What is ICD-10 code H40.159?

H40.159 is the ICD-10-CM diagnosis code for Residual stage of open-angle glaucoma, unspecified eye. The final stage of open-angle glaucoma in an eye where the specific side (right or left) is not documented or is unclear. H40.159 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. H40.159 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. H40.159 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. H40.159 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for H40.159?

H40.159 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards H40.159 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

What should coders know when reporting H40.159?

Use this code only when the eye laterality cannot be determined from the medical record Query the provider if possible to determine which eye is affected for more specific coding

H40.159: Residual stage of open-angle glaucoma, unspecified eye — ICD-10

ICD-10-CM Code View

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Code lookupH40.159Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the eye and adnexa (H00-H59) / Glaucoma (H40-H42)

H40.159

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Residual stage of open-angle glaucoma, unspecified eye

The final stage of open-angle glaucoma in an eye where the specific side (right or left) is not documented or is unclear.

Buddy Insight

Residual stage of open-angle glaucoma, unspecified eye is used when residual glaucoma damage is documented but the laterality is not specified.

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Not risk-adjusted for this model/period.

RAF 0

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Not risk-adjusted for this model/period.

RAF 0

RXHCC

Mapped

HCC 243

Glaucoma

RAF 0.0

Code Trumping

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Code Book Path

Official

H40.1Open-angle glaucoma

H40.15Residual stage of open-angle glaucoma

H40.159Residual stage of open-angle glaucoma, unspecified eye

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for H40.159 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for H40.159 in this effective period.

Related Child Codes

Official

H40.151Residual stage of open-angle glaucoma, right eye

H40.152Residual stage of open-angle glaucoma, left eye

H40.153Residual stage of open-angle glaucoma, bilateral

Includes

Official

ICD-10-CM does not list Includes notes for H40.159 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for H40.159 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for H40.159 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for H40.159 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for H40.159 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation of residual stage open-angle glaucoma without laterality specification

Evidence of prior glaucoma with current arrested disease state

Documentation of residual optic nerve damage or visual field loss

Query to the examining ophthalmologist for laterality clarification

MEAT Support

HCC Buddy guidance

Documentation of residual stage open-angle glaucoma without laterality specification

Evidence of prior glaucoma with current arrested disease state

Documentation of residual optic nerve damage or visual field loss

Query to the examining ophthalmologist for laterality clarification

Audit Caution

HCC Buddy guidance

Using this code when laterality information exists in the ophthalmic record

Not querying the ophthalmologist for laterality specification

Confusing residual stage with other stages of active glaucoma

Using this code for convenience rather than pursuing documentation specificity

Common Mistakes

HCC Buddy guidance

H40.151-H40.153 — Laterality-specific residual stage open-angle glaucoma: always preferred when laterality documented

H40.10X0 — Unspecified open-angle glaucoma, unspecified eye: does not specify residual stage

H40.9 — Unspecified glaucoma: even less specific, does not capture open-angle type or stage

H40.239 — Intermittent angle-closure glaucoma, unspecified eye: different type of glaucoma

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is H40.159 an HCC code?

No. H40.159 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

HCC Category Mapping

RxHCCHCC 243, Glaucoma

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work H40.159 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for H40.159

For H40.159to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed H40.159 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

H40.159 is the ICD-10-CM diagnosis code for residual stage of open-angle glaucoma, unspecified eye. The final stage of open-angle glaucoma in an eye where the specific side (right or left) is not documented or is unclear. H40.159 sits in the ICD-10-CM chapter for diseases of the eye and adnexa (h00-h59), within the section covering glaucoma (h40-h42).

H40.159 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

This code does not map to a CMS-HCC V28 payment category. Capture depends on documentation that supports the diagnosis; verify the HCC assignment against the current CMS mapping for the applicable payment year. Coders reviewing H40.159 should check whether additional documentation would support a more specific child code in the same hierarchy that does map to a payment HCC, capturing the correct specificity is the highest-impact RAF improvement available within accurate coding.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for H40.159 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use this code only when the eye laterality cannot be determined from the medical record
•Query the provider if possible to determine which eye is affected for more specific coding

Clinical Significance

Residual stage of open-angle glaucoma, unspecified eye is used when residual glaucoma damage is documented but the laterality is not specified. This code should be avoided when possible since ophthalmic examinations routinely document laterality. It represents a documentation quality issue that should be addressed through provider query or record review.

Documentation Requirements

✓Documentation of residual stage open-angle glaucoma without laterality specification
✓Evidence of prior glaucoma with current arrested disease state
✓Documentation of residual optic nerve damage or visual field loss
✓Query to the examining ophthalmologist for laterality clarification
✓Treatment and monitoring plan

Commonly Confused Codes

•H40.151-H40.153: Laterality-specific residual stage open-angle glaucoma: always preferred when laterality documented
•H40.10X0: Unspecified open-angle glaucoma, unspecified eye: does not specify residual stage
•H40.9: Unspecified glaucoma: even less specific, does not capture open-angle type or stage
•H40.239: Intermittent angle-closure glaucoma, unspecified eye: different type of glaucoma