Crystal's Coder Hub🫀 ICD-10 CM I48.19 — Other Persistent Atrial Flutter
Billable Code Confirmed
[ICD-10-CM] I48.19 is a valid, billable 5-character ICD-10-CM code for FY2026. Characters 1-3 (
I48) define the category (atrial fibrillation and flutter); character 4 (.1) narrows to the persistent flutter subcategory; character 5 (.19) specifies “other” persistent atrial flutter, capturing flutter that is persistent in duration but not classifiable as the longstanding persistent subtype. No additional characters are required or available.
Non-Billable Parent Codes — Never Submit These
- ❌
I48— 3-character header — does not specify flutter vs. fibrillation, or duration- ❌
I48.1— 4-character header — specifies persistent flutter but lacks the required 5th character specifying typeAlways submit I48.19 (all 5 characters) when persistent atrial flutter is documented and the clinical record does not support longstanding persistent classification (>12 months duration).
Clinical Context: Persistent vs. Longstanding Persistent vs. Paroxysmal
ICD-10 CM I48.19 captures atrial flutter that has been continuously present for more than 7 days (or required cardioversion to terminate) but has not yet reached the 12-month threshold for longstanding persistent classification (I48.11). The “other” qualifier also encompasses atypical (type II) flutter — including non-isthmus-dependent circuits — that is persistent in duration. Documentation of duration and, when available, flutter type from the electrophysiology study or cardiology notes drives this distinction.
Code Classification
ICD-10 CM Diagnosis Code — wRVU, assistant-payable status, and global period fields are not applicable to ICD-10 CM diagnosis codes. For procedural coding associated with this diagnosis, refer to the CPT Procedural Crosswalk and ICD-10-PCS Crosswalk sections below.
🔍 Code Description
ICD-10 CM I48.19 classifies other persistent atrial flutter — a supraventricular tachyarrhythmia characterized by rapid, regular atrial electrical activity (typically 250-350 bpm) with organized reentrant circuits that has persisted continuously for more than 7 days, where the clinical documentation does not support classification as typical (type I) flutter or longstanding persistent flutter (>12 months).1,2
Atrial flutter arises from a macro-reentrant circuit within the atrium. The “other” persistent designation most commonly reflects atypical (type II) flutter, which involves circuits outside the cavotricuspid isthmus — including circuits around pulmonary veins, mitral annulus, or surgical scars — and is not amenable to standard isthmus-dependent ablation. Persistent duration implies the arrhythmia has not self-terminated and typically requires pharmacologic or electrical cardioversion for rhythm control.2,3
🌳 Code Tree / Hierarchy
I48 Atrial fibrillation and flutter ❌ Non-billable
│
├── I48.0 Paroxysmal atrial flutter ✅ Billable
│
├── I48.1 Persistent atrial flutter ❌ Non-billable (4-char header)
│ │
│ ├── I48.11 Longstanding persistent atrial flutter ✅ Billable
│ └── I48.19 Other persistent atrial flutter ◀ THIS CODE ✅ Billable
│
├── I48.2 Chronic atrial fibrillation ❌ Non-billable
│ │
│ ├── I48.20 Chronic atrial fibrillation, unspecified ✅ Billable
│ ├── I48.21 Permanent atrial fibrillation ✅ Billable
│ └── I48.19 [see above — different branch]
│
├── I48.3 Typical atrial flutter ✅ Billable
├── I48.4 Atypical atrial flutter ✅ Billable
└── I48.9 Unspecified atrial fibrillation and flutter ✅ Billable
Duration Documentation Is the Coding Pivot
For inpatient admissions, the cardiology or electrophysiology note should document how long the flutter has been present. If duration exceeds 12 months, upgrade to I48.11 (longstanding persistent). If duration is 7 days or less and self-terminated, consider I48.0 (paroxysmal). When duration is ambiguous, a CDI query is appropriate before defaulting to I48.19.
✅ Includes
The following clinical terms and scenarios map to I48.19 when documented:
- Persistent atrial flutter, atypical (type II)
- Persistent atrial flutter, non-isthmus-dependent
- Persistent atrial flutter, not otherwise specified (when >7 days, <12 months)
- Clockwise or counterclockwise flutter of non-typical circuit, persistent duration
- Persistent flutter identified on EP study as non-type I, duration <12 months
❌ Excludes
Excludes 1 — Cannot Be Coded Simultaneously with I48.19
| Code | Description | Note |
|---|---|---|
| I48.0 | Paroxysmal atrial flutter | Paroxysmal episodes self-terminate within 7 days — mutually exclusive by definition with persistent duration; use only one based on documented episode type |
| I48.11 | Longstanding persistent atrial flutter | Duration >12 months distinguishes longstanding from I48.19; do not code both — the more specific duration code applies |
Excludes 1 Violation Risk
The most common error is coding both I48.11 and I48.19 when a patient has had flutter for “over a year.” Once duration exceeds 12 months and is documented, I48.11 is the correct code — I48.19 cannot be assigned simultaneously. Query the cardiologist for documented duration when the record is ambiguous.
Excludes 2 — May Be Coded in Addition if Separately Present
| Code | Description | Note |
|---|---|---|
| I48.3 | Typical atrial flutter (type I) | If EP study documents concurrent type I and type II flutter circuits, both may be coded if separately documented and clinically distinct |
| I48.91 | Unspecified atrial fibrillation | Atrial fibrillation and atrial flutter may coexist; code both when documented by the provider as simultaneously present |
📋 Clinical Overview
Flutter Duration and Type Classification
Accurate code selection within the I48.1x subcategory depends on two axes: duration (paroxysmal vs. persistent vs. longstanding persistent) and flutter circuit type (typical/isthmus-dependent vs. atypical/non-isthmus-dependent). I48.19 captures the intersection of persistent duration and non-classifiable or atypical type.2,3
| Feature | I48.0 — Paroxysmal | I48.19 — Other Persistent | I48.11 — Longstanding Persistent |
|---|---|---|---|
| Duration | Self-terminates ≤7 days | >7 days, <12 months (or cardioverted) | Continuous >12 months |
| Cardioversion Required? | Usually no | Often yes | Usually attempted; may fail |
| Flutter Type | Any | Atypical (type II) or unspecified persistent | Any |
| Ablation Target | Cavotricuspid isthmus (if type I) | Non-isthmus circuit; complex ablation | Variable; may not be attempted |
| Anticoagulation | May qualify; CHA₂DS₂-VASc-driven | Typically required | Required |
| DRG Impact (Secondary Dx) | CC | CC | CC |
CDI Query Trigger — Duration Not Documented
When the admission H&P references atrial flutter and the ECG confirms it, but the cardiology note does not document onset date or duration, initiate a CDI query: “Can you clarify the duration of the patient’s atrial flutter? Specifically, has it been present continuously for more than 7 days, and if so, for how long?” The response determines whether I48.0, I48.19, orI48.11 applies.
Common Manifestations and Associated Conditions
Persistent atrial flutter commonly presents with or is complicated by:2,4
- Rapid ventricular response: Palpitations, exertional dyspnea, presyncope; ventricular rate typically 130-150 bpm (2:1 AV conduction)
- Tachycardia-induced cardiomyopathy: Prolonged rapid rates → reversible LV dysfunction → may coexist with I42.9 or I50.xx
- Thromboembolic risk: Atrial stasis → stroke and systemic embolism risk, particularly during cardioversion; associated with I63.xx and I74.xx
- Heart failure exacerbation: Poorly controlled flutter rates precipitate or worsen heart failure; code I50.xx when documented
Coding Manifestations
Always code documented manifestations to fully capture patient complexity. High-yield secondary codes include:
- I50.9 — Heart failure, unspecified (or more specific I50.2x-I50.4x when documented)
- I63.9 — Cerebral infarction (when flutter is the documented cause of cardioembolic stroke)
- N18.30 — Chronic kidney disease, stage 3 (frequent comorbidity; may act as CC)
- E11.9 — Type 2 diabetes mellitus (HCC-mapped; always capture if documented)
💰 HCC Risk Adjustment (CMS-HCC v28)
| Field | Detail |
|---|---|
| CMS-HCC Model Version | v28 (2024-2025 Implementation) |
| HCC Assignment | ❌ Not HCC-Mapped |
| HCC Category | N/A |
| RAF Coefficient | N/A |
I48.19 does not map to an HCC category under CMS-HCC v28 and does not directly contribute to RAF score.
Capture Comorbidities That Do Map
While flutter itself is not HCC-mapped, this patient population frequently carries conditions that are: heart failure (HCC 85), chronic kidney disease stages 3-5 (HCC 136-138), diabetes with complications (HCC 18-19), and ischemic heart disease (HCC 88). Ensuring all documented comorbidities are coded to maximum specificity is the highest-value action in this encounter for risk adjustment purposes.4
🏥 MS-DRG Assignment
MDC 05 — Diseases and Disorders of the Circulatory System
| DRG | Title | Est. Relative Weight* |
|---|---|---|
| DRG 308 | Cardiac Arrhythmia and Conduction Disorders with MCC | ~1.6-1.9 |
| DRG 309 | Cardiac Arrhythmia and Conduction Disorders with CC | ~1.0-1.2 |
| DRG 310 | Cardiac Arrhythmia and Conduction Disorders without CC/MCC | ~0.7-0.9 |
Approximate. Verify against IPPS FY2026 Final Rule tables (CMS MS-DRG Definitions Manual v43).
Sequencing and CC/MCC Capture
When I48.19 is the principal diagnosis, the DRG triplet is 308-310, with the final assignment driven entirely by the presence and POA status of any CC/MCC in the secondary diagnosis list. I48.19 itself functions as a CC when sequenced as a secondary diagnosis alongside another principal. Common MCCs that elevate this admission to DRG 308 include respiratory failure (J96.01), sepsis (A41.9), and acute-on-chronic heart failure (I50.23 or similar). Always review all secondary diagnoses for POA status before finalizing the DRG.5
🔗 Related ICD-10-CM Codes
Atrial Flutter — Duration Variants
| Code | Description |
|---|---|
| I48.0 | Paroxysmal atrial flutter |
| I48.19 | Other persistent atrial flutter ← This Code |
| I48.11 | Longstanding persistent atrial flutter |
Atrial Flutter — Type Variants
| Code | Description |
|---|---|
| I48.3 | Typical atrial flutter (type I, isthmus-dependent) |
| I48.4 | Atypical atrial flutter |
| I48.19 | Other persistent atrial flutter ← This Code |
Related Supraventricular Arrhythmias
| Code | Description |
|---|---|
| I48.91 | Unspecified atrial fibrillation |
| I47.1 | Supraventricular tachycardia |
| I49.1 | Atrial premature depolarization |
🛠️ Commonly Associated CPT Codes (Cardiology / Electrophysiology)
Outpatient and Profee Setting Context
The CPT codes below are most relevant in the outpatient cardiology and electrophysiology profee setting. In the inpatient facility setting, cardioversion and ablation are captured via ICD-10-PCS codes. For profee billing on inpatient encounters, E/M services (99232-99233) with Modifier -25 when a same-day procedure is performed are the standard approach.
| CPT Code | Description | Profee Coding Notes |
|---|---|---|
| 92960 | Cardioversion, elective, electrical conversion of arrhythmia; external | Most common intervention for persistent flutter; bill with I48.19 as primary dx; Modifier -25 if E/M same day |
| 93653 | Comprehensive EP evaluation with ablation of supraventricular arrhythmia | For catheter ablation of flutter circuit; includes EP study — do not separately bill 93600 |
| 93306 | Echocardiography, transthoracic, complete | Frequently ordered to evaluate structural heart disease underlying persistent flutter |
| 93312 | Echocardiography, transesophageal (TEE) | Pre-cardioversion to rule out LAA thrombus; bill separately from cardioversion with appropriate dx linkage |
| 99232 | Subsequent hospital inpatient care, moderate complexity | Standard subsequent care E/M for inpatient flutter management |
NCCI Bundling Considerations
- Cardioversion (92960) billed on the same day as an E/M service requires Modifier -25 on the E/M to establish a separately identifiable service.
- Catheter ablation (93653) includes the EP study component — do not separately bill 93600 (His bundle recording) or basic EP testing codes on the same date.
- TEE (93312) performed immediately before cardioversion may be bundled by some payers; check individual payer policies. Modifier -59 may be required to establish the separate medical necessity of the TEE when both occur same-session.
🔬 ICD-10-PCS Crosswalk (Inpatient Procedures)
When I48.19 is an inpatient diagnosis, these PCS codes are relevant for associated inpatient procedures.
| PCS Section | Body System | Root Operation | Clinical Application |
|---|---|---|---|
| 5 — Extracorporeal | A — Physiological Systems | 2 — Restoration | Electrical cardioversion to restore sinus rhythm: 5A2204Z (Restoration of Cardiac Rhythm, External) |
| 0 — Medical/Surgical | 2 — Heart and Great Vessels | 5 — Destruction | Radiofrequency catheter ablation of flutter circuit: 02583ZZ (Destruction, Conduction Mechanism, Percutaneous) |
| 4 — Measurement & Monitoring | A — Physiological Systems | 0 — Measurement | Electrophysiology study with intracardiac mapping: 4A023N7 (Measurement, Cardiac, Electrical Activity, Percutaneous) |
| 0 — Medical/Surgical | 2 — Heart and Great Vessels | H — Insertion | Permanent pacemaker placement (rate control or SSS post-ablation): 02H63JZ (Insertion, Heart, Pacemaker Lead, Percutaneous) |
💊 Coding Scenarios and Examples
Scenario 1 — Inpatient: Persistent Atrial Flutter with Rapid Ventricular Response, Electrical Cardioversion
Clinical Vignette: A 68-year-old male with a history of hypertension and mild aortic stenosis presents to the ED with 10 days of palpitations and progressive exertional dyspnea. 12-lead ECG reveals atrial flutter with 2:1 AV block and a ventricular rate of 148 bpm. Cardiology is consulted; TEE rules out left atrial appendage thrombus, and the patient undergoes successful electrical cardioversion on hospital day 2, restoring sinus rhythm. Cardiology documents “persistent atrial flutter, atypical type, duration approximately 10 days.”
Principal Diagnosis:
- I48.19 — Other persistent atrial flutter (reason for admission and primary focus of treatment)
Secondary Diagnoses:
- I10 — Essential hypertension (documented comorbidity)
- I35.0 — Nonrheumatic aortic stenosis (documented comorbidity; evaluate for CC/MCC status)
- Z79.01 — Long-term use of anticoagulants (if patient on anticoagulation therapy)
ICD-10-PCS Procedures:
- 5A2204Z — Restoration of Cardiac Rhythm, External (electrical cardioversion)
- 4A023N7 — Measurement, Cardiac Electrical Activity, Percutaneous (TEE guidance/EP monitoring)
MS-DRG Assignment: DRG 310 (without CC/MCC) unless a CC/MCC is documented among secondary diagnoses — review aortic stenosis severity and any acute findings for potential CC/MCC upgrade.
Scenario 2 — Inpatient: Persistent Flutter with Acute Decompensated Heart Failure
Clinical Vignette: A 74-year-old female with known dilated cardiomyopathy and EF of 35% is admitted with worsening dyspnea and 2+ bilateral lower extremity edema. Telemetry captures atrial flutter with variable block. Cardiology documents “persistent atrial flutter contributing to acute exacerbation of systolic heart failure.” Rate control is achieved with IV diltiazem. Cardioversion is deferred pending optimization of volume status.
Principal Diagnosis:
- I50.23 — Acute on chronic systolic (congestive) heart failure (primary reason for admission — heart failure exacerbation)
Secondary Diagnoses:
- I48.19 — Other persistent atrial flutter (CC — contributing etiology)
- I42.0 — Dilated cardiomyopathy (documented underlying structural disease)
- N18.3 — Chronic kidney disease, stage 3 (if documented; CC — common comorbidity in this population)
MS-DRG Assignment: Heart failure DRG triplet (291-293). I48.19 as secondary dx functions as a CC, potentially upgrading from DRG 293 (without CC/MCC) to DRG 292 (with CC) — confirm with DRG grouper based on full secondary dx list.
Scenario 3 — CDI Query: Flutter Duration Undocumented
Clinical Vignette: A 61-year-old male is admitted for rhythm evaluation after an ECG at his PCP’s office shows atrial flutter. The H&P states “atrial flutter — known for several months.” No cardiology note specifies onset date, duration, or whether the flutter has been continuous. The coder cannot determine whether this is paroxysmal, persistent, or longstanding persistent without additional documentation.
Action / Outcome: The 4-character parent code I48.1 cannot be billed. The coder cannot assume duration. A CDI query should be submitted to cardiology: “Documentation indicates atrial flutter for ‘several months.’ To ensure accurate ICD-10-CM code assignment, can you clarify: (1) Has the flutter been continuous since onset, or has it converted to sinus rhythm and recurred? (2) Approximately how many months has it been present continuously? This distinction determines whether the appropriate code is paroxysmal (I48.0), persistent (I48.19), or longstanding persistent (I48.11).”
Query Response: Provider updates documentation to confirm: “Patient has had continuous atrial flutter for approximately 4 months without spontaneous conversion. This represents persistent atrial flutter, atypical type.”
Corrected ICD-10-CM Coding:
- I48.19 — Other persistent atrial flutter (now supported by provider clarification of continuous duration >7 days, <12 months, atypical type)
⚠️ Coding Pitfalls and Tips
| Pitfall or Tip | |
|---|---|
| ❌ | Submitting the 4-character parent code I48.1. This is a non-billable header code and will reject. Always code to the 5th character: I48.19 for other persistent, I48.11 for longstanding persistent. |
| ❌ | Defaulting to I48.19 when duration exceeds 12 months. If the cardiologist documents flutter continuously present for more than 12 months, the correct code is I48.11 — longstanding persistent. Review duration language carefully before code selection. |
| ❌ | Confusing atrial flutter and atrial fibrillation codes. Flutter and fibrillation are distinct arrhythmias with separate code families. I48.19 is flutter. Fibrillation codes fall under I48.0x, I48.1x (different from the I48.1x flutter block — note the structural overlap; verify the index carefully), I48.2x, and I48.9x. |
| ✅ | Query for duration when not explicitly documented. Duration is the primary axis for selecting among I48.0, I48.19, and I48.11. If the record says only “atrial flutter” without specifying paroxysmal, persistent, or longstanding, initiate a CDI query rather than defaulting to unspecified. |
| ✅ | Capture all secondary diagnoses for DRG optimization. I48.19 sits in a DRG triplet (308-310) where the spread between with-MCC and without-CC/MCC can represent significant reimbursement variance. Heart failure, CKD, and respiratory failure are common comorbidities in this population — all should be coded when documented. |
| ✅ | Code tachycardia-induced cardiomyopathy when documented. Prolonged rapid ventricular response from persistent flutter can cause reversible cardiomyopathy. When the cardiologist documents this, add I42.9 or the appropriate I50.xx code — this can shift the DRG and significantly captures patient acuity. |
📚 Sources
- CMS/NCHS. ICD-10-CM Official Guidelines for Coding and Reporting, FY2026. Section I.C.9 — Diseases of the Circulatory System.
- Page RL, Joglar JA, Caldwell MA, et al. (2016). 2015 ACC/AHA/HRS Guideline for the Management of Adult Patients with Supraventricular Tachycardia. Journal of the American College of Cardiology, 67(13), e27-e115. (Source for flutter classification, duration definitions, and ablation approach distinctions.)
- Cosío FG. (2017). Atrial Flutter, Typical and Atypical: A Review. Arrhythmia & Electrophysiology Review, 6(2), 55-62. (Source for type I vs. type II flutter circuit characterization and clinical management.)
- CMS. 2025-2026 Medicare Advantage Risk Adjustment — CMS-HCC Model v28 ICD-10-CM Mappings. (Confirms I48.19 is not HCC-mapped; supports comorbidity capture guidance.)
- CMS. IPPS Final Rule FY2026 — MS-DRG Definitions Manual v43. MDC 05 logic tables; DRG 308-310 grouping criteria and relative weights.