H40.112 ICD-10-CM Code: Primary open-angle glaucoma, left eye

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for H40.112 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 H40.112 itself; “inherited from” names the category or block whose note applies here.

7th Character Guide

"One of the following 7th characters is to be assigned to each code in subcategory H40.11 to designate the stage of glaucoma"

• 0 — stage unspecified
• 1 — mild stage
• 2 — moderate stage
• 3 — severe stage
• 4 — indeterminate stage

Variant codes in this family

H40.1120, H40.1121, H40.1122, H40.1123, H40.1124

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Coder workflow for H40.112

MedCoder structured workflow — derived from this code’s own official record

Before you code H40.112

1. H40.112 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).

   ReviewH40.1120, H40.1121, H40.1122, H40.1123, H40.1124

   See the relationships section · Guide: How to choose an ICD-10-CM code →

2. A 7th character is required in this family. Confirm the documentation supports the character assigned — its meaning in this family is defined in the official instruction. H40.112 is not valid without one. The official 7th-character definitions for this family are quoted in the guide.

   See the 7th Character Guide

3. Laterality is coded in this family. Confirm the side documented — right, left, or bilateral — and select the matching code (this page’s code: left). The unspecified-side code applies only when the record states no side. Laterality is assigned from the documented side; where a bilateral code exists and both sides are documented, it is used instead of two unilateral codes (Guidelines I.B.13).

   ReviewH40.111 · right, H40.113 · bilateral, H40.119 · unspecified

   Guide: Laterality coding →

4. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with H40.112. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

   See the official tabular notes

Choose the right path

1. Does the documentation support one of the more specific codes beneath H40.112?
   Yes → Select that code and continue the checks below on its own page.
   No → H40.112 cannot be reported as written; query for the specificity its subcategory needs.

   ReviewH40.1120, H40.1121, H40.1122, H40.1123, H40.1124

2. Does the documentation support a condition named in H40.112’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.

   ReviewH44.51, Q15.0, P15.3

3. Is the side documented?
   Yes → Select the code for the documented side (or the bilateral code when both sides are documented and one exists).
   No → Use the unspecified-side code only when the record states no side; a query is the alternative.

   ReviewH40.111 · right, H40.113 · bilateral, H40.119 · unspecified

4. Does the documentation support one of this family’s 7th-character values?
   Yes → Assign the matching 7th character; the variant codes are in the 7th Character Guide.
   No → The code is invalid without its 7th character — query for the missing element.

Consider H40.112. 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).

Laterality

Right, left or bilateral as documented; unspecified only when the record states no side (Guidelines I.B.13).

7th-character basis

The documented element this family’s 7th character records (see the official definitions in the 7th Character Guide).

Open or closed; displaced or nondisplaced

Defaults apply when the record is silent: closed, and displaced (Guidelines I.C.19.c).

Official instructions as workflow

• Excludes1 — check before selecting H40.112(3 notes)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with H40.112: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareH44.51, Q15.0, P15.3

  See the official tabular notes · Guidelines I.A.12.a

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

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.

Don’t confuse H40.112 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of H40.112 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• H44.51— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of absolute glaucoma moves the case to H44.51; the two are not reported together unless documented as unrelated.

  Full comparison: H40.112 vs H44.51 →

• Q15.0— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of congenital glaucoma moves the case to Q15.0; the two are not reported together unless documented as unrelated.

  Full comparison: H40.112 vs Q15.0 →

• P15.3— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of traumatic glaucoma due to birth injury moves the case to P15.3; the two are not reported together unless documented as unrelated.

  Full comparison: H40.112 vs P15.3 →

• H40.119— Specificity relationship (Review)

  Overlapping diagnoses in the same category.

  Overlapping codes in the same category — the documentation decides which is the more specific fit.

  What moves you there: A record that documents no more than “Primary open-angle glaucoma, unspecified eye” takes H40.119; specificity in the record moves it back here.

  Full comparison: H40.112 vs H40.119 →

• H40.111— Laterality relationship (Review)

  Same condition; these differ only in which side is documented.

  The same condition on the other side; the documented side decides, and a bilateral code, where one exists, replaces the pair when both sides are documented.

  What moves you there: A documented right side moves the case to H40.111.

  Full comparison: H40.112 vs H40.111 →

• H40.113— Laterality relationship (Review)

  Same condition; these differ only in which side is documented.

  The same condition on the other side; the documented side decides, and a bilateral code, where one exists, replaces the pair when both sides are documented.

  What moves you there: Documentation of both sides moves the case to H40.113.

  Full comparison: H40.112 vs H40.113 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

1. A 7th character applies in this family. Confirm the documented encounter matches the character assigned. See the official 7th-character definitions and this code’s variants
2. Laterality is coded in this family. Confirm the documented side matches the code — the opposite-side siblings are in the relationships section. See the opposite-side sibling codes
3. 3 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

• Not billable as written — a more specific code is required: H40.1120, H40.1121, H40.1122, H40.1123, H40.1124.
• Requires a 7th character. "One of the following 7th characters is to be assigned to each code in subcategory H40.11 to designate the stage of glaucoma" Options: H40.1120, H40.1121, H40.1122, H40.1123, H40.1124

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 H40.112 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 1 Excludes2 note: H25 — Age-related cataract (via H40.1.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Referenced by 1 Code First instruction: H26.23 — Glaucomatous flecks (subcapsular) (via H40.-).

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.

Referenced by 5 Use Additional Code instructions: E08.39 — Diabetes mellitus due to underlying condition with other diabetic ophthalmic complication (via H40.-), E09.39 — Drug or chemical induced diabetes mellitus with other diabetic ophthalmic complication (via H40.-), E10.39 — Type 1 diabetes mellitus with other diabetic ophthalmic complication (via H40.-), E11.39 — Type 2 diabetes mellitus with other diabetic ophthalmic complication (via H40.-), E13.39 — Other specified diabetes mellitus with other diabetic ophthalmic complication (via H40.-).

These codes instruct coders to additionally report this code when it applies.

Related Codes

Same condition, opposite side

Same category and title, differing only in which side of the body is affected.

H40.111 — Primary open-angle glaucoma, right eye (right)Compare H40.112 vs H40.111 →, H40.113 — Primary open-angle glaucoma, bilateral (bilateral)Compare H40.112 vs H40.113 →, H40.119 — Primary open-angle glaucoma, unspecified eye (unspecified)Compare H40.112 vs H40.119 →

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Glaucoma”; these codes share that main term but sit in a different category of the Tabular List.

A18.59 — Other tuberculosis of eye (tuberculous), A52.71 — Late syphilitic oculopathy (syphilitic), B73.02 — Onchocerciasis with glaucoma (in, onchocerciasis), E34.9 — Endocrine disorder, unspecified (in, endocrine disease NOS), E72.03 — Lowe's syndrome (in, Lowe's syndrome), E85.4 — Organ-limited amyloidosis (in, amyloidosis), E88.9 — Metabolic disorder, unspecified (in, metabolic disease NOS), H44.51 — Absolute glaucoma (absolute), P15.3 — Birth injury to eye (traumatic, newborn), Q13.1 — Absence of iris (in, aniridia), Q13.81 — Rieger anomaly (in, Rieger anomaly), Q15.0 — Congenital glaucoma (newborn)

Contextual Map

Every relationship of H40.112 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 H40.112 with these 7 related codes in Claim Check

Hierarchy

• H00-H59 — Chapter 7: Diseases of the Eye and Adnexa (H00-H59) (H00-H59)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H40-H42 — Glaucoma[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes2 notes

• H25 — Age-related cataract[Excludes2](via H40.1.-): “capsular glaucoma with pseudoexfoliation of lens (H40.1-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code First instructions

• H26.23 — Glaucomatous flecks (subcapsular)[Code First](via H40.-): “underlying glaucoma (H40-H42)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Use Additional Code instructions

• E08.39 — Diabetes mellitus due to underlying condition with other diabetic ophthalmic complication[Use Additional Code](via H40.-): “diabetic glaucoma (H40-H42)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• E09.39 — Drug or chemical induced diabetes mellitus with other diabetic ophthalmic complication[Use Additional Code](via H40.-): “diabetic glaucoma (H40-H42)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• E10.39 — Type 1 diabetes mellitus with other diabetic ophthalmic complication[Use Additional Code](via H40.-): “diabetic glaucoma (H40-H42)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• E11.39 — Type 2 diabetes mellitus with other diabetic ophthalmic complication[Use Additional Code](via H40.-): “diabetic glaucoma (H40-H42)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• E13.39 — Other specified diabetes mellitus with other diabetic ophthalmic complication[Use Additional Code](via H40.-): “diabetic glaucoma (H40-H42)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Nearest codes (40)

• H40 — Glaucoma[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H40.059 — Ocular hypertension, unspecified eye[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H40.06 — Primary angle closure without glaucoma damage[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H40.061 — Primary angle closure without glaucoma damage, right eye[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H40.062 — Primary angle closure without glaucoma damage, left eye[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H40.063 — Primary angle closure without glaucoma damage, bilateral[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H40.069 — Primary angle closure without glaucoma damage, unspecified eye[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• H40.1 — Open-angle glaucoma[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 32 more

Change history

• FY2017 — Added to the code set[Change history]— CMS release files (code change ledger) · icd10cm-fy2017

Common coding questions

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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to H40.112 in its code family, with their registry titles.

• H40.1110 — Primary open-angle glaucoma, right eye, stage unspecified
• H40.1111 — Primary open-angle glaucoma, right eye, mild stage
• H40.1112 — Primary open-angle glaucoma, right eye, moderate stage
• H40.1113 — Primary open-angle glaucoma, right eye, severe stage
• H40.1114 — Primary open-angle glaucoma, right eye, indeterminate stage
• H40.1120 — Primary open-angle glaucoma, left eye, stage unspecified
• H40.1121 — Primary open-angle glaucoma, left eye, mild stage
• H40.1122 — Primary open-angle glaucoma, left eye, moderate stage
• H40.1123 — Primary open-angle glaucoma, left eye, severe stage
• H40.1124 — Primary open-angle glaucoma, left eye, indeterminate stage

View all codes in the H40 family