🧬 ICD-10 CM H40.052 — Ocular Hypertension, Left Eye
Billable Code Confirmed
ICD-10-CM H40.052 is a fully specified 6-character code — three characters for the category (H40), one for the subcategory (.0), and two for the laterality/eye digit (5, 2) — so it carries no billable warning. It is used when intraocular pressure is measured above the normal range in the left eye but the optic nerve and visual field remain intact.
Clinical Context
Selection of H40.052 over its parent or siblings depends entirely on which eye is elevated and whether glaucomatous damage has occurred; documentation must specify laterality (right, left, or bilateral) and confirm absence of optic nerve cupping or visual field defect to justify this “suspect” category code rather than a true glaucoma code.
Code Classification
ICD-10 CM H40.052 is a diagnosis code (not a procedure code) found in ICD-10-CM Chapter 7, used to report a clinical finding of elevated intraocular pressure that has not yet progressed to structural or functional glaucomatous change.
🔍 Code Description
Ocular hypertension refers to intraocular pressure (IOP) that is measured above the statistically normal range — generally above 21 mmHg — without accompanying optic nerve cupping, glaucomatous visual field loss, or other structural damage. H40.052 specifically documents this finding as isolated to the left eye, distinguishing it from H40.051 (right eye involvement) and H40.053 (bilateral involvement) when pressure elevation affects both eyes simultaneously. Because ocular hypertension is a risk factor for future glaucoma rather than glaucoma itself, it sits in the “glaucoma suspect” family under category H40.0- rather than under the true open-angle or angle-closure glaucoma codes.
Clinically, patients coded with H40.052 are typically monitored with serial tonometry, gonioscopy, and periodic visual field testing to detect any conversion toward manifest glaucoma. If glaucomatous damage is later confirmed in the left eye, the coder must transition to an appropriate active glaucoma code such as unspecified open-angle glaucoma, left eye, rather than continuing to report H40.052. Because this is a suspect/monitoring code, documentation should explicitly state “no glaucomatous optic nerve damage” or “no visual field loss” to support ongoing use of this classification instead of a definitive glaucoma diagnosis.
🌳 Code Tree / Hierarchy
H40 Glaucoma ❌ Non-billable (category header)
│
├── H40.0 Glaucoma suspect ❌ Non-billable
│ │
│ ├── H40.00 Preglaucoma, unspecified ❌ Non-billable
│ ├── H40.01 Open angle with borderline findings, low risk ❌ Non-billable
│ ├── H40.03 Anatomical narrow angle ❌ Non-billable
│ ├── H40.04 Steroid responder ❌ Non-billable
│ │
│ ├── H40.05 Ocular hypertension ❌ Non-billable
│ │ │
│ │ ├── H40.051 Ocular hypertension, right eye ✅ Billable
│ │ ├── H40.052 Ocular hypertension, left eye ◀ THIS CODE ✅ Billable
│ │ ├── H40.053 Ocular hypertension, bilateral ✅ Billable
│ │ └── H40.059 Ocular hypertension, unspecified eye ✅ Billable
│ │
│ └── H40.06 Primary angle closure suspect ❌ Non-billable
│
└── H40.1 Open-angle glaucoma ❌ Non-billable (category header)Laterality Drives Code Selection
Payers expect the most specific laterality supported by documentation; reporting H40.059 (unspecified eye) when the chart clearly identifies “left eye” elevated pressure is a common audit flag and may trigger payer queries or denials.
Tip
ICD-10 CM H40.052 requires no 7th-character extension and no additional laterality digit beyond the sixth character — it is complete as written and should never be truncated to H40.05-.
✅ Includes
- Elevated intraocular pressure, left eye, without optic nerve damage or visual field loss — this describes a measured IOP above the normal threshold with a structurally and functionally healthy optic nerve confirmed on exam.
- Borderline intraocular pressure, left eye — used when serial readings hover near the upper limit of normal without meeting a definitive elevated threshold on every measurement.
- Ocular hypertension, OS (oculus sinister) — the standard ophthalmic shorthand notation coders will frequently see charted for this exact clinical picture.
❌ Excludes
Excludes 1
- H44.51- Absolute glaucoma — describes a blind, painful eye from end-stage glaucoma; this is mutually exclusive with H40.052 because absolute glaucoma represents a completely different, far more advanced disease state than a suspect finding of elevated pressure alone.
- Q15.0 Congenital glaucoma (buphthalmos) — a developmental anomaly present at or near birth, coded in the congenital malformations chapter rather than the acquired glaucoma family, so it cannot be reported alongside H40.052 for the same eye.
- P15.3 Traumatic glaucoma due to birth injury — a perinatal trauma code that is inherently incompatible with a “suspect, no damage yet” ocular hypertension code.
Danger
The most common Excludes 1 error is reporting H40.052 concurrently with H44.51-, Q15.0, or P15.3 for the same eye and encounter. Because Excludes1 means “not coded here,” claims with both a glaucoma-suspect code and one of these definitively damaged/congenital codes for the same eye risk automated payer rejection; verify which condition is actually present before finalizing code selection.
Excludes 2
None identified for H40.052 at the FY2026 code level; no additional conditions are separately reportable alongside this code beyond standard comorbidity documentation.
📋 Clinical Overview
Ocular Hypertension vs. Glaucoma Suspect Subtypes
ICD-10 CM H40.052 sits alongside several other “glaucoma suspect” subtypes that share the H40.0 category but represent distinct clinical presentations. Understanding the difference prevents miscoding a patient with borderline optic nerve findings as simple ocular hypertension, or vice versa.
| Feature | H40.052 | Related H40.02 (Open angle, borderline findings, high risk) | Related H40.06 (Primary angle closure suspect) |
|---|---|---|---|
| Primary finding | Elevated IOP only, left eye | Suspicious optic disc/visual field findings, no confirmed glaucoma | Anatomically narrow angle at risk for acute closure |
| Optic nerve status | Normal, no cupping | Borderline/equivocal cupping | Typically normal until an acute angle-closure event |
| Typical management | Serial tonometry, IOP-lowering drops if risk factors present | Closer monitoring, repeat visual fields/imaging | Gonioscopy, prophylactic laser iridotomy consideration |
Important
CDI teams should query when documentation says only “elevated eye pressure” without laterality — H40.052 cannot be assigned to a chart lacking a specific left-eye reference, and defaulting to the unspecified-eye code (H40.059) loses coding precision that payers and quality programs increasingly scrutinize.
Manifestations & Symptom Burden
- Asymptomatic in the vast majority of cases — most patients are identified incidentally during routine tonometry at a comprehensive eye exam.
- Mild eye ache or transient blurred vision may occur if IOP is significantly elevated, though this is uncommon at borderline levels.
- No visual field defect or optic disc cupping should be present; if either appears, the diagnosis is no longer ocular hypertension and requires reclassification to a manifest glaucoma code.
Tip
Because ocular hypertension is defined by the absence of damage, any new visual field abnormality documented at a follow-up visit should prompt an immediate code change away from H40.052 rather than continued use.
💰 HCC Risk Adjustment
Ocular hypertension does not map to any CMS-HCC V28 payment category for payment year 2026.[^1] It is treated as a low-acuity, monitorable finding rather than a chronic condition with material cost implications, so capturing H40.052 has no RAF-score effect and should never be prioritized purely for risk-adjustment purposes — its clinical value lies in supporting medical necessity for ongoing IOP monitoring services, not in value-based payment capture.
🏥 MS-DRG Assignment
ICD-10 CM H40.052 groups to MDC 02 (Diseases & Disorders of the Eye). If reported as the principal diagnosis on an inpatient claim, it would assign to DRG 124 (Other Disorders of the Eye With MCC) or DRG 125 (Other Disorders of the Eye Without MCC) depending on the presence of a qualifying major complication/comorbidity.[^2] In real-world practice, ocular hypertension is coded almost exclusively in outpatient ophthalmology and optometry encounters, so inpatient DRG assignment for this code alone is rare and usually only occurs when it’s a secondary diagnosis on a stay driven by an unrelated MCC.
NCD/LCD considerations: There is no NCD written specifically for H40.052, but multiple Medicare Administrative Contractor LCDs covering ophthalmic diagnostic testing — extended ophthalmoscopy, visual field examination (92081–92083), scanning computerized ophthalmic diagnostic imaging posterior segment (92133), gonioscopy (92020), and serial tonometry (92100) — list H40.051/H40.052/H40.053/H40.059 among covered supporting diagnoses.[^3] Additionally, be aware that Medicare’s separate glaucoma-screening NCD (§80.11) uses screening code Z13.5 with G0117/G0118, not H40.052, since a confirmed ocular hypertension diagnosis moves the encounter out of “screening” status.[
🔗 Related ICD-10-CM Codes
Ocular hypertension family (siblings):
- H40.051 — Ocular hypertension, right eye
- H40.053 — Ocular hypertension, bilateral
- H40.059 — Ocular hypertension, unspecified eye
Other glaucoma-suspect and related diagnoses:
- H40.01 — Open angle with borderline findings, low risk (laterality-specific codes)
- H40.02 — Open angle with borderline findings, high risk (laterality-specific codes)
- H40.03 — Anatomical narrow angle (laterality-specific codes)
- H40.04 — Steroid responder (laterality-specific codes)
- H40.06 — Primary angle closure suspect (laterality-specific codes)
- H40.11 — Primary open-angle glaucoma, if the patient later converts (laterality/stage-specific codes)
🛠️ Commonly Associated CPT Codes
- 92100 — Serial tonometry with multiple IOP measurements over an extended period; supports monitoring diurnal IOP fluctuation in a confirmed ocular hypertension patient and requires at least three timed pressure readings documented in the note.
- 92020 — Gonioscopy; used to assess the anterior chamber angle and rule out an angle-closure component contributing to the elevated pressure.
- 92083 — Visual field examination, extended; establishes a baseline and monitors for any emerging field loss that would reclassify the patient out of the ocular hypertension code.
- 92133 — Scanning computerized ophthalmic diagnostic imaging, posterior segment, optic nerve; used to document a structurally normal optic nerve, supporting continued use of H40.052 rather than a manifest glaucoma code.
- 92012 — Established patient ophthalmological exam, intermediate; the routine office visit at which IOP is typically measured and monitored.
- 92014 — Established patient ophthalmological exam, comprehensive; used for a more complete periodic evaluation of a monitored ocular hypertension patient.
🏷️ Modifier Reference
| Modifier | Name | When to Apply |
|---|---|---|
| -LT | Left Side | Append to CPT codes such as 92100 or 92133 when the service is performed only on the left eye to match the H40.052 laterality. |
| -RT | Right Side | Not applicable to a left-eye-only H40.052 encounter, but relevant if the right eye is separately tested and billed the same day for a different condition. |
| -50 | Bilateral | Not applicable when only the left eye is being tested for this diagnosis; use only if both eyes are tested and billed as bilateral under a code that permits it. |
| -25 | Significant, Separately Identifiable E/M | Applies when a significant, separately identifiable E/M service is performed the same day as a diagnostic test like tonometry or visual field testing. |
| -59 | Distinct Procedural Service | Applies when two normally bundled diagnostic tests (e.g., gonioscopy and visual field testing) are performed for genuinely distinct clinical reasons on the same date. |
NCCI Bundling Considerations
Routine, single-measurement tonometry is bundled into the general ophthalmological exam codes and should not be billed separately; only serial tonometry (92100) with multiple timed measurements and documented interpretation supports separate reimbursement alongside an eye exam.[
💊 Coding Scenarios and Examples
Example 1
Clinical Scenario: An established patient presents for a comprehensive eye exam. IOP is measured at 24 mmHg in the left eye and 16 mmHg in the right eye. Optic disc appears healthy bilaterally with no cupping, and prior visual fields are normal. The physician documents “ocular hypertension, left eye, continue monitoring.”
| Field | Code | Rationale |
|---|---|---|
| CPT | 92014 | Comprehensive established-patient eye exam supports the IOP measurement and clinical assessment. |
| PDx | H40.052 | Confirmed left-eye elevated IOP without optic nerve damage matches the code definition exactly. |
Tip
No modifier is needed since the comprehensive exam code inherently covers bilateral assessment; document laterality clearly in the note to justify H40.052 over the bilateral or unspecified-eye variants.
Example 2
Clinical Scenario: A patient with known left-eye ocular hypertension returns for serial tonometry to evaluate diurnal IOP variation, with three pressure readings taken across the day, followed by a brief discussion of treatment adjustment during the same visit.
| Field | Code | Rationale |
|---|---|---|
| CPT | 92100-LT | Serial tonometry with the left-side modifier confirms the test was performed specifically on the affected eye. |
| CPT 2 | 99213-25 | A significant, separately identifiable E/M service for treatment discussion supports billing both the test and the visit. |
| PDx | H40.052 | Diagnosis driving medical necessity for the serial tonometry and follow-up visit. |
Tip
Modifier -25 is essential here to unbundle the E/M visit from the diagnostic testing; without it, many payers will deny the E/M as included in the procedure.
Example 3
Clinical Scenario: A patient previously coded with ocular hypertension, left eye, is found on follow-up visual field testing to have a new superior arcuate defect in the left eye, prompting the ophthalmologist to diagnose early primary open-angle glaucoma, left eye.
| Field | Code | Rationale |
|---|---|---|
| CPT | 92083 | Extended visual field exam identified the new defect prompting the diagnosis change. |
| PDx | H40.1121 | Once glaucomatous damage is confirmed, the diagnosis must shift to a mild-stage open-angle glaucoma code, left eye; H40.052 is no longer accurate and must be discontinued. |
Tip
This scenario illustrates why ocular hypertension is a transitional, not permanent, diagnosis — any confirmed structural or functional change requires immediate reclassification away from H40.052.
⚠️ Coding Pitfalls and Tips
- Pitfall 1: Continuing to report H40.052 indefinitely after glaucomatous damage develops, rather than transitioning to a manifest glaucoma code once visual field loss or optic nerve cupping is confirmed. Tips: Review visual field and imaging results at every visit and update the diagnosis the moment damage is documented.
- Pitfall 2: Defaulting to H40.059 (unspecified eye) when the chart clearly states “left eye,” losing coding specificity that some payers and quality programs flag. Tips: Always cross-reference laterality documentation in the exam note before finalizing the sixth character.
- Pitfall 3: Billing single-measurement tonometry separately when it should be bundled into the E/M or eye exam code; only serial tonometry (92100) with multiple timed readings supports separate billing. Tips: Confirm at least two to three distinct, timed IOP measurements are documented before assigning 92100.
- Pitfall 4: Reporting H40.052 alongside an Excludes1 code such as H44.51- for the same eye and encounter, triggering an automated payer edit rejection. Tips: Confirm the patient’s actual disease stage before code selection — ocular hypertension and absolute glaucoma cannot coexist for the same eye.
- Pitfall 5: Omitting modifier -LT on unilateral diagnostic tests like 92133 or 92100, causing claims processing confusion about which eye was actually tested. Tips: Append laterality modifiers consistently whenever a CPT code doesn’t inherently specify eye side.
- Pitfall 6: Treating ocular hypertension as an HCC-capturable chronic condition for risk-adjustment purposes. Tips: Recognize this code carries no RAF weight under CMS-HCC V28 and code it strictly for clinical accuracy and medical-necessity support, not risk-score optimization.
📚 Sources
1. Centers for Medicare & Medicaid Services. *2026 CMS-HCC Model Software and ICD-10-CM Mappings.* CMS; 2025-2026. cms.gov/medicare/payment/medicare-advantage-rates-statistics/risk-adjustment/2026-model-software-icd-10-mappings 2. Centers for Medicare & Medicaid Services. *ICD-10-CM/PCS MS-DRG v37.2 Definitions Manual, MDC 02 — Diseases & Disorders of the Eye (DRG 124–125).* CMS; 2025. 3. American Academy of Ophthalmology. *Testing Services, Part Three & Four: Tests Performed by Physicians/Staff.* AAO EyeNet; 2012. Envolve Vision. *Serial Tonometry Clinical Policy OC.UM.CP.0074.* 2024. AAPC. *ICD-10-CM Code Lookup: H40.05, H40.051, H40.052, H40.053, H40.059, H44.51, Q15.0, P15.3.* aapc.com/codes/icd-10-codes/Sources listed above correspond to superscript citations throughout this note. Verify all Medicare payment figures against your current CMS PFS Lookup tool and applicable MAC LCD prior to claim submission. Please use the latest AAPC/AHIMA coding books to verify each code within this note.