ICD-10/E73.9

E73.9 ICD 2026 Code: Lactose intolerance, unspecified

E73.9 is the authoritative medical code for Lactose intolerance, unspecified. This classification is used in medical billing and clinical recording to specify the clinical criteria for lactose intolerance, unspecified (ICD-10-CM E73.9), ensuring healthcare documentation aligns with 2026 federal coding standards.

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Official Registry Overview & Definition

Lactose intolerance, unspecified is a billable ICD-10-CM diagnosis code E73.9. Excludes1 (not coded here): androgen insensitivity syndrome E34.5-; congenital adrenal hyperplasia E25.0; hemolytic anemias attributable to enzyme disorders D55.-; Marfan syndrome Q87.4-; 5-alpha-reductase deficiency E29.1. Excludes2 (not included here): Ehlers-Danlos syndromes Q79.6-.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for E73.9 in the official ICD-10-CM tabular list.

Excludes1 — Not Coded Here

Conditions that can never be reported with this code; the two are mutually exclusive.

  • androgen insensitivity syndrome E34.5-
  • congenital adrenal hyperplasia E25.0
  • hemolytic anemias attributable to enzyme disorders D55.-
  • Marfan syndrome Q87.4-
  • 5-alpha-reductase deficiency E29.1

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

  • Ehlers-Danlos syndromes Q79.6-

Frequently Asked Questions (FAQ) & Clinical Guidance

What can't be coded together with E73.9?

Per Excludes1 instructions, E73.9 must not be reported with: androgen insensitivity syndrome (E34.5-); congenital adrenal hyperplasia (E25.0); hemolytic anemias attributable to enzyme disorders (D55.-); Marfan syndrome (Q87.4-).

Can E73.9 be reported alongside related conditions?

Per Excludes2 instructions, E73.9 and the following may both be reported when both are present: Ehlers-Danlos syndromes (Q79.6-).

Codes in This Family (4)

Official ICD-10-CM classifications in the same code family as E73.9, with their registry titles.

  • E73 — Lactose intolerance
  • E73.0 — Congenital lactase deficiency
  • E73.1 — Secondary lactase deficiency
  • E73.8 — Other lactose intolerance

Indexed Clinical Terms (5)

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code.

  • Deficiency, deficient, disaccharidase
  • Intolerance, lactose
  • Intolerance, milk NEC, lactose
  • Malabsorption, disaccharide
  • Malabsorption, lactose

Related Codes & Numerical Sequence (Crawl Map)

Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures:

ICD Code E70.9 Disorder of aromatic amino-acid metabolism, unspecified
ICD Code E72.9 Disorder of amino-acid metabolism, unspecified
ICD Code E74.9 Disorder of carbohydrate metabolism, unspecified
ICD Code E76.9 Glucosaminoglycan metabolism disorder, unspecified
ICD Code E77.9 Disorder of glycoprotein metabolism, unspecified
ICD Code E78.9 Disorder of lipoprotein metabolism, unspecified
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