Version 2024

2024 ICD-10-CM Diagnosis Code E73

Lactose intolerance

ICD-10-CM Code:
E73
ICD-10 Code for:
Lactose intolerance
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

  • Endocrine, nutritional and metabolic diseases
    (E00–E89)
    • Metabolic disorders
      (E70-E88)
      • Lactose intolerance
        (E73)

E73 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of lactose intolerance. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding Applicable to Lactose intolerance

Non-specific codes like E73 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for lactose intolerance:

  • Use E73.0 for Congenital lactase deficiency - BILLABLE CODE

  • Use E73.1 for Secondary lactase deficiency - BILLABLE CODE

  • Use E73.8 for Other lactose intolerance - BILLABLE CODE

  • Use E73.9 for Lactose intolerance, unspecified - BILLABLE CODE

Clinical Information

  • Lactose Intolerance

    the condition resulting from the absence or deficiency of lactase in the mucosa cells of the gastrointestinal tract, and the inability to break down lactose in milk for absorption. bacterial fermentation of the unabsorbed lactose leads to symptoms that range from a mild indigestion (dyspepsia) to severe diarrhea. lactose intolerance may be an inborn error or acquired.

Patient Education


Lactose intolerance

Lactose intolerance is a condition that makes it difficult to digest lactose, a sugar found in milk and several other dairy products. Lactose is normally broken down by an enzyme called lactase, which is produced by cells in the lining of the small intestine. Lack or loss of lactase has both genetic and non-genetic causes.

Congenital lactase deficiency, also called congenital alactasia, is a disorder in which infants are unable to break down the lactose in breast milk or formula. This form of lactose intolerance results in very severe diarrhea. If affected infants are not given a lactose-free infant formula, they may experience severe dehydration and weight loss.

Lactose intolerance in adulthood can be caused by the reduced production of lactase after infancy (lactase nonpersistence). If individuals with lactose intolerance consume lactose-containing dairy products, they may experience abdominal pain, bloating, flatulence, nausea, and diarrhea beginning 30 minutes to 2 hours later.

Most people with lactase nonpersistence retain some lactase activity and can include varying amounts of lactose in their diets without experiencing symptoms. Often, affected individuals have difficulty digesting fresh milk but can eat certain dairy products such as cheese or yogurt without discomfort. These foods are made using fermentation processes that break down much of the lactose in milk.


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Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.