Crystal's Coder Hub🧬 ICD-10 CM H40.1130 — Primary Open-Angle Glaucoma, Bilateral, Stage Unspecified
Billable Code Confirmed
ICD-10 CM H40.1130 is a valid, billable 8-character ICD-10-CM code for FY2026. Characters 1-3 identify the glaucoma category (H40), character 4 specifies open-angle type (1), character 5 specifies primary (1), character 6 specifies bilateral laterality (3), and the 7th-character extension (0) designates stage unspecified. All eight characters are required for valid submission; no additional characters exist below this level.
Non-Billable Parent Codes — Never Submit These
- ❌
H40— 3-character header — glaucoma category only; no type, laterality, or stage specified- ❌
H40.1— 4-character header — open-angle only; no primary/secondary, laterality, or stage- ❌
H40.11— 5-character header — primary open-angle only; no laterality or stage- ❌
H40.113— 7-character header — bilateral primary OAG; missing required stage character (7th character extension)Always submit H40.1130 (all 8 characters) when bilateral primary open-angle glaucoma is documented with stage unspecified or indeterminate by the provider.
Clinical Context: Stage Documentation Drives Code Selection — Query When Undocumented
ICD-10-CM H40.1130 captures bilateral POAG when the stage cannot be determined or has not been specified by the provider. The 7th-character extension (0 = unspecified, 1 = mild, 2 = moderate, 3 = severe, 4 = indeterminate) is assigned based on documented clinical staging, not the coder’s interpretation of IOP values or visual field data. When documentation is silent on stage, H40.1130 is appropriate — but a CDI query to the treating ophthalmologist for staging is strongly preferred to capture the most specific code and support care quality metrics.
Code Classification
ICD-10 CM Diagnosis Code — wRVU, assistant-at-surgery payable status, and global period fields are not applicable to diagnosis codes. For associated inpatient procedures, refer to the ICD-10-PCS Crosswalk section below. For profee procedure billing, refer to the Commonly Associated CPT Codes section.
🔍 Code Description
ICD-10 CM H40.1130 classifies primary open-angle glaucoma affecting both eyes, with glaucoma stage not specified. This code is used when the provider documents bilateral POAG but does not indicate — or when it cannot be determined from clinical documentation — whether the disease is in the mild, moderate, severe, or indeterminate stage.1
Primary open-angle glaucoma (POAG) is a chronic, progressive optic neuropathy characterized by open anterior chamber angles (the trabecular meshwork does not encroach on the iris base), elevated or normal intraocular pressure (IOP), and characteristic optic nerve cupping with corresponding visual field defects. The “primary” designation indicates no identifiable secondary cause such as trauma, steroid use, or uveitis. Bilateral involvement is common in POAG; however, asymmetric presentation frequently means the two eyes may be at different stages, making stage-specific documentation essential for full coding accuracy.2,3
🌳 Code Tree / Hierarchy
H40 Glaucoma ❌ Non-billable
│
├── H40.0 Glaucoma suspect and ocular hypertension ❌ Non-billable
│
├── H40.1 Open-angle glaucoma ❌ Non-billable
│ │
│ ├── H40.10 Unspecified open-angle glaucoma ❌ Non-billable
│ │ ├── H40.10X0 …stage unspecified ✅ Billable
│ │ ├── H40.10X1 …mild stage ✅ Billable
│ │ ├── H40.10X2 …moderate stage ✅ Billable
│ │ ├── H40.10X3 …severe stage ✅ Billable
│ │ └── H40.10X4 …indeterminate stage ✅ Billable
│ │
│ └── H40.11 Primary open-angle glaucoma ❌ Non-billable
│ │
│ ├── H40.111 Primary OAG, right eye ❌ Non-billable
│ │ ├── H40.1110 …stage unspecified ✅ Billable
│ │ ├── H40.1111 …mild stage ✅ Billable
│ │ ├── H40.1112 …moderate stage ✅ Billable
│ │ ├── H40.1113 …severe stage ✅ Billable
│ │ └── H40.1114 …indeterminate stage ✅ Billable
│ │
│ ├── H40.112 Primary OAG, left eye ❌ Non-billable
│ │ ├── H40.1120 …stage unspecified ✅ Billable
│ │ ├── H40.1121 …mild stage ✅ Billable
│ │ ├── H40.1122 …moderate stage ✅ Billable
│ │ ├── H40.1123 …severe stage ✅ Billable
│ │ └── H40.1124 …indeterminate stage ✅ Billable
│ │
│ └── H40.113 Primary OAG, bilateral ❌ Non-billable
│ ├── H40.1130 …stage unspecified ◀ THIS CODE ✅ Billable
│ ├── H40.1131 …mild stage ✅ Billable
│ ├── H40.1132 …moderate stage ✅ Billable
│ ├── H40.1133 …severe stage ✅ Billable
│ └── H40.1134 …indeterminate stage ✅ Billable
│
└── H40.2 Primary angle-closure glaucoma ❌ Non-billable (separate category)
Tip
Stage Unspecified ≠ Mild — Don’t Assume the Lower Stage H40.1130 (stage unspecified) and H40.1131 (mild stage) are not interchangeable. “Unspecified” means the provider has not documented a stage; “mild” requires explicit documentation of mild-stage disease based on Hodapp-Parrish-Anderson or equivalent criteria. Assigning H40.1131 without documented staging is an overcoding error. Query the provider when stage is absent from the record.
✅ Includes
The following clinical terms and scenarios map to H40.1130 when documented:
- Bilateral primary open-angle glaucoma, stage not documented or not determinable
- Bilateral chronic simple glaucoma, stage unspecified
- Bilateral normal-tension glaucoma (low-tension glaucoma), stage unspecified
- Bilateral POAG documented at first inpatient encounter without prior staging workup
- Bilateral POAG where staging criteria cannot be met due to unreliable visual field testing
❌ Excludes
Excludes 1 — Cannot Be Coded Simultaneously with H40.1130
| Code | Description | Note |
|---|---|---|
| H44.51x | Absolute glaucoma | End-stage glaucomatous blindness with no light perception; mutually exclusive — if absolute glaucoma is documented, use H44.51x (right, left, bilateral) rather than H40.1130 |
| Q15.0 | Congenital glaucoma | Buphthalmos / infantile glaucoma — developmental etiology is incompatible with primary open-angle classification; use Q15.0 alone |
| P15.3 | Traumatic glaucoma due to birth injury | Neonatal/perinatal traumatic mechanism; cannot co-exist with a primary open-angle diagnosis on the same claim |
Excludes 1 Violation Risk
The most common Excludes 1 error is attempting to code H40.1130 alongside H44.51x (absolute glaucoma) when a patient has end-stage disease in one eye and active POAG in the other. In that scenario, code each eye separately: H44.511 or H44.512 for the absolute eye, and the appropriate unilateral POAG code (H40.1110-H40.1114 or H40.1120-H40.1124) for the fellow eye.
Excludes 2 — May Be Coded in Addition if Separately Present
| Code | Description | Note |
|---|---|---|
| No Excludes 2 listed at H40.1130 level | — | Check parent-level notes at H40 and H40.1 for category-level Excludes 2 guidance |
📋 Clinical Overview
POAG Staging: The 7th-Character Extension Decision Tree
The 7th-character extension (appended to the base 7-character code H40.113_) is the most critical coding decision for this subcategory. The following comparison illustrates what each stage requires clinically and why documentation specificity matters for code selection.
| Feature | H40.1130 — Unspecified | H40.1131 — Mild | H40.1132 — Moderate | H40.1133 — Severe |
|---|---|---|---|---|
| Visual Field | Not documented / indeterminate | Abnormal VF outside central 5° | Central VF loss not threatening fixation | VF loss threatening or involving fixation |
| Optic Nerve | Not characterized by stage | Cup-to-disc enlargement, early RNFL loss | Moderate cupping, moderate RNFL loss | Advanced cupping, significant RNFL loss |
| CDI Action | Query for stage | Acceptable if explicitly documented | Acceptable if explicitly documented | Acceptable if explicitly documented |
| DRG Impact | No CC/MCC elevation | No CC/MCC elevation | No CC/MCC elevation | No CC/MCC elevation |
| Coding Priority | Use only when stage truly unknown | Always preferred over H40.1130 when documented | Always preferred over H40.1130 when documented | Always preferred over H40.1130 when documented |
Important
CDI Query Trigger — POAG Stage Missing from Inpatient Record When an inpatient record documents “bilateral primary open-angle glaucoma” without specifying a stage, and visual field reports and/or OCT results are present in the chart, query the attending ophthalmologist to document the clinical stage (mild/moderate/severe/indeterminate). Visual field and OCT data in the record cannot be used by the coder to independently assign a stage — provider documentation is required.
Common Manifestations and Associated Diagnoses
Relevant manifestations and comorbidities commonly documented with H40.1130 in the inpatient setting:
- Elevated intraocular pressure (ocular hypertension): May co-exist as a separate finding; H40.05x can be coded additionally if documented as a distinct condition
- Visual field defects: Code the defect separately if documented (e.g., H53.4x — visual field defects, including arcuate scotoma, nasal step, or generalized depression)
- Diabetic retinopathy: When POAG accompanies diabetic eye disease, code the diabetes with ophthalmic manifestation (E11.3xx series) separately — these carry significant DRG and HCC implications
- Optic nerve atrophy: H47.2x — document when present as a distinct finding beyond what is inherent to the glaucoma diagnosis
Coding Manifestations
Always code documented manifestations to fully capture the patient’s complexity. Examples include:
💰 HCC Risk Adjustment (CMS-HCC v28)
| Field | Detail |
|---|---|
| CMS-HCC Model Version | v28 (100% operative, Payment Year 2026) |
| HCC Assignment | ❌ Not HCC-Mapped |
| HCC Category | N/A |
| RAF Coefficient | N/A |
H40.1130 does not map to any HCC under CMS-HCC v28, V24, ESRD, or RxHCC models. Glaucoma codes in the H40 family were not included in v28’s 7,770 qualifying codes and do not contribute to a patient’s risk adjustment factor (RAF) score.
Not HCC-Captured — Focus Shifts to Associated Comorbidities
Because H40.1130 carries no RAF value, ensure that all other documented conditions with HCC-mapping potential are captured fully. In glaucoma patients, the most important associated HCC-mapped codes include diabetes with ophthalmic complications (E11.311-E11.359 series → HCC 18/19/37 depending on specificity) and any neurological comorbidities. Annual HCC capture requirements do not apply to H40.1130 itself.
🏥 MS-DRG Assignment
MDC 02 — Diseases and Disorders of the Eye
| DRG | Title | Est. Relative Weight* |
|---|---|---|
| DRG 124 | Other Disorders of the Eye with MCC or Thrombolytic Agent | ~1.30 - 1.60 |
| DRG 125 | Other Disorders of the Eye without MCC | ~0.60 - 0.80 |
| Approximate. Verify against IPPS FY2026 Final Rule Table 5 (CMS.gov). Note: DRGs 124/125 are a 2-way split — there is no separate CC tier for this grouping. |
2-Way Split — No CC Tier Exists
Unlike many MDC groupings that split three ways (with MCC / with CC / without CC/MCC), the Other Disorders of the Eye DRG pair splits only on MCC presence. H40.1130 itself is not a CC or MCC designator; it carries no DRG-elevating weight when used as a secondary diagnosis under a different MDC principal diagnosis. When H40.1130 is the principal diagnosis driving MDC 02, the only DRG lever available is whether a qualifying MCC (such as acute respiratory failure, severe sepsis, or hepatic failure) is present as a secondary diagnosis. Accurate and complete secondary diagnosis capture is therefore critical to achieving DRG 124 when clinically warranted.
🔗 Related ICD-10-CM Codes
Laterality and Staging Variants — Primary Open-Angle Glaucoma (H40.113x Family)
| Code | Description |
|---|---|
| H40.1130 | Primary OAG, bilateral, stage unspecified ← This Code |
| H40.1131 | Primary OAG, bilateral, mild stage |
| H40.1132 | Primary OAG, bilateral, moderate stage |
| H40.1133 | Primary OAG, bilateral, severe stage |
| H40.1134 | Primary OAG, bilateral, indeterminate stage |
Unilateral and Unspecified Laterality Variants
| Code | Description |
|---|---|
| H40.1110 | Primary OAG, right eye, stage unspecified |
| H40.1120 | Primary OAG, left eye, stage unspecified |
| H40.10X0 | Unspecified open-angle glaucoma, stage unspecified |
Clinically Related Glaucoma Categories
| Code | Description |
|---|---|
| H40.20x0 | Unspecified primary angle-closure glaucoma, stage unspecified (mechanistically distinct) |
| H40.051 | Ocular hypertension, right eye (frequently co-documented with POAG) |
| H40.052 | Ocular hypertension, left eye |
| H40.053 | Ocular hypertension, bilateral |
| H44.511 | Absolute glaucoma, right eye (end-stage; Excludes 1 with H40.1130 for same eye) |
| H44.512 | Absolute glaucoma, left eye |
| H44.513 | Absolute glaucoma, bilateral |
| Z98.83 | Filtering (vitreous) bleb after glaucoma surgery status |
🛠️ Commonly Associated CPT Codes (Ophthalmology — Inpatient and Profee)
Inpatient Setting Context
When bilateral POAG (H40.1130) drives an inpatient admission — most commonly for surgical glaucoma intervention — the inpatient facility uses ICD-10-PCS for procedure coding. The CPT codes below are relevant for profee (physician professional fee) billing by the operating or managing ophthalmologist during or following the inpatient encounter. Laterality modifiers -RT and -LT are required on all unilateral procedure codes; when both eyes are treated in the same operative session, report each eye separately with appropriate modifiers.
| CPT Code | Description | Profee Coding Notes |
|---|---|---|
| 66170 | Trabeculectomy ab externo, no prior surgery | 90-day global; report per eye with -RT/-LT; most common inpatient glaucoma surgery for POAG |
| 66172 | Trabeculectomy ab externo, with scarring from prior surgery | 90-day global; use when prior ocular surgery has created significant conjunctival/scleral scarring |
| 66179 | Aqueous shunt to extraocular equatorial plate reservoir, without graft | 90-day global; for tube shunt placement (e.g., Ahmed, Baerveldt); report per eye |
| 66180 | Aqueous shunt to extraocular equatorial plate reservoir, with graft | 90-day global; scleral patch graft included in code descriptor |
| 66183 | Anterior segment aqueous drainage device, without extraocular reservoir (e.g., Ex-PRESS mini shunt) | 90-day global; report regardless of prior surgery status |
| 65855 | Trabeculoplasty by laser surgery | 90-day global; selective laser trabeculoplasty (SLT) — typically outpatient; link to H40.1130 |
| 92083 | Visual field examination, extended | No global; paired with H40.1130 to document POAG staging and progression monitoring |
| 92133 | Scanning computerized ophthalmic diagnostic imaging (OCT), optic nerve | No global; essential for RNFL thickness tracking in POAG management |
NCCI Bundling Considerations
- Trabeculectomy (66170 or 66172) performed bilaterally in a single session: report each eye separately using -RT and -LT; modifier -51 (multiple procedures) may apply per payer; confirm bilateral same-session policy with payer prior to submission.
- Visual field testing (92083) and OCT (92133) billed on the same day as a surgical glaucoma procedure (66170, 66179, 66183) are bundled into the procedure’s global period unless a separately identifiable medical decision-making service is documented — modifier -25 on the E/M code and/or modifier -59 on the diagnostic service may be required.
- Laser trabeculoplasty (65855) billed on the same day as an E/M service requires modifier -25 on the E/M to confirm a separately identifiable evaluation was performed.
🔬 ICD-10-PCS Crosswalk (Inpatient Procedures)
When H40.1130 is an inpatient principal or secondary diagnosis, these ICD-10-PCS codes are relevant for associated inpatient surgical procedures.
| PCS Section | Body System | Root Operation | Clinical Application |
|---|---|---|---|
| 0 (Medical & Surgical) | 8 (Eye) | 1 (Bypass) | Trabeculectomy ab externo: aqueous humor is redirected from the anterior chamber to the subconjunctival space, creating a filtering bleb. Right eye: 081130Z (Bypass anterior chamber, right, percutaneous, no device/qualifier). Left eye: 082130Z. Note: PCS classifies trabeculectomy as Bypass, not Excision, because the functional objective is rerouting aqueous flow. |
| 0 (Medical & Surgical) | 8 (Eye) | H (Insertion) | Aqueous drainage device (tube shunt) implantation: a synthetic drainage tube is inserted into the anterior chamber and routed to an equatorial plate. Right eye example with synthetic substitute: 08H13YZ. Left eye: 08H23YZ. Device character Y = Other Device captures the tube-plate shunt assembly. |
| 0 (Medical & Surgical) | 8 (Eye) | C (Extirpation) | Goniotomy / trabeculotomy ab interno: excision of trabecular meshwork tissue to improve aqueous outflow. Right eye percutaneous: 08C13ZZ. Left eye: 08C23ZZ. Used for MIGS procedures performed inpatient. |
| 8 (Other Procedures) | E (Physiological Systems) | 0 (Other Procedures) | Laser trabeculoplasty performed in the inpatient setting (rare): coded under Section 8 Other Procedures if no better-fitting Medical & Surgical root operation applies. |
💊 Coding Scenarios and Examples
Scenario 1 — Inpatient: Bilateral POAG Admission for Staged Bilateral Tube Shunt Surgery
Clinical Vignette: A 74-year-old male with long-standing bilateral POAG presents for elective inpatient admission for right eye Ahmed glaucoma valve implantation. IOP has been uncontrolled at 28 mmHg OD and 24 mmHg OS despite maximum topical therapy. The ophthalmologist documents “primary open-angle glaucoma, bilateral” in the admitting H&P but does not specify a glaucoma stage. Comorbidities include type 2 diabetes with diabetic macular edema and controlled hypertension.
Principal Diagnosis:
- H40.1130 — Primary OAG, bilateral, stage unspecified (Reason for admission — glaucoma surgery)
Secondary Diagnoses:
- E11.311 — Type 2 diabetes with mild nonproliferative diabetic retinopathy with macular edema, right eye (comorbidity; HCC-mapped — capture carefully)
- I10 — Essential (primary) hypertension (comorbidity)
ICD-10-PCS Procedure:
- 08H13YZ — Insertion of other device into anterior chamber, right eye, percutaneous approach (Ahmed valve implant, right eye)
MS-DRG Assignment: Absent a qualifying MCC secondary diagnosis → DRG 125. If the diabetes documentation were escalated to severe NPDR or proliferative retinopathy with additional systemic complications meeting MCC criteria, DRG 124 could be triggered — review all secondary diagnoses carefully.
Scenario 2 — Inpatient: POAG as Secondary Diagnosis with MCC-Driving Primary Admission
Clinical Vignette: A 68-year-old female is admitted to an inpatient ophthalmology service following acute bacterial endophthalmitis of the right eye post-cataract surgery. Past medical history is significant for bilateral primary open-angle glaucoma documented on the ophthalmologist’s problem list. The inpatient record does not contain glaucoma staging documentation, IOP measurements, or visual field results for the current admission.
Principal Diagnosis:
- H44.011 — Acute endophthalmitis, right eye (Reason for admission)
Secondary Diagnoses:
- H40.1130 — Primary OAG, bilateral, stage unspecified (chronic comorbidity; not a CC/MCC — does not affect DRG split)
- Z98.4 — Cataract extraction status (surgical history relevant to context)
MS-DRG Assignment: Endophthalmitis with CC/MCC would route through DRG 121 (Acute Major Eye Infections with CC or MCC) or DRG 122 (without CC or MCC). H40.1130 as a secondary diagnosis does not affect DRG grouping.
Scenario 3 — CDI Query: Glaucoma Stage Not Documented
Clinical Vignette: A 71-year-old female is admitted for elective bilateral trabeculectomy for medically refractory primary open-angle glaucoma. The admitting diagnosis reads: “POAG bilateral, uncontrolled.” Visual field reports in the chart show central field sparing with a superior arcuate defect in the right eye and a nasal step in the left eye — findings consistent with moderate-stage disease. The discharge summary does not specify glaucoma stage.
Action / Outcome: The admitting record contains clinical data (Humphrey visual field results) that may support moderate-stage POAG (H40.1132), but coders cannot independently interpret diagnostic test results to assign a stage — that determination requires provider documentation. A compliant CDI query should be sent to the attending ophthalmologist requesting that the glaucoma stage be documented per clinical findings.
Query Response: Provider updates the discharge summary: “Bilateral primary open-angle glaucoma, moderate stage (Humphrey VF: superior arcuate OD, nasal step OS — central field preserved bilaterally).”
Corrected ICD-10-CM Coding:
- H40.1132 — Primary OAG, bilateral, moderate stage (replaces H40.1130 after CDI clarification)
- 66170-RT and 66170-LT — Trabeculectomy ab externo, each eye (profee codes)
⚠️ Coding Pitfalls and Tips
| Pitfall or Tip | |
|---|---|
| ❌ | Submitting the 7-character parent code H40.113. The trailing digit (7th-character extension for stage) is mandatory — H40.113 without the stage character is not a valid billable code and will reject. Always report the full 8-character code H40.1130 through H40.1134. |
| ❌ | Using H40.1130 when a stage is actually documented. Stage-unspecified codes are the coding fallback, not the default. If the ophthalmologist has documented “mild,” “moderate,” “severe,” or “indeterminate,” assign the corresponding specific code (H40.1131-H40.1134). Using H40.1130 when a stage is documented constitutes undercoding. |
| ❌ | Coding H40.1130 and H44.51x simultaneously for the same eye. Absolute glaucoma (H44.51x) carries an Excludes 1 with H40.1130. If one eye has progressed to absolute glaucoma, use the laterality-specific absolute glaucoma code for that eye and the appropriate unilateral POAG code for the fellow eye. |
| ✅ | Query for stage when any glaucoma workup data exists in the chart. Visual field reports, OCT RNFL scans, and optic nerve photos document staging criteria — when these are present but the provider has not explicitly staged the disease, a CDI query is warranted. Staging elevates coding specificity, supports quality metrics, and may capture additional clinically relevant information. |
| ✅ | Capture all associated eye comorbidities separately. Diabetic retinopathy, optic atrophy, ocular hypertension, and visual field defects are separately codeable conditions that contribute to accurate severity capture and, in the case of diabetes-related eye disease, HCC risk-adjustment value. Do not assume they are bundled into H40.1130. |
| ✅ | Apply -RT / -LT modifiers on all profee procedure codes. Even when H40.1130 reflects bilateral disease, CPT glaucoma surgery codes (66170, 66179, 66183, etc.) are reported per-eye with laterality modifiers. Bilateral procedure on the same date = two line items with -RT and -LT respectively. |
📚 Sources
- CMS/NCHS. ICD-10-CM Official Guidelines for Coding and Reporting, FY2026. Section I.C.7 — Diseases of the Eye and Adnexa; glaucoma 7th-character staging instructions.
- American Academy of Ophthalmology. Preferred Practice Pattern: Primary Open-Angle Glaucoma. San Francisco: AAO; 2020 (updated 2022).
- Weinreb RN, Aung T, Medeiros FA. The pathophysiology and treatment of glaucoma: a review. JAMA. 2014;311(18):1901-1911.
- CMS. ICD-10-CM/PCS MS-DRG v43.0 Definitions Manual — MDC 02, Other Disorders of the Eye. Effective FY2026 (October 1, 2025-September 30, 2026).
- CMS. IPPS Final Rule FY2026 — MS-DRG Relative Weights, Table 5. Federal Register, August 4, 2025 (90 FR 64000 et seq.). MDC 02 DRG 124-125 logic tables.
- CMS. 2026 Medicare Advantage Risk Adjustment — CMS-HCC Model v28 ICD-10-CM Mappings. H40.x codes confirmed not mapped; v28 fully operative January 1, 2026.
- AMA. CPT Professional Edition 2026. Surgery — Eye and Ocular Adnexa, codes 65855, 66170-66185.
- Kuehn L. “Coding Trabeculectomy for Glaucoma.” Libman Education — Coders’ Corner. Updated November 2024. (ICD-10-PCS Bypass root operation rationale for trabeculectomy.)