R84.4 ICD-10-CM Code: Abnormal immunological findings in specimens from respiratory organs and thorax
HCC Buddy Code Card
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FY 2026 Apr update / Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99) / Abnormal findings on examination of other body fluids, substances and tissues, without diagnosis (R83-R89)
R84.4
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceAbnormal immunological findings in specimens from respiratory organs and thorax
Test results from lung or chest samples show abnormal immune system markers or antibody levels.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
N/A—
Not mapped
ACA/HHS
N/A—
Not mapped
ESRD/PACE
N/A—
Not mapped
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for R84.4 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for R84.4 in this effective period.
Related Child Codes
Includes
Official- abnormal findings in bronchial washings
- abnormal findings in nasal secretions
- abnormal findings in pleural fluid
- abnormal findings in sputum
- abnormal findings in throat scrapings
Excludes 1
Official- blood-stained sputum (R04.2)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for R84.4 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for R84.4 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for R84.4 in this effective period.
Buddy Documentation Tip
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is R84.4 an HCC code?
No. R84.4 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
- Code
- R84.4
- Description
- Abnormal immunological findings in specimens from respiratory organs and thorax
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF
- —
- Billable
- Yes
- Payment year
- 2026
Coder workflow notes
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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
R84.4 is the ICD-10-CM diagnosis code for abnormal immunological findings in specimens from respiratory organs and thorax. Test results from lung or chest samples show abnormal immune system markers or antibody levels. R84.4 sits in the ICD-10-CM chapter for symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (r00-r99), within the section covering abnormal findings on examination of other body fluids, substances and tissues, without diagnosis (r83-r89).
R84.4 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Use when immunological testing of respiratory specimens reveals abnormal findings.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for R84.4 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use when immunological testing of respiratory specimens reveals abnormal findings
- •Consider linking with relevant immune-related diagnoses for complete clinical picture