2026 ICD-10-CM Diagnosis Code R74.9Abnormal serum enzyme level, unspecified

ICD-10-CM Codes›R00–R99›R70-R79›R74

ICD-10-CM R74.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R74.9 is a billable ICD-10-CM diagnosis code for abnormal serum enzyme level, unspecified. 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. Coders also document this condition as high enzyme level in serum. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abnormal findings without diagnosis.

Code Identity

ICD-10-CM Code
R74.9
Billable Status
Yes — Valid for Submission
Code Describes
Abnormal serum enzyme level, unspecified
Short Description
Abnormal serum enzyme level, unspecified
Same as the full description in the CMS dataset.
Parent Code
R74
Abnormal serum enzyme levels

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR70-R79Abnormal findings on examination of blood, without diagnosis
CategoryR74Abnormal serum enzyme levels
This CodeR74.9Abnormal serum enzyme level, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • High enzyme level in serum

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.

    • Abnormal, abnormality, abnormalities
      • serum level (of)
        • enzymes

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

Convert R74.9 to ICD-9-CMHistory

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

ICD-9-CM
790.5 Abn serum enzy level NEC
Approximate The match is approximate rather than exact.

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 R74.9Overview

Is R74.9 (Abnormal serum enzyme levels) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report abnormal serum enzyme level, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does R74.9 group to?

When abnormal serum enzyme level, unspecified 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 R74.9 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the abnormal serum enzyme level, unspecified is established, that condition takes the principal position instead.

What is the ICD-9 equivalent of R74.9?

Under the General Equivalence Mappings, abnormal serum enzyme level, unspecified converts to ICD-9-CM 790.5 (abn serum enzy level NEC). The mapping is approximate, so confirm the match fits the documentation.

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.