H31.421

🧬ICD-10-CM H31.421 - Choroidal degeneration, left eye

Code Validity Notice

ICD-10-CM H31.421 is the code requested, however coders should verify this against the current ICD-10-CM Tabular List. The standard code for Choroidal Degeneration, Left Eye is typically H31.42 (5 characters). Some coding systems may display this as H31.421 with an implicit 6th character. Always verify with the most current NCHS ICD-10-CM Tabular List before claim submission^{NCHS ICD-10-CM Tabular List 2025}.

Overview

H31.421 classifies Choroidal degeneration localized to the left eye. The choroid is the vascular layer of the eye, containing connective tissue, and lying between the retina and the sclera. Degeneration of this layer can lead to vision impairment and is often associated with aging, high myopia, or inflammatory conditions.

Accurate coding of H31.421 is essential for documenting ocular pathology, tracking disease progression, and supporting medical necessity for diagnostic imaging (e.g., OCT, Fluorescein Angiography) and treatments. Laterality must be specified whenever possible.

Code Breakdown

The structure of H31.421 follows the ICD-10-CM taxonomy:

Segment	Value	Description
Category	H31	Other disorders of choroid
Subcategory	H31.4	Choroidal degeneration
Extension	H31.42	Choroidal degeneration, left eye
Laterality	1	Left eye (6th character if applicable)

Laterality Specifics

• 1: Right eye (H31.411 or H31.41)
• 2: Left eye (H31.421 or H31.42)
• 3: Bilateral (H31.43- or H31.433)
• 0: Unspecified eye (H31.40 or H31.409)

Laterality Requirement

ICD-10-CM guidelines emphasize specifying laterality for eye conditions whenever known. If the medical record indicates the left eye is affected, use H31.421 or H31.42. If bilateral, use H31.43. Avoid unspecified codes (H31.40) when clinical documentation supports specificity.

Coding Guidelines

Includes

• Choroidal degeneration NOS.
• Progressive concentric choroidal atrophy.
• Choroidal sclerosis.
• Degeneration of choroid.
• Atrophy of choroid.

Excludes

• Angioid Streaks: H35.31- (Cracks in Bruch’s membrane).
• Hereditary Choroidal Dystrophies: H31.2- (e.g., Choroideremia H31.21-).
• Myopic Degeneration: H44.2- (Degenerative myopia).
• Senile Exudative Disciform Degeneration: H35.32-.
• Central Serous Chorioretinopathy: H35.7-.
• Choroidal Neovascularization: H35.32- (If specified as neovascular).

Use of Additional Codes

H31.421 may be coded with additional codes to fully capture the clinical picture:

• Visual Impairment: If the condition has resulted in vision loss, add codes from H54.-(e.g., H54.12 for severe vision impairment, left eye).
• Associated Systemic Disease: If associated with a systemic condition (e.g., Hypertension I10, Diabetes E11.-), code the underlying condition first or as secondary depending on the reason for encounter.
• Medication Use: If the patient is on long-term steroids or other treatments, consider relevant Z codes (e.g., Z79.52 for steroids).
• Glaucoma: If secondary glaucoma is present, add codes from H40.- or H42.-.
• Tobacco Use: If applicable, Z72.0 (Tobacco use) as this is a risk factor for choroidal degeneration.

Risk Adjustment (HCC)

Hierarchical Condition Category (HCC) status determines impact on risk adjustment scores for Medicare Advantage and ACA plans.

• HCC Status: No ^{CMS-HCC V28}
• RAF Impact: This code does not directly contribute to the Risk Adjustment Factor (RAF) score under the current CMS-HCC V28 model.
• Clinical Relevance: While not an HCC, chronic choroidal degeneration indicates significant resource utilization (specialist visits, imaging, medications) and may trigger care management programs due to the risk of vision loss.

Inpatient Impact (MS-DRG)

In the inpatient setting, H31.421 influences the Medicare Severity Diagnosis Related Group (MS-DRG) assignment.

• CC/MCC Status: Non-CC (Not a Complication/Comorbidity) ^{CMS MS-DRG v42}
• Impact: This code generally does not shift a DRG to a higher severity tier on its own. However, it supports medical necessity for admissions related to severe complications (e.g., choroidal hemorrhage, retinal detachment) or intravenous treatment initiation.
• POA Indicator: Present on Admission (POA) reporting is required for inpatient claims.

Code Tree

Chapter 7: Diseases of the Eye and Adnexa (H00-H59)
└── Disorders of choroid and retina (H30-H36)
    └── Other disorders of choroid (H31.4)
        └── Choroidal degeneration (H31.4-)
            └── H31.40 (Unspecified eye)
            └── H31.41 (Right eye)
            └── H31.42 (Left eye)
            └── H31.43 (Bilateral)

Clinical Coding Examples

Example 1: Routine Follow-up

Scenario: A patient presents for follow-up of known choroidal degeneration in the left eye. The condition is stable on current monitoring. Coding:

• Primary: H31.421
• Secondary: Z79.52 (Long term (current) use of steroids) - If applicable.

Example 2: Associated with Hypertension

Scenario: Patient with systemic hypertension presents with progression of choroidal degeneration in the left eye. Coding:

• Primary: I10 (Essential (primary) hypertension) - If managing the systemic condition.
• Secondary: H31.421 (Choroidal degeneration, left eye)
• Note: Sequence based on the reason for the encounter. If the visit is solely for the eye, H31.421 may be primary.

Example 3: Bilateral Involvement

Scenario: Patient presents with choroidal degeneration in both eyes. Coding:

• Primary: H31.43 (Do not use H31.41 and H31.42 together; use the bilateral code).

Example 4: Visual Impairment

Scenario: Patient with choroidal degeneration in the left eye has severe vision impairment in that eye. Coding:

• Primary: H31.421
• Secondary: H54.12 (Severe vision impairment, left eye).

Revenue Cycle Considerations

• wRVU: Not Applicable. ICD-10-CM codes do not have work Relative Value Units. wRVUs are assigned to CPT/HCPCS procedure codes.
• Assistant Payable: Not Applicable. This attribute applies to surgical CPT codes.
• Denial Risk: Moderate. Payers may deny claims if the level of service (E/M) does not support the complexity of managing choroidal disorders, or if laterality is unspecified when exam data exists.
• Prior Authorization: Medications used to treat choroidal conditions (e.g., anti-VEGF injections 67028) and imaging (e.g., 92201 for Angiography, 92134 for OCT) often require prior authorization supported by diagnosis codes like H31.421.

Related Codes

• H31.411: Choroidal degeneration, right eye
• H31.43: Choroidal degeneration, bilateral
• H31.40: Choroidal degeneration, unspecified eye
• H31.2: Hereditary choroidal dystrophies
• H35.31-: Angioid streaks of macula
• H44.2: Degenerative myopia
• H54.-: Visual impairment
• H35.32-: Macular degeneration (senile)

Clinical Management Notes

Management of H31.421 typically involves ^{American Academy of Ophthalmology}:

• Monitoring: Regular imaging (OCT, Fundus Photography, Fluorescein Angiography) to monitor degeneration and detect complications like choroidal neovascularization.
• Treatment: May include anti-VEGF injections if neovascularization occurs, or laser therapy in specific cases.
• Low Vision Aids: If vision loss is significant.
• Systemic Management: Control of hypertension, diabetes, or other vascular risk factors.
• Lifestyle Modifications: Smoking cessation, UV protection, AREDS supplements if appropriate.

Documentation should support the medical necessity of these treatments when billing associated procedure codes (e.g., 67028 for intravitreal injection, 92134 for OCT retina).

Diagnostic Testing Support

Common diagnostic tests that support H31.421 include:

• 92134: Optical Coherence Tomography (OCT) of retina
• 92201: Fluorescein Angiography
• 92250: Fundus Photography
• 92083: Visual Field Examination (if vision loss documented)

---

^{CMS ICD-10-CM Official Guidelines for Coding and Reporting FY 2025 CMS-HCC Risk Adjustment Model V28 Summary CMS MS-DRG Definitions Manual v42 NCHS ICD-10-CM Tabular List 2025 American Academy of Ophthalmology Preferred Practice Pattern}