ICD-10 I49.5
Billable / Specific HCC v28: 96Sick sinus syndrome
About ICD-10-CM I49.5
ICD-10-CM code I49.5 represents Sick sinus syndrome. This is a billable/specific code in the Circulatory System chapter (block I49). The 2026 edition of ICD-10-CM I49.5 became effective on October 1, 2025.
Coding Tips for I49.5
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
I49.5 is a CMS-HCC v28 risk-adjustment code (category 96). To count for the patient Risk Adjustment Factor (RAF), document the diagnosis with MEAT language each calendar year: Monitored, Evaluated, Assessed, Treated. A diagnosis on the problem list alone does not satisfy CMS RADV audit standards. Include the diagnosis in the assessment with current status and current treatment plan.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under I49.5. Per CMS ICD-10-CM Tabular 2026.
- Tachycardia-bradycardia syndrome
Medicare Advantage HCC Impact
Capture this diagnosis annually for accurate risk adjustment. Missed HCC captures are the #1 revenue leak in Medicare Advantage risk programs.
Medicare LCD Coverage for I49.5
Local Coverage Determinations (LCDs) from CMS MACs that list I49.5 as a covered diagnosis.
Showing top 10 of 373 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing I49.5.
1 Aetna
1 Cigna
5 Medicare
CPT Codes Commonly Billed with I49.5
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 33208 CMS LCD: Billing and Coding: Single Chamber and Dual Chamber Permanent Cardiac Pacemakers � Coding and Billing CMS LCD
- 33206 CMS LCD: Billing and Coding: Single Chamber and Dual Chamber Permanent Cardiac Pacemakers � Coding and Billing CMS LCD
- 33207 CMS LCD: Billing and Coding: Single Chamber and Dual Chamber Permanent Cardiac Pacemakers � Coding and Billing CMS LCD
- 0573T CMS LCD: Billing and Coding: Implantable Automatic Defibrillators CMS LCD
- 0574T CMS LCD: Billing and Coding: Implantable Automatic Defibrillators CMS LCD
- 0614T CMS LCD: Billing and Coding: Implantable Automatic Defibrillators CMS LCD
- 0577T CMS LCD: Billing and Coding: Implantable Automatic Defibrillators CMS LCD
- 0572T CMS LCD: Billing and Coding: Implantable Automatic Defibrillators CMS LCD
- 0576T CMS LCD: Billing and Coding: Implantable Automatic Defibrillators CMS LCD
- 0575T CMS LCD: Billing and Coding: Implantable Automatic Defibrillators CMS LCD
Convert I49.5 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| I49.5 | 42781 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To I49.5
Other codes in section I30-I5A (Other forms of heart disease).
ICD-10 I49.5, Billing FAQ
Is ICD-10 code I49.5 billable? +
Yes, I49.5 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to I49.5? +
ICD-10 I49.5 includes: Tachycardia-bradycardia syndrome.
Does I49.5 affect Medicare Advantage HCC risk adjustment? +
Yes. I49.5 maps to CMS-HCC v28 category 96. Capture this diagnosis annually for accurate Medicare Advantage risk score.
What CPT codes are commonly billed with I49.5? +
Procedures frequently paired with I49.5 include: 33208, 33206, 33207, 0573T, 0574T.
What ICD-9 codes does I49.5 map to? +
Per CMS GEMs, I49.5 maps to ICD-9 codes: 42781. Useful for legacy data review and historical claim analysis.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
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