2027 ICD-10-CM Diagnosis Code I47.9Paroxysmal tachycardia, unspecified
ICD-10-CM Codes›I00–I99›I30-I5A›I47
- Billable — Valid for Submission
- Risk Adjusts — HCC 238
- Chronic Condition
I47.9 is a billable ICD-10-CM diagnosis code for paroxysmal tachycardia, unspecified. 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. Coders also document this condition as incisional tachycardia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Cardiac dysrhythmias.
For Medicare Advantage risk adjustment, I47.9 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.
This medical diagnosis code is frequently used in Cardiology medical specialties to designate conditions such abnormalities of heart rhythm.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
I47.9 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.
- Incisional tachycardia
- Paroxysmal tachycardia
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to I47.9: 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.
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.
- Bouveret (-Hoffman) syndrome
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.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name I47.9, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming I47.9: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 1
These codes carry an Excludes2 note naming I47.9: 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 I47.9 is one of the conditions named.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disease, diseased See Also: Syndrome;
Syndrome See Also: Disease;
Bouveret (-Hoffman) I47.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Tachycardia, Paroxysmal
abnormally rapid heartbeats with sudden onset and cessation.
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.
Convert I47.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About I47.9Overview
What is the ICD-10 code for paroxysmal tachycardia, unspecified?
The ICD-10-CM code for paroxysmal tachycardia, unspecified is I47.9 (sometimes written as I479). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is I47.9 (Paroxysmal tachycardia) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report paroxysmal tachycardia, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does I47.9 group to?
When paroxysmal tachycardia, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 309, 310, 308, with relative weights from 0.5686 to 1.1809 depending on complications. Higher weights mean higher Medicare reimbursement.
Can I47.9 be reported with R00.0?
Not as a rule. The Excludes1 note at I47, which applies to I47.9, 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 is coded first with I47.9?
The Code First note at I47, which applies to I47.9, reads: tachycardia complicating: abortion or ectopic or molar pregnancy (O00-O07, O08.8); obstetric surgery and procedures (O75.4). When one of these applies, it is sequenced before I47.9.
What HCC is I47.9?
I47.9 (paroxysmal tachycardia, unspecified) 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. In the Part D prescription drug model it maps to RxHCC 193.
Does I47.9 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, I47.9 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.
