MASLD and MASH vs NAFLD and NASH: ICD-10-CM Coding Guidance

Overview of Evolving Liver Disease Terminology

ICD-10-CM Coding Quality Education Tip

Clinical terminology has evolved; ICD-10-CM coding has not yet fully aligned.

MASLD vs NAFLD: Coding Considerations

• MASLD – Metabolic dysfunction–Associated Steatotic Liver Disease
• A clinical term describing fatty liver disease associated with metabolic dysfunction (e.g., obesity, diabetes, dyslipidemia).
• NAFLD – Nonalcoholic Fatty Liver Disease
• The current ICD-10-CM terminology used to classify fatty liver disease not due to alcohol.
• ICD-10-CM Status: ICD-10-CM does not yet recognize MASLD as a distinct diagnosis.
• Coding Guidance:
• Assign the most accurate NAFLD-related ICD-10-CM code based on documentation.
• K76.0 – Fatty (change of) liver, not elsewhere classified
• Query if alcohol use, metabolic risk factors, or disease etiology are unclear.

MASH vs NASH: Coding Considerations

• MASH – Metabolic dysfunction–Associated Steatohepatitis
• A clinical term describing steatohepatitis associated with metabolic dysfunction.
• NASH – Nonalcoholic Steatohepatitis
• The current ICD-10-CM terminology for nonalcoholic steatohepatitis.
• ICD-10-CM Status: There is no distinct ICD-10-CM code for MASH at this time.
• Coding Guidance:
• When documentation states metabolic dysfunction–associated steatohepatitis, report:
• K75.81 – Nonalcoholic steatohepatitis
• Confirm documentation supports steatohepatitis and excludes alcohol-related liver disease.

Key ICD-10-CM Coding Takeaways

• Code to the ICD-10-CM classification, not evolving clinical terminology.
• Metabolic dysfunction–Associated Steatotic Liver Disease → Nonalcoholic Fatty Liver Disease ICD-10-CM codes.
• Metabolic dysfunction–Associated Steatohepatitis → Nonalcoholic Steatohepatitis (K75.81).
• Query when documentation lacks specificity or conflicting terminology is used.

Works Cited

American Association for the Study of Liver Diseases (AASLD). (2023). New nomenclature for NAFLD and NASH. Available at: https://www.aasld.org/practice-guidelines/new-nomenclature-nafld-and-nash

Journal of Hepatology. (2023). A new definition for metabolic dysfunction–associated fatty liver disease. Available at: https://www.journal-of-hepatology.eu/article/S0168-8278(23)00093-0/fulltext

Centers for Disease Control and Prevention. (2024). ICD-10-CM. Available at: https://www.cdc.gov/nchs/icd/icd-10-cm.htm

Centers for Medicare & Medicaid Services. (2024). ICD-10 coding resources. Available at: https://www.cms.gov/medicare/coding/icd10