2026 ICD-10-CM Diagnosis Code R97.1Elevated cancer antigen 125 [CA 125]

ICD-10-CM Codes›R00–R99›R97›R97

ICD-10-CM R97.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R97.1 is a billable ICD-10-CM diagnosis code for elevated cancer antigen 125 [CA 125]. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 947 through 948. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abnormal findings without diagnosis.

Code Identity

ICD-10-CM Code
R97.1
Billable Status
Yes — Valid for Submission
Code Describes
Elevated cancer antigen 125 [CA 125]
Short Description
Elevated cancer antigen 125 [CA 125]
Same as the full description in the CMS dataset.
Parent Code
R97
Abnormal tumor markers

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR97Abnormal tumor markers
CategoryR97Abnormal tumor markers
This CodeR97.1Elevated cancer antigen 125 [CA 125]

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Elevated, elevation
      • cancer antigen 125 [CA 125]

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR SYM017
Abnormal findings without diagnosis
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

CA-125 Blood Test (Ovarian Cancer)

This test measures the amount of a protein called CA-125 (cancer antigen 125) in a sample of your blood. CA-125 is a type of tumor marker. Tumor markers are substances that are often made by cancer cells or by normal cells in response to cancer.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert R97.1 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
795.82 Elev ca antigen 125
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About R97.1Overview

Is R97.1 (Abnormal tumor markers) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report elevated cancer antigen 125 [CA 125] on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does R97.1 group to?

When elevated cancer antigen 125 [CA 125] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 947, 948, with relative weights from 0.8005 to 1.2694 depending on complications. Higher weights mean higher Medicare reimbursement.

Can R97.1 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the elevated cancer antigen 125 [CA 125] is established, that condition takes the principal position instead.

What is the ICD-9 equivalent of R97.1?

Under the General Equivalence Mappings, elevated cancer antigen 125 [CA 125] converts to ICD-9-CM 795.82 (elev ca antigen 125). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.