2027 ICD-10-CM Diagnosis Code I47.21Torsades de pointes
ICD-10-CM Codes›I00–I99›I30-I5A›I47
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 238
- Not Chronic
I47.21 is a billable ICD-10-CM diagnosis code for torsades de pointes. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 308 through 310, 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 54 closely related codes. Coders also document this condition as torsade de pointes with short coupling interval syndrome. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Cardiac dysrhythmias.
For Medicare Advantage risk adjustment, I47.21 maps to CMS-HCC Category 238 (Specified Heart Arrhythmias) under the V28 model, adding a risk factor of about 0.299 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
I47.21 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Torsade de pointes with short coupling interval syndrome
- Torsades de pointe caused by drug
- Torsades de pointes
- Ventricular tachycardia, polymorphic
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to I47.21: its own notes plus those printed at I47 and Chapter 9. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
- systemic connective tissue disorders (M30-M36)
- transient cerebral ischemic attacks and related syndromes (G45.-)
Code First
The underlying condition named in the note is sequenced before this code.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
Code Also
A second code may be needed to fully describe the condition; the note gives no sequencing direction.
- if applicable, long QT syndrome (I45.81)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name I47.21, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming I47.21: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 1
These codes carry an Excludes2 note naming I47.21: its condition is not part of those codes, and both may be reported when the patient has both.
- R00 Abnormalities of heart beat
Code First 2
These codes say to code first a condition named in the note, and I47.21 is one of the conditions named.
Use Additional Code 1
These codes say to use an additional code from the note, and I47.21 is one of the codes named.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Torsades de pointes I47.21
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Torsades de Pointes
a malignant form of polymorphic ventricular tachycardia that is characterized by heart rate between 200 and 250 beats per minute, and qrs complexes with changing amplitude and twisting of the points. the term also describes the syndrome of tachycardia with prolonged ventricular repolarization, long qt intervals exceeding 500 milliseconds or bradycardia. torsades de pointes may be self-limited or may progress to ventricular fibrillation.
Patient EducationClinical
Arrhythmia
An arrhythmia is a problem with the rate or rhythm of your heartbeat. Your heart beats too quickly, too slowly, or with an irregular pattern. Changes in the electrical signals that control your heartbeat cause arrhythmias.
The full article covers:
- What is an arrhythmia?
- What causes an arrhythmia?
- What are the symptoms of an arrhythmia?
- How is an arrhythmia diagnosed?
- What are the treatments for an arrhythmia?
- Can arrhythmias be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Code History & ChangesHistory
Replacement I47.21 replaces the following previously assigned code(s):
- I47.2 - Ventricular tachycardia
Questions About I47.21Overview
What is the ICD-10 code for torsades de pointes?
The ICD-10-CM code for torsades de pointes is I47.21 (sometimes written as I4721). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is I47.21 (Ventricular tachycardia) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report torsades de pointes on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does I47.21 group to?
When torsades de pointes is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, 309, 310, 308, with relative weights from 0.5686 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.
Is I47.21 a CC or MCC?
CMS lists I47.21 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 54 closely related codes in its exclusion list.
Can I47.21 be reported with R00.0?
Not as a rule. The Excludes1 note at I47, which applies to I47.21, lists "tachycardia NOS (R00.0)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is I47.21?
I47.21 (torsades de pointes) maps to CMS-HCC Category 238 (Specified Heart Arrhythmias), commonly written as HCC 238, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 96 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.
Does I47.21 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, I47.21 adds a risk adjustment factor of about 0.299 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.245 to 0.407 depending on the payment segment). HCC 238 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 238 category page.
