ICD-10 Code for Transaminitis: R74.01, Elevated Liver Enzymes, and Coding Guidelines

A patient’s liver panel is positive for AST and ALT; however, there has been no diagnosis of a specific liver condition by the physician. What coding would be appropriate in this situation?

The ICD-10 code for transaminitis is the R74.01 code, and it refers to increased transaminases, which include both aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The R74.01 code is a diagnosis code that physicians usually use when there are increased transaminases without any diagnosed disease.

Not all elevated liver test results will fall under R74.01. Both the enzyme, physician’s diagnosis, and the purpose of the encounter are important factors when choosing the right code.

This FY2027 guide provides details about what codes to use, how to document appropriately, common errors, and tips on coding.

What Is Transaminitis?

• Transaminitis is a condition that has elevated amounts of liver transaminase enzymes in the bloodstream. Some of the transaminase enzymes measured by physicians are:
• Alanine aminotransferase (ALT): ALT enzyme is mostly located in the liver. High ALT enzyme levels are an indicator of liver cell damage.
• Aspartate aminotransferase (AST): An enzyme that is found in the liver as well as other organs like muscles. Hence, high levels of AST enzymes do not mean that there is liver disease.

Transaminitis is not a medical condition but a finding seen in laboratories.

For instance, the doctor will see high levels of ALT in a routine blood test and conduct further tests to understand the reason behind this. Until the doctor makes the actual diagnosis, it might be justified to report the abnormality found..

What Causes Elevated Liver Transaminases?

Several conditions and factors can increase AST or ALT levels, including:

• Metabolic Dysfunction Associated Steatohepatitis (MASLD)
• Viral Hepatitis and Other Liver Infections
• Alcohol Related Liver Injury
• Drug Induced Liver Injury
• Muscle Injuries and Vigorous Exercise
• Other Inflammatory or Metabolic Disorders

However, coders may not use any of these codes merely based on lab values. The treating physician must first establish the diagnosis.

ICD-10 Code for Transaminitis: R74.01

ICD-10-CM code for FY 2027 specifies R74.01 – Increase in levels of transaminases of the liver.

The said coding is classified under the category R74, which covers abnormal serum enzyme levels.

It includes an increase in levels of AST and ALT. This code is assigned whenever there is an increase in the transaminase level mentioned by the physician.

Important Details About R74.01

• Code: R74.01
• Definition: Elevated liver transaminases levels
• Classification: R74 – Abnormal serum enzyme levels
• Code type: ICD-10-CM Diagnostic code
• Billable: Can be used in billing
• Coding year: FY2027

Healthcare professionals should review the current Alphabetic Index, Tabular List, and official coding guidelines before finalizing code selection.

ICD-10 Codes for Elevated Liver Enzymes

The phrase elevated liver enzymes does not always identify the specific laboratory abnormality. Therefore, coding teams need to distinguish transaminase elevations from other enzyme abnormalities.

ICD-10-CM code	Official description	Common documentation context
R74.01	Elevation of levels of liver transaminase levels	Elevated AST, ALT, or transaminases
R74.8	Abnormal levels of other serum enzymes	Abnormal alkaline phosphatase or another specified serum enzyme
R74.9	Abnormal serum enzyme level, unspecified	Provider identifies a serum enzyme abnormality without specifying the enzyme
R79.89	Other specified abnormal findings of blood chemistry	General abnormal liver function test findings without a more specific documented abnormality

Coding difference: R74.01 is more specific than an abnormal lab result code to indicate elevated AST or ALT levels. R74.8 is not necessarily coded when there is an elevated liver enzyme level.

Elevated AST ICD-10 Code

The appropriate ICD-10-CM coding for high AST in the documentation is R74.01. This is assuming that the chart supports the coding of this condition.

Increased AST may be due to liver damage, muscle damage, and many other conditions. Thus, increased AST levels do not diagnose liver disease.

Elevated ALT ICD-10 Code

Healthcare providers generally use R74.01  for elevated ALT when they have not established a related definitive diagnosis.

For instance, a primary care physician may document elevated ALT, review the patient’s medication history, and request repeat testing. In that situation, R74.01 may accurately represent the finding under evaluation.

When Does R74.8 Apply?

R74.8 covers the abnormal serum level of other enzymes.

For instance, the doctor may note the increased alkaline phosphatase without providing the underlying reason for this. The coder may refer to R74.8 and use the proper classification.

As for AST and ALT, there is a distinct code assigned to them; thus, one should not substitute R74.8 with R74.01 just because they fall under the category of R74.

Transaminitis vs. Abnormal Liver Function Tests

Providers often use transaminitis, high liver enzymes, and abnormal liver function tests synonymously during discussions.

But these terms may not always have the same coding significance.

Transaminitis is a term used to describe high transaminases, especially AST and ALT levels.

Abnormal liver function tests could be anything from bilirubin, albumin, or any other tests.

In a case where a physician documents an abnormal liver panel without specifying the specific test abnormality, then it will be better to use R79.89 code rather than R74.01 code.

Therefore, billing staff need to be certain about the exact abnormality before coding.

How to Document Transaminitis for Accurate ICD-10 Coding

Accurate diagnosis coding starts with a clear clinical assessment rather than the laboratory report alone.

reporting alone.

1. Abnormal Enzyme Identification

It is necessary for the provider to indicate whether it is AST, ALT, or both enzymes that fall out of the reference range at the laboratory.

For example, writing “abnormal ALT levels” provides much more detail to the coder than using the phrase “abnormal blood work results” generally.

2. Document the Clinical Assessment

It is important for the doctor to provide details on how abnormal results are clinically significant and what the doctor’s assessment was.

Details such as symptoms, history, medications, risk factors, and the investigation plan can be used.

3. Identify the Underlying Disease

If the doctor identifies the disease that causes abnormal enzymes, it is important for the coder to code the disease first before considering transaminitis separately.

4. State the Rationale Behind the Additional Tests

The physician could order additional laboratory tests or imaging procedures because of the persistently high levels of enzymes.

It is important to have well-documented rationale related to the reason behind the ordering of the tests.

Transaminitis ICD-10 Coding Guidelines for FY2027

The official ICD-10-CM guidelines provide several principles that directly affect transaminase coding.

Report an Abnormal Finding When No Definitive Diagnosis Exists

A documented abnormality could be reported by healthcare personnel when the doctor has not made a definite diagnosis yet.

For instance, a patient comes back for evaluation because of high AST and ALT. The doctor documents transaminitis and conducts further tests to confirm liver disease.

Here, R74.01 could be helpful in diagnosis coding.

Avoid Coding Suspected Diagnoses as Confirmed in Outpatient Settings

When a patient presents for outpatient treatment, it is incorrect to code a diagnosis which is questionable. If the physician’s documentation of the patient shows “possible hepatitis” due to raised levels of the liver enzymes, the coder cannot code hepatitis because it may not be proven.

The coder needs to document the symptoms or signs documented by the physician.

Avoid Unnecessary Additional Codes

If a disease is established by a doctor, the coders should not automatically code any other findings associated with the disease as separate diagnoses.

An extra code can be included if the findings are worthy of being reported separately based on the guidelines.

Before deciding to include R74.01, the coders must first determine whether the findings are related to the diagnosed disease.

Select Codes Based on the Date of Service

ICD-10-CM codes for Fiscal Year 2027 have been developed to be used from October 1, 2026, through September 30, 2027.

Code sets should be assigned according to the year corresponding to the date of the service.

Practical Transaminitis Coding Examples

Examples of realistic claim situations can be used to describe how the information in documentation can influence the choice of diagnosis codes.

Scenario 1: : AST and ALT Elevation without Diagnosis

In a metabolic profile test of a patient, a primary care doctor discovers elevated AST and ALT. The transaminitis is documented and additional testing is scheduled.

Potential code: R74.01

In this case, the doctor identifies the transaminase elevation but does not establish any liver disease.

Scenario 2:  Elevation of Alkaline Phosphatase

During a routine visit of the patient, a provider finds out that the patient has elevated alkaline phosphatase. The enzyme elevation is documented but the reason for that is not confirmed yet.

Potential code: R74.8

In the documentation, there is a specified enzyme, which is not AST and ALT.

Scenario 3: Diagnosed Liver Problem

The patient undergoes a gastroenterology evaluation, which results in a confirmed liver problem.

Coding strategy: Check the code for the identified liver disease and see if there is a need to separately code for the abnormal liver enzymes.

It is not correct to code both R74.01 and the disease code together.

Scenario 4: Abnormalities in Liver Panel without Detail

The physician reports abnormalities in the liver panel but does not indicate the actual abnormal values.

Code suggestion: R79.89

The coding department needs to assess the information at hand and decide on any necessary clarifications.

Common Transaminitis Coding Mistakes

Even minor issues with documentation and code selection may lead to avoidable corrections of the claims.

Using Code R74.8 for Any Elevated Liver Enzyme

There are billing staff who select code R74.8 in case of any elevation of the liver enzymes mentioned in the medical record.

However, code R74.01 is used to report elevated AST and ALT. Thus, the coders need to know which enzyme was elevated.

Assigning Liver Disease in Absence of the Physician’s Documentation

The lab report may indicate that there is liver injury; however, it does not mean that there is hepatitis, cirrhosis, or other disease.

Coders must never assume that there is any disease just based on the laboratory results.

Coding the Same Abnormality by Different Codes

The coder may decide to code R74.01 and R79.89 as there is a single documented transaminase abnormality. This practice may lead to unnecessary coding duplicates. In order to avoid that, coders must select codes that correspond to each independent reportable abnormality.

Not Using Documented Information Provided by the Provider

Sometimes coders use general statements like “abnormal labs.” Providers can help coders if they document the specific information about the abnormality.

Medical Billing Considerations for Elevated Liver Enzymes

Choosing the proper ICD-10-CM code is just one step in the process of billing.

Healthcare facilities have to link their documentation of diagnosis or findings with their services rendered.

Laboratory Testing and Medical Necessity

The physician may call for hepatic function panels or single liver enzyme tests to be done during the diagnosis of transaminitis.

For instance, some CPT codes are as follows:

• 80076: Hepatic function panel.
• 84450: Aspartate aminotransferase (AST).
• 84460:Alanine aminotransferase (ALT).

CPT codes represent the laboratory services done while ICD-10-CM codes represent the reason for the laboratory tests.

The billers should verify the order of the physician, the test done, and other payer guidelines.

E/M Services and Follow-Up Visits

A patient may need a visit to address concerns about his/her persistently high liver enzyme levels, medication review, or planning for further testing.

In such cases, it is important for the provider to document the medically necessary history, exam where appropriate, and medical decision making or time.

It is critical for the billing department to assign an E/M code based on the CPT guidelines and not simply because of abnormal lab values of the patient.

Payer Requirements and Claim Review

Coverage for the provision of lab services might be governed by different rules by commercial insurers and Medicare contractors.

1. Hence, it is imperative that the practice:
2. Confirms the patient’s coverage and benefits.
3. Determines the necessary medical requirements.
4. Codes according to the provided diagnosis.
5. Examines claims for rejection or denial prior to resubmission.

Important: A valid ICD-10-CM code does not guarantee that an insurer will cover or reimburse a service.

How Practices Can Improve Transaminitis Claim Accuracy

A consistent billing process will require coordination among physicians, lab personnel, coders, and revenue cycle staff.

For one thing, ensure providers capture the accurate abnormal findings in their reports instead of giving vague information.

Secondly, verify whether coders have an understanding of the distinction between R74.01, R74.8, and R79.89 codes.

Furthermore, assess denials related to laboratories to determine any gaps in documentation, limitations in coverage, or inconsistencies in diagnostic coding.

Lastly, ensure an annual update of coding resources based on any changes made to the ICD-10-CM codes.

Conclusion

Transaminitis is denoted by ICD-10 code R74.01; it denotes the condition characterized by elevation of the level of liver transaminases such as AST and ALT.

R74.8 and R79.89 deal with laboratory abnormalities that are not covered by other codes. Correct coding requires the documentation by the doctor, the nature of the laboratory abnormality, and the confirmed diagnosis.

Using the proper distinctions among these laboratory abnormalities according to ICD-10-CM FY2027 will make the coding process more efficient.