I49.5: Sick sinus syndrome
I49.5, sick sinus syndrome, is listed as a covered diagnosis in 5 Medicare billing and coding articles that apply to 24 HCPCS Level II codes, including A9700 (Supply of injectable contrast material for use in…), C7539 (Insertion of new or replacement of permanent pacemaker…), C7538 (Insertion of new or replacement of permanent pacemaker…). The articles come from 3 Medicare contractors. A listed diagnosis supports medical necessity only; coverage still depends on the LCD's criteria and on documentation in the medical record.
HCPCS Level II codes with I49.5 as a covered diagnosis
| Code | Description | Medicare coverage | DMEPOS fee 2026 (state range) | Articles listing it |
|---|---|---|---|---|
| A9700 | Supply of injectable contrast material for use in echocardiography, per study | Special coverage instructions apply | — | 2 |
| C7539 | Insertion of new or replacement of permanent pacemaker with atrial and ventricular transvenous electrode(s), with insertion of pacing electrode, cardiac venous system, for left ventricular pacing, at time of insertion of implantable defibrillator or pacemaker pulse generator (eg, for upgrade to dual chamber system) | Special coverage instructions apply | — | 1 |
| C7538 | Insertion of new or replacement of permanent pacemaker with ventricular transvenous electrode(s), with insertion of pacing electrode, cardiac venous system, for left ventricular pacing, at time of insertion of implantable defibrillator or pacemaker pulse generator (e.g., for upgrade to dual chamber system) | Special coverage instructions apply | — | 1 |
| C7540 | Removal of permanent pacemaker pulse generator with replacement of pacemaker pulse generator, dual lead system, with insertion of pacing electrode, cardiac venous system, for left ventricular pacing, at time of insertion of implantable defibrillator or pacemaker pulse generator (eg, for upgrade to dual chamber system) | Carrier judgment | — | 1 |
| C7537 | Insertion of new or replacement of permanent pacemaker with atrial transvenous electrode(s), with insertion of pacing electrode, cardiac venous system, for left ventricular pacing, at time of insertion of implantable defibrillator or pacemaker pulse generator (e.g., for upgrade to dual chamber system) | Special coverage instructions apply | — | 1 |
| G0448 | Insertion or replacement of a permanent pacing cardioverter-defibrillator system with transvenous lead(s), single or dual chamber with insertion of pacing electrode, cardiac venous system, for left ventricular pacing | Carrier judgment | — | 1 |
| J0153 | Injection, adenosine, 1 mg (not to be used to report any adenosine phosphate compounds) | Special coverage instructions apply | — | 3 |
| J1250 | Injection, dobutamine hydrochloride, per 250 mg | Special coverage instructions apply | — | 3 |
| J1245 | Injection, dipyridamole, per 10 mg | Special coverage instructions apply | — | 3 |
| Q9957 | Injection, perflutren lipid microspheres, per ml | Carrier judgment | — | 1 |
| Q9956 | Injection, octafluoropropane microspheres, per ml | Carrier judgment | — | 1 |
| Q9950 | Injection, sulfur hexafluoride lipid microspheres, per ml | Carrier judgment | — | 1 |
| Q9955 | Injection, perflexane lipid microspheres, per ml | Carrier judgment | — | 1 |
| J0461 | Injection, atropine sulfate, 0.01 mg | Special coverage instructions apply | — | 2 |
| J0280 | Injection, aminophyllin, up to 250 mg | Special coverage instructions apply | — | 2 |
| J3490 | Unclassified drugs | Special coverage instructions apply | — | 1 |
| A9500 | Technetium tc-99m sestamibi, diagnostic, per study dose | Carrier judgment | — | 1 |
| A9502 | Technetium tc-99m tetrofosmin, diagnostic, per study dose | Carrier judgment | — | 1 |
| A9555 | Rubidium rb-82, diagnostic, per study dose, up to 60 millicuries | Carrier judgment | — | 1 |
| A9505 | Thallium tl-201 thallous chloride, diagnostic, per millicurie | Carrier judgment | — | 1 |
| A9526 | Nitrogen n-13 ammonia, diagnostic, per study dose, up to 40 millicuries | Carrier judgment | — | 1 |
| A4641 | Radiopharmaceutical, diagnostic, not otherwise classified | Carrier judgment | — | 1 |
| A9501 | Technetium tc-99m teboroxime, diagnostic, per study dose | Carrier judgment | — | 1 |
| A9611 | Flurpiridaz f 18, diagnostic, 1 millicurie | Carrier judgment | — | 1 |
Medicare policy articles listing I49.5
- A56391: Billing and Coding: Implantable Automatic Defibrillators (WPS Insurance Corporation (MAC - Part A, MAC - Part B); 5 Level II codes)
- A58503: Billing and Coding: Echocardiography for Myocardial Perfusion (Palmetto GBA (MAC - Part A, MAC - Part B); 5 Level II codes). LCD with the same title: L38786
- A57183: Billing and Coding: Cardiovascular Stress Testing, Including Exercise and/or Pharmacological Stress and Stress Echocardiography (Noridian Healthcare Solutions, LLC (MAC - Part A, MAC - Part B); 4 Level II codes). LCD with the same title: L34324
- A56476: Billing and Coding: Cardiac Radionuclide Imaging (Palmetto GBA (MAC - Part A, MAC - Part B); 13 Level II codes). LCD with the same title: L33457
- A56625: Billing and Coding: Echocardiography (Palmetto GBA (MAC - Part A, MAC - Part B); 6 Level II codes). LCD with the same title: L37379
A diagnosis listed as covered in a billing and coding article supports medical necessity for the article's codes; it does not guarantee payment. Coverage depends on the LCD's criteria, the contractor's jurisdiction and documentation in the medical record.
Other I49 diagnoses (Other cardiac arrhythmias)
- I49.01 — Ventricular fibrillation
- I49.02 — Ventricular flutter
- I49.1 — Atrial premature depolarization
- I49.2 — Junctional premature depolarization
- I49.3 — Ventricular premature depolarization
- I49.40 — Unspecified premature depolarization
- I49.49 — Other premature depolarization
Frequently asked questions
Does Medicare cover I49.5 (Sick sinus syndrome)?
Medicare covers items and services, not diagnoses. 5 Medicare billing and coding articles list I49.5 as a covered diagnosis for 24 HCPCS Level II codes: the diagnosis can support medical necessity for those codes, but payment still depends on the LCD's coverage criteria and the medical record.
Which HCPCS codes can be billed with ICD-10 I49.5?
The Level II codes from the policies most specific to this diagnosis are A9700 (Supply of injectable contrast material for use in…, 2 articles); C7539 (Insertion of new or replacement of permanent pacemaker…, 1 article); C7538 (Insertion of new or replacement of permanent pacemaker…, 1 article); C7540 (Removal of permanent pacemaker pulse generator with…, 1 article); C7537 (Insertion of new or replacement of permanent pacemaker…, 1 article). Code choice depends on the item supplied; check each code's descriptor.
Which Medicare policy articles list I49.5?
A56391 (Billing and Coding: Implantable Automatic Defibrillators); A58503 (Billing and Coding: Echocardiography for Myocardial Perfusion); A57183 (Billing and Coding: Cardiovascular Stress Testing, Including Exercise and/or Pharmacological Stress and Stress Echocardiography), and 2 more articles.
What is ICD-10-CM code I49.5?
I49.5 is the ICD-10-CM code for sick sinus syndrome, in category I49 (Other cardiac arrhythmias), chapter 9: Diseases of the circulatory system.
Next steps
- Run a reimbursement report for a device billed under A9700
- Watch A9700 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for A9700
Sources: CMS Medicare Coverage Database billing and coding articles (covered ICD-10 code lists and HCPCS links); ICD-10-CM FY2026; CMS HCPCS Level II release October 2026; CMS DMEPOS fee schedule 2026 (non-rural state fees). Not billing or legal advice.
Chapter 9: Diseases of the circulatory system · All diagnoses · HCPCS lookup