating a defect distal to camp generation in renal cells.

  • TBCE wt Allele|HRD|Hypoparathyroidism, Growth and Mental Retardation, and Dysmorphism Gene|KCS|KCS1|Kenny-Caffey Syndrome Gene|PEAMO|Tubulin Folding Cofactor E wt Allele|pac2

    human tbce wild-type allele is located in the vicinity of 1q42.3 and is approximately 85 kb in length. this allele, which encodes tubulin-specific chaperone e protein, is involved in both tubulin folding and tubulin dimer dissociation. mutations in the gene are associated with progressive encephalopathy with amyotrophy and optic atrophy, hypoparathyroidism-retardation-dysmorphism syndrome and kenny-caffey syndrome 1.

  • Transient Neonatal Hypoparathyroidism

    a disorder of decreased production of parathyroid hormone by the parathyroid gland in a newborn. it is due to maternal hyperparathyroidism. it may be characterized by hypocalcemic seizures in the first weeks of life.

  • X-Linked Hypoparathyroidism|X-linked Hypoparathyroidism

    hypoparathyroidism in which the inheritance is recessive and linked to the q26-q27 region of the x chromosome. the parathyroid glands are usually incompletely developed (parathyroid dysgenesis) or absent (parathyroid agenesis).

  • Tetany

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

Patient EducationClinical

Parathyroid Disorders

Most people have four pea-sized glands, called parathyroid glands, on the thyroid gland in the neck. Though their names are similar, the thyroid and parathyroid glands are completely different. The parathyroid glands make parathyroid hormone (PTH), which helps your body keep the right balance of calcium and phosphorous.

Read the full article at MedlinePlus

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

Convert E20.9 to ICD-9-CMHistory

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

ICD-9-CM
252.1 Hypoparathyroidism
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 E20.9Overview

Is E20.9 (Hypoparathyroidism) a billable code?

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

What MS-DRG does E20.9 group to?

When hypoparathyroidism, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 643, 644, 645, with relative weights from 0.7683 to 1.6461 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of E20.9?

Under the General Equivalence Mappings, hypoparathyroidism, unspecified converts to ICD-9-CM 252.1 (hypoparathyroidism). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.