2026 ICD-10-CM Diagnosis Code R29.0Tetany

ICD-10-CM Codes›R00–R99›R25-R29›R29

ICD-10-CM R29.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R29.0 is a billable ICD-10-CM diagnosis code for tetany. 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. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. Coders also document this condition as carpopedal spasm. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nervous system signs and symptoms.

Code Identity

ICD-10-CM Code
R29.0
Billable Status
Yes — Valid for Submission
Code Describes
Tetany
Short Description
Tetany
Same as the full description in the CMS dataset.
Parent Code
R29
Other symptoms and signs involving the nervous and musculoskeletal systems

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR25-R29Symptoms and signs involving the nervous and musculoskeletal systems
CategoryR29Other symptoms and signs involving the nervous and musculoskeletal systems
This CodeR29.0Tetany

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carpopedal spasm
  • Chvostek sign
  • Hypocalcemic tetany
  • Hypomagnesemic tetany
  • Named sign of skeletal muscle
  • Tetany
  • Trousseau sign

Tabular List NotesGuidance

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

Inclusion Terms

  • Carpopedal spasm

Type 1 Excludes

  • hysterical tetany F44.5
  • neonatal tetany P71.3
  • parathyroid tetany E20.9
  • post-thyroidectomy tetany E89.2

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.

    • Diathesis
      • spasmophilic
    • Pseudotetany
    • Syndrome
      • magnesium-deficiency
    • Tetany(due to)
    • Tetany(due to)
      • convulsions
    • Tetany(due to)
      • hyperkinetic
    • Tetany(due to)
      • pseudotetany

Clinical ClassificationClinical

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

CCSR SYM010
Nervous system signs and symptoms
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)

  • Tetany

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

Patient EducationClinical

Muscle Cramps

Muscle cramps are sudden, involuntary contractions or spasms in one or more of your muscles. They are very common and often occur after exercise. Some people get muscle cramps, especially leg cramps, at night. They can be painful, and they may last a few seconds to several minutes.

The full article covers:

  • What are muscle cramps?
  • What causes muscle cramps?
  • Who is at risk for muscle cramps?
  • When do I need to see a health care provider for muscle cramps?
  • What are the treatments for muscle cramps?
  • Can muscle cramps be prevented?

Read the full article at MedlinePlus

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

Convert R29.0 to ICD-9-CMHistory

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

ICD-9-CM
781.7 Tetany
Exact Match The mapping is direct, with no qualifiers.

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 R29.0Overview

Is R29.0 a billable code?

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

What MS-DRG does R29.0 group to?

When tetany 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.

Can R29.0 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the tetany is established, that condition takes the principal position instead.

What is the ICD-9 equivalent of R29.0?

Under the General Equivalence Mappings, tetany converts to ICD-9-CM 781.7 (tetany). The mapping is a direct match.

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.