E73 ICD-10-CM Code: Lactose intolerance
Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.
Coding at a Glance
- Tabular directives
- 5 Excludes1 · 1 Excludes2
Coding instructions
Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for E73 in the official ICD-10-CM tabular list, quoted as published.
Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025
Notes without a marker are published on E73 itself; “inherited from” names the category or block whose note applies here.
Excludes1 — Not Coded Here
Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
- androgen insensitivity syndrome (E34.5-) Compare E73 vs E34.5 →
- congenital adrenal hyperplasia (E25.0) Compare E73 vs E25.0 →
- hemolytic anemias attributable to enzyme disorders (D55.-) Compare E73 vs D55 →
- Marfan syndrome (Q87.4-) Compare E73 vs Q87.4 →
- 5-alpha-reductase deficiency (E29.1) Compare E73 vs E29.1 →
Source: inherited from E70-E88
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-) Compare E73 vs Q79.6 →
Source: inherited from E70-E88
Coder workflow for E73
MedCoder structured workflow — derived from this code’s own official record
Before you code E73
- E73 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).
ReviewE73.0, E73.1, E73.8, E73.9
See the relationships section · Guide: How to choose an ICD-10-CM code →
- Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with E73. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).
Choose the right path
- Does the documentation support one of the more specific codes beneath E73?
Yes → Select that code and continue the checks below on its own page.
No → E73 cannot be reported as written; query for the specificity its subcategory needs. - Does the documentation support a condition named in E73’s Excludes1 note?
Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
No → Continue.
Consider E73. Then confirm the code is valid for the date of service in the Verify section.
Documentation check
- The provider’s diagnostic statement
- Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Official instructions as workflow
Excludes1 — check before selecting E73(5 notes)
Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with E73: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.
CompareE34.5, E25.0, D55, Q87.4, E29.1
See the official tabular notes · Guidelines I.A.12.a
Excludes2 — not part of E73(1 note)
Coding workflow: The conditions named in this note are not included in E73. When the record documents both, both may be reported; the note is a boundary, not a prohibition.
CompareQ79.6
See the official tabular notes · Guidelines I.A.12.b
Coding decision scenarios
Pattern scenarios for this code’s structure — decision rules, not clinical cases
Documentation: Both the condition E73 describes and a condition named in its Excludes1 note are documented for the same encounter.
Coding question: Can both codes be reported?
Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.
Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).
Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.
Code Overview
MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.
Verify Before Coding
From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.
Relationships & Classification
MedCoder structured relationships — computed from published CMS and AHRQ datasets
Other codes that name E73 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.
Referenced by 7 Excludes1 notes across 3 chapters: P59 — Neonatal jaundice from other and unspecified causes, R79 — Other abnormal findings of blood chemistry, R80 — Proteinuria, R80-R82 — Abnormal findings on examination of urine, without diagnosis (R80-R82), R81 — Glycosuria, R82 — Other and unspecified abnormal findings in urine, Z91.011 — Allergy to milk products.
These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.
Referenced by 6 Excludes2 notes across 4 chapters: E74.3 — Other disorders of intestinal carbohydrate absorption, G11 — Hereditary ataxia, G71 — Primary disorders of muscles, K90.4 — Other malabsorption due to intolerance, N25.0 — Renal osteodystrophy, N25.81 — Secondary hyperparathyroidism of renal origin.
These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.
Referenced by 2 Code First instructions across 2 chapters: G63 — Polyneuropathy in diseases classified elsewhere, H42 — Glaucoma in diseases classified elsewhere.
Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.
Contextual Map
Every relationship of E73 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.
Run E73 with these 21 related codes in Claim Check
Hierarchy
- E00-E89 — Chapter 4: Endocrine, Nutritional and Metabolic Diseases (E00-E89) (E00-E89)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- E70-E88 — Metabolic disorders[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
Excludes1
- D55 — Anemia due to enzyme disorders[Excludes1]: “hemolytic anemias attributable to enzyme disorders (D55.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- E25.0 — Congenital adrenogenital disorders associated with enzyme deficiency[Excludes1]: “congenital adrenal hyperplasia (E25.0)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- E29.1 — Testicular hypofunction[Excludes1]: “5-alpha-reductase deficiency (E29.1)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- E34.5 — Androgen insensitivity syndrome[Excludes1]: “androgen insensitivity syndrome (E34.5-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- Q87.4 — Marfan syndrome[Excludes1]: “Marfan syndrome (Q87.4-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Excludes2
- Q79.6 — Ehlers-Danlos syndromes[Excludes2]: “Ehlers-Danlos syndromes (Q79.6-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Referenced by Excludes1 notes
- P59 — Neonatal jaundice from other and unspecified causes[Excludes1]: “jaundice due to inborn errors of metabolism (E70-E88)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- R79 — Other abnormal findings of blood chemistry[Excludes1]: “specific findings indicating disorder of carbohydrate metabolism (E73-E74)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- R80 — Proteinuria[Excludes1]: “specific findings indicating disorder of carbohydrate metabolism (E73-E74)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- R80-R82 — Abnormal findings on examination of urine, without diagnosis (R80-R82)[Excludes1]: “specific findings indicating disorder of carbohydrate metabolism (E73-E74)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- R81 — Glycosuria[Excludes1]: “specific findings indicating disorder of carbohydrate metabolism (E73-E74)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- R82 — Other and unspecified abnormal findings in urine[Excludes1]: “specific findings indicating disorder of carbohydrate metabolism (E73-E74)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- Z91.011 — Allergy to milk products[Excludes1]: “lactose intolerance (E73.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Referenced by Excludes2 notes
- E74.3 — Other disorders of intestinal carbohydrate absorption[Excludes2]: “lactose intolerance (E73.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- G11 — Hereditary ataxia[Excludes2]: “metabolic disorders (E70-E88)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- G71 — Primary disorders of muscles[Excludes2]: “metabolic disorders (E70-E88)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- K90.4 — Other malabsorption due to intolerance[Excludes2]: “lactose intolerance (E73.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- N25.0 — Renal osteodystrophy[Excludes2]: “metabolic disorders classifiable to E70-E88”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- N25.81 — Secondary hyperparathyroidism of renal origin[Excludes2]: “metabolic disorders classifiable to E70-E88”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Referenced by Code First instructions
- G63 — Polyneuropathy in diseases classified elsewhere[Code First]: “metabolic diseases (E70-E88)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- H42 — Glaucoma in diseases classified elsewhere[Code First]: “specified metabolic disorder (E70-E88)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Nearest codes
- E73.0 — Congenital lactase deficiency[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- E73.1 — Secondary lactase deficiency[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- E73.8 — Other lactose intolerance[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- E73.9 — Lactose intolerance, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
Change history
- FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016
Common coding questions
Can E73 be billed directly?
No. E73 (Lactose intolerance) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.
Sources for this page
Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.
- Code, title, tabular notes and index terms Official source data
- CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
- Claim edits Official source data
- CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
- Change history and date-of-service validity Official source data
- CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
- Comparisons, relationships and the contextual map MedCoder structured relationship
- Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
- Summary and FAQ answers MedCoder explanation
- Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.
Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates
Change history
- FY2016 — October 1, 2015In the code set at ICD-10-CM adoptionLactose intolerance
No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.
Nearest Codes in This Family
Official ICD-10-CM classifications closest to E73 in its code family, with their registry titles.