2027 ICD-10-CM Diagnosis Code R29.0Tetany

ICD-10-CM Codes›R00–R99›R25-R29›R29

ICD-10-CM R29.0
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

R29.0 is a billable ICD-10-CM diagnosis code for tetany. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 640 through 641, 791, 793. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 100 closely related codes. 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to R29.0: its own notes plus those printed at Chapter 18. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Carpopedal spasm

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

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

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 18 (R00-R99) Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified applies to 774 codes
  • abnormal findings on antenatal screening of mother (O28.-)
  • certain conditions originating in the perinatal period (P04-P96)
  • signs and symptoms classified in the body system chapters
  • signs and symptoms of breast (N63, N64.5)

Notes

General instructions on how these codes are used.

From Chapter 18 (R00-R99) Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified applies to 774 codes
  • This chapter includes symptoms, signs, abnormal results of clinical or other investigative procedures, and ill-defined conditions regarding which no diagnosis classifiable elsewhere is recorded.
  • Signs and symptoms that point rather definitely to a given diagnosis have been assigned to a category in other chapters of the classification. In general, categories in this chapter include the less well-defined conditions and symptoms that, without the necessary study of the case to establish a final diagnosis, point perhaps equally to two or more diseases or to two or more systems of the body. Practically all categories in the chapter could be designated 'not otherwise specified', 'unknown etiology' or 'transient'. The Alphabetical Index should be consulted to determine which symptoms and signs are to be allocated here and which to other chapters. The residual subcategories, numbered .8, are generally provided for other relevant symptoms that cannot be allocated elsewhere in the classification.
  • The conditions and signs or symptoms included in categories R00-R94 consist of:
  • (a) cases for which no more specific diagnosis can be made even after all the facts bearing on the case have been investigated;
  • (b) signs or symptoms existing at the time of initial encounter that proved to be transient and whose causes could not be determined;
  • (c) provisional diagnosis in a patient who failed to return for further investigation or care;
  • (d) cases referred elsewhere for investigation or treatment before the diagnosis was made;
  • (e) cases in which a more precise diagnosis was not available for any other reason;
  • (f) certain symptoms, for which supplementary information is provided, that represent important problems in medical care in their own right.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name R29.0, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming R29.0: they are not reported together with it, unless the two conditions are unrelated.

  • E20 Hypoparathyroidism
    tetany NOS (R29.0)

Excludes2 1

These codes carry an Excludes2 note naming R29.0: its condition is not part of those codes, and both may be reported when the patient has both.

  • R25.2 Cramp and spasm
    carpopedal spasm (R29.0)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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)

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About R29.0Overview

What is the ICD-10 code for tetany?

The ICD-10-CM code for tetany is R29.0 (sometimes written as R290). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

What MS-DRG does R29.0 group to?

When tetany is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, 641, 640, with relative weights from 0.7864 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.

Is R29.0 a CC or MCC?

CMS lists R29.0 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 100 closely related codes in its exclusion list.

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.