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I49.5

I49.5Sick sinus syndrome

Billable / specific codeICD-10-CM

I49.5 is a billable, specific ICD-10-CM code for sick sinus syndrome. It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Tachycardia-bradycardia syndrome

Risk adjustment

I49.5 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

  • HCC 238 Specified Heart Arrhythmias0.299 RAF

Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.

Medicare coverage

I49.5 is named in 32 Medicare coverage policies 32 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A54831Billing and Coding: Single Chamber and Dual Chamber Permanent Cardiac Pacemaker
  • A54909Billing and Coding: Single Chamber and Dual Chamber Permanent Cardiac Pacemakers
  • A54926Billing and Coding: Single Chamber and Dual Chamber Permanent Cardiac Pacemakers
  • A54929Billing and Coding: Single Chamber and Dual Chamber Permanent Cardiac Pacemakers – Coding and Billing

How I49.5 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to I49.5.

  • Bradytachycardia
  • Pause, sinoatrial
  • Bradycardiatachycardia syndrome
  • Dysfunctionsinoatrial node
  • Sicksinus(syndrome)
  • Syndromebradycardia-tachycardia
  • Syndrometachycardia-bradycardia
  • Tachycardiasick sinus
  • Syndromesicksinus
  • Tachycardiaparoxysmalwith sinus bradycardia

Related codes at this level

Codes that share I49. If I49.5 is not quite right, the correct code is usually one of these.

Questions about I49.5

Is I49.5 a billable ICD-10-CM code?
Yes. I49.5 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does I49.5 sit in the tabular list?
Diseases of the circulatory system (I00-I99), in the block Other forms of heart disease (I30-I5A).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.