Question 1

What is ICD-10 code R55?

Accepted Answer

R55 is the ICD-10-CM diagnosis code for Syncope and collapse. A sudden loss of consciousness and collapse, often accompanied by a brief loss of muscle tone. The person typically recovers quickly without lasting effects. R55 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. R55 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Question 2

Is R55 an HCC code?

Accepted Answer

No. R55 is a billable ICD-10-CM code but does not map to any payment HCC category under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can still be reported on Medicare Advantage encounter data submissions, but it does not contribute to the beneficiary's Risk Adjustment Factor (RAF) score and therefore does not affect the risk-adjusted capitation payment to the plan. V28 reached 100% phase-in for payment year 2026.

Question 3

Is R55 billable?

Accepted Answer

Yes. R55 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. R55 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Question 4

What is the V28 vs V24 difference for R55?

Accepted Answer

R55 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards R55 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

Question 5

What should coders know when reporting R55?

Accepted Answer

Investigate and document the cause of syncope (heart rhythm problems, low blood pressure, neurological issues) Code any identified underlying cause in addition to this symptom code

R55

Is R55 an HCC code?

What This Code Means

Coding Tips

Excludes 1 — Do NOT code together

Code Hierarchy

Open R55 in the Interactive Encoder