Crystal's MCW Coder Hub🧬 ICD-10-CM H11.003 — Unspecified Pterygium of Eye, Bilateral
Quick Reference
Code: H11.003 | Billable: Yes | Chapter: 7 — Eye and Adnexa | HCC: No | Laterality: Bilateral | Type: Unspecified (specific subtype not documented for either eye)
Description
ICD-10-CM H11.003 identifies a pterygium affecting both eyes where the specific subtype has not been documented by the treating provider for either eye. A pterygium (from the Greek pterygion, meaning “little wing”) is a fibrovascular growth of bulbar conjunctival tissue that encroaches onto the corneal surface — most commonly arising from the nasal limbus and extending across the cornea in a wing-shaped pattern. It is one of the most common ocular surface conditions in ophthalmology and optometry, particularly among patients with high cumulative UV light exposure, and bilateral presentation is the rule rather than the exception — bilateral pterygium is identified in a significant portion of patients presenting for initial evaluation, especially those in high-UV occupations such as farming, construction, fishing, and outdoor athletics.
H11.003 is the required code — per ICD-10-CM bilateral coding convention — when pterygium is confirmed in both eyes and neither eye’s subtype is further specified in the provider’s documentation. Do not code H11.001 (right eye) and H11.002 (left eye) simultaneously to represent bilateral involvement — when a bilateral code exists and bilateral disease is documented, the bilateral code must be assigned. As a profee coder, review the full encounter note, slit lamp documentation for each eye, corneal topography for each eye, and any surgical history before assigning H11.003 — the bilateral designation is appropriate only when both eyes are confirmed in the provider’s assessment, not assumed based on a single-eye exam.
Pterygium vs. Pseudopterygium — Critical Bilateral Coding Distinction
Feature True Bilateral Pterygium (H11.003) Pseudopterygium (H11.813) Origin Primary fibrovascular growth from bulbar conjunctiva crossing the limbus — bilateral Secondary adhesion of conjunctiva to cornea following trauma, chemical burn, or inflammatory scarring Limbal attachment Present bilaterally — true limbal attachment both eyes Absent — a probe passes beneath pseudopterygium at the limbus Progression Grows toward corneal center; may be stationary or progressive in each eye Does not grow in same manner; cicatricial adhesion UV association Strong bilateral UV-exposure association No UV association — associated with prior bilateral ocular surface injury Bilateral occurrence Very common — high UV exposure populations show bilateral rates approaching 50-70%2 Bilateral pseudopterygium is rare; requires bilateral ocular surface injury ICD-10-CM H11.00x-H11.06x H11.811-H11.819 Excludes1 H11.0x Excludes1 H11.81- Mutually exclusive at code level Excludes1 applies bilaterally — true pterygium and pseudopterygium cannot be coded simultaneously for the same eye. If one eye has true pterygium and the other has pseudopterygium, use H11.001 or H11.002 for the pterygium eye and H11.811 or H11.812 for the pseudopterygium eye — do not use H11.003 in that scenario.
Code Structure & Hierarchy
Code Tree
- Chapter: 7 — Diseases of the Eye and Adnexa (H00-H59)
- Block: H10-H11 — Disorders of Conjunctiva
- H11 — Other disorders of conjunctiva ← this category
- H11.0 — Pterygium of eye ← this subcategory
- H11.00 — Unspecified pterygium of eye
- H11.01 — Amyloid pterygium
- H11.02 — Central pterygium of eye
- H11.03 — Double pterygium of eye
- H11.04 — Peripheral pterygium of eye, stationary
- H11.05 — Peripheral pterygium of eye, progressive
- H11.06 — Recurrent pterygium of eye
- H11.81 — Pseudopterygium of conjunctiva ← Excludes1 to all H11.0x
Per ICD-10-CM Official Guidelines, when a condition is bilateral and a bilateral code exists, the bilateral code must be assigned — assigning H11.001 and H11.002 simultaneously is a coding convention violation and will trigger edit flags on claims. H11.003 is the single correct code whenever both eyes have unspecified pterygium confirmed in the provider’s assessment. The only exception is when the two eyes have different documented subtypes — for example, right eye progressive (H11.051) and left eye stationary (H11.042) — in which case two separate laterality-specific subtype codes are appropriate rather than a single bilateral unspecified code.
H11.003 vs. Sibling Bilateral Codes — Type Specificity Decision Table
Code Assign When Provider Documents… H11.003 ”Bilateral pterygium” — no further type specified for either eye (NOS) H11.013 Amyloid pterygium, bilateral — amyloid deposits confirmed histologically in both eyes H11.023 Central pterygium, bilateral — extends to or across the visual axis in both eyes H11.033 Double pterygium, bilateral — nasal AND temporal pterygium present in both eyes H11.043 Peripheral, stationary — bilateral; documented as not progressing in either eye H11.053 Peripheral, progressive — bilateral; documented as actively advancing in both eyes H11.063 Recurrent pterygium, bilateral — regrowth after prior excision in both eyes — do NOT use H11.0033 H11.001 + H11.052 Asymmetric subtypes — right eye unspecified NOS + left eye progressive; code each eye separately with the appropriate laterality-specific subtype code Before finalizing H11.003, review both eyes’ slit lamp findings and topography. If one eye is clearly advancing and the other is stable, the provider’s documentation supports two separate subtype-specific unilateral codes rather than the bilateral unspecified code.
Instructional Notes
Excludes1 — Mutually Exclusive
Cannot be coded together with H11.003 at the same encounter for the same bilateral condition:
- Pseudopterygium of conjunctiva, bilateral (H11.813) — a structurally and etiologically distinct entity representing secondary bilateral cicatricial adhesion; mutually exclusive with true bilateral pterygium coding at the H11.0 level
- If one eye has true pterygium and the other has pseudopterygium, do not use H11.003 — use the appropriate unilateral codes for each eye individually (H11.001 or H11.002 for the pterygium eye; H11.811 or H11.812 for the pseudopterygium eye)
Also Excludes1 at the H11 Category Level
- Keratoconjunctivitis (H16.2-) — classified separately and cannot be coded simultaneously as the same bilateral diagnosis expression
Coexisting Conditions — Separately Reportable
The following may be coded in addition to H11.003 when separately documented and confirmed bilaterally:
- Dry eye disease, bilateral (H04.123) — pterygium and dry eye very commonly coexist, particularly in bilateral high-UV-exposure cases; both are separately reportable when present and documented
- Corneal pannus or superficial corneal opacity, bilateral — evaluate whether H18.893 applies when significant bilateral corneal involvement is documented in advanced bilateral pterygium
- Exposure keratoconjunctivitis, bilateral (H16.213) — may coexist in advanced bilateral cases
Use Additional Code
Clinical Description
Bilateral pterygium is the predominant presentation pattern in high-UV-exposure populations and represents the natural history of a condition driven by cumulative UV-B radiation damage to limbal stem cells in both eyes over time. The nasal limbus is the most common origin bilaterally, due to the geometric optics of UV-B light entering the eye from the temporal visual field and focusing at the nasal limbus — a phenomenon known as the limbal focusing effect. Temporal pterygia can also occur bilaterally, and double pterygia (nasal AND temporal in the same eye) are seen in the most severely UV-exposed patients.
Pathophysiology (Bilateral Context):
- Bilateral UV-B exposure produces symmetric oxidative damage to limbal stem cells in both eyes simultaneously over years to decades
- The bilaterality of the condition reflects the systemic UV exposure pattern rather than any intraocular spread between eyes
- Asymmetry in pterygium size and progression between the two eyes is common — the right eye nasal pterygium may be more advanced than the left due to differences in sun exposure angle during driving or occupational activities (in countries where driving is on the right side of the road, the driver’s left nasal limbus receives more direct sun — a well-documented epidemiological finding)
- Limbal stem cell dysfunction in both eyes predisposes to bilateral recurrence after excision
Clinical Presentation (Bilateral):
- Bilateral pink-red fleshy fibrovascular lesions arising from the nasal limbus of both eyes
- Stocker’s line (iron line at the advancing head) may be visible at either or both lesion heads on slit lamp
- Symptoms often more pronounced in the more advanced eye; the less advanced eye may be nearly asymptomatic
- Bilateral induced corneal astigmatism — serial bilateral topography is essential; astigmatism magnitude and axis may differ significantly between eyes
- Bilateral visual field restriction is uncommon unless both pterygia are large and centrally located
- Patient may present for one eye and the contralateral pterygium is discovered on bilateral slit lamp exam — always document both eyes in the assessment
Clinical Subtypes (Bilateral Equivalents — All Map to H11.003 When Bilateral and Unspecified):
| Subtype | Right-Eye Code | Left-Eye Code | Bilateral Code |
|---|---|---|---|
| Unspecified NOS | H11.001 | H11.002 | H11.003 ← |
| Amyloid | H11.011 | H11.012 | H11.013 |
| Central | H11.021 | H11.022 | H11.023 |
| Double | H11.031 | H11.032 | H11.033 |
| Peripheral, stationary | H11.041 | H11.042 | H11.043 |
| Peripheral, progressive | H11.051 | H11.052 | H11.053 |
| Recurrent | H11.061 | H11.062 | H11.063 |
Asymmetric Bilateral Pterygium — When NOT to Use H11.003
When both eyes are affected but have different documented subtypes, the bilateral unspecified code does NOT apply. Assign two separate laterality-specific subtype codes. Examples:
Coding Guidelines
Official Guideline Reference
ICD-10-CM Official Guidelines FY2026, Section I.C.7 — Diseases of the Eye and Adnexa
- Assign H11.003 when the provider documents pterygium affecting both eyes without specifying the subtype for either eye. If subtypes are documented — even if only for one eye — use the most specific available codes, including the appropriate bilateral subtype code (H11.013-H11.063) if both eyes share the same documented subtype, or two separate laterality-specific codes if the eyes have different subtypes.
- Do not code H11.001 + H11.002 simultaneously — when bilateral involvement is documented and a bilateral code exists, the bilateral code (H11.003) is required by ICD-10-CM convention.
- H11.063 (recurrent bilateral pterygium) should be assigned — not H11.003 — when prior excision in both eyes is documented and bilateral regrowth has occurred. Review surgical history for both eyes before defaulting to the unspecified bilateral code.
- When pterygium is the primary reason for the encounter, H11.003 is the first-listed diagnosis. When identified as an incidental bilateral finding during a visit for another primary condition, it is coded as an additional diagnosis if examined and documented in the bilateral assessment.
Sequencing Tips
- Outpatient — First-listed diagnosis: H11.003 when bilateral pterygium is the primary reason for the encounter
- Treating only one eye today: H11.003 remains the appropriate ICD-10-CM code even when only one eye is being surgically treated at this encounter — the bilateral diagnosis reflects the patient’s total clinical picture. Append the appropriate laterality modifier (-RT or -LT) to the CPT code to indicate which eye is being treated.
- POA (inpatient): Virtually always Y — bilateral pterygium is a chronic, slowly progressive condition. POA = N is essentially never applicable.
- Asymmetric progression: If bilateral pterygium is documented but the two eyes are at different stages with documented subtypes, retire H11.003 and assign two separate subtype-specific laterality codes — document the transition in the note
- Post-excision one eye: If one eye has been surgically excised and the other remains untreated, retire H11.003 and assign the appropriate unilateral code for the untreated eye only — the operated eye is either healed (no active code needed) or recurrent (H11.061 or H11.062)
HCC Mapping
HCC Risk Adjustment
HCC Relevant: No HCC Model: CMS-HCC v28 — fully operative CY2026 HCC Category: Not mapped HCC Coefficient: 0.000 Risk Adjustment Impact: None
H11.003 carries no HCC weight under CMS-HCC v28. Bilateral pterygium is classified as a benign, non-systemic, anterior segment condition and does not meet the clinical severity threshold for HCC mapping under any version of the CMS-HCC model. Neither the unilateral nor bilateral pterygium codes carry HCC weight.
Associated HCC Opportunities
While H11.003 carries no HCC weight, verify and separately capture the following if documented in bilateral pterygium patients:
- Type 2 diabetes with bilateral ophthalmic complications — diabetic retinopathy codes (E11.35X3 for bilateral) carry HCC 122 weight under V28; capture separately
- Glaucoma — bilateral glaucoma commonly coexists in UV-exposed outdoor populations; certain glaucoma codes carry HCC weight under V28 depending on severity and type
- AMD, bilateral — capture with relevant HCC weight per V28 mapping if coexisting and documented
- Bilateral dry eye syndrome (H04.123) — no HCC weight but separately reportable and supports medical necessity for lubricant prescriptions and ocular surface management
MS-DRG Mapping
DRG Assignment
MS-DRG Description MDC GMLOS 124 Other Disorders of the Eye with MCC MDC 2 4.6 125 Other Disorders of the Eye with CC MDC 2 3.1 126 Other Disorders of the Eye without CC/MCC MDC 2 2.2
CC/MCC Status & Inpatient Context
- CC status: No
- MCC status: No
- HAC designation: No
- POA exempt: No
- Inpatient note: Inpatient admission for bilateral pterygium excision is essentially never performed — pterygium surgery (65420 or 65426) is exclusively outpatient ASC or office-based in practice. In the inpatient setting, H11.003 appears almost exclusively as a secondary diagnosis alongside a primary ocular or systemic condition. As the sole diagnosis, it groups to MS-DRG 126 in the absence of CC/MCC diagnoses. When a qualifying ICD-10-PCS surgical procedure is performed (right conjunctiva: 08B23ZZ; left conjunctiva: 08B33ZZ), the case groups to a surgical MS-DRG within MDC 02. Note that bilateral intraoperative eye surgery at the same session is uncommon — bilateral pterygia are typically staged across two separate operative encounters.
CPT Crosswalk
| CPT | Description | wRVU (approx.) | Global Period | Modifier Required |
|---|---|---|---|---|
| 92004 | Ophthalmological exam, new patient, comprehensive, with dilation | 2.67 | 0 days | N/A |
| 92014 | Ophthalmological exam, established patient, comprehensive, with dilation | 1.34 | 0 days | N/A |
| 92025 | Computerized corneal topography, unilateral or bilateral, with interpretation | 0.00 (TC/PC) | 0 days | 50 for bilateral |
| 92250 | Fundus photography with interpretation and report | 0.00 (TC/PC) | 0 days | N/A |
| 65430 | Scraping of cornea, diagnostic | 0.85 | 0 days | RT / LT per eye |
| 65420 | Excision or transposition of pterygium; without graft | ~3.00 | 90 days | RT or LT per eye |
| 65426 | Excision or transposition of pterygium; with graft | ~5.47 | 90 days | RT or LT per eye |
| 68100 | Biopsy of conjunctiva | ~1.00 | 0 days | RT / LT per eye |
Code Procedure When to Assign Recurrence Risk 65420 Excision — without graft Bare sclera technique; no conjunctival or amniotic membrane graft High recurrence (~30-80%) 65426 Excision — with graft Conjunctival autograft (CAU) or amniotic membrane transplant (AMT) placed following excision Lower recurrence (~5-15%) — current standard of care
- Operative note must document graft placement to support 65426 — document harvest site, graft dimensions, and fixation method (suture vs. fibrin glue) for each eye
- MMC alone does NOT constitute a graft — Mitomycin C does not upgrade 65420 to 65426
- Amniotic membrane graft: document product name and lot number (e.g., AmnioGraft, Prokera) for each eye treated
Bilateral Pterygium Surgery — CPT Modifier Guidance
When the same CPT code (e.g., 65426) is performed on both eyes at the same surgical session (uncommon but possible):
- Bill 65426--RT on one line AND 65426--LT on a separate line
- OR bill 65426--50 on one line (Medicare generally prefers modifier -50 on a single line for bilateral surgical procedures)
- Verify payer-specific bilateral billing rules — Medicare MPFS and commercial payers differ in their preferred bilateral modifier format
- When bilateral pterygium surgery is staged (right eye one day, left eye a separate date): bill each eye separately with -RT and -LT modifiers; no bilateral modifier applies
- The 90-day global period for each eye begins on its own date of service — staged bilateral surgeries create two separate global periods
NCCI Bundling
ICD-10-PCS Crosswalk
PCS Applicability
ICD-10-PCS applies in the inpatient setting only. Bilateral pterygium surgery in the inpatient setting is essentially nonexistent in current practice. If encountered, each eye requires its own PCS code — there is no single bilateral PCS code for conjunctival excision. The body part coded is the conjunctiva for each eye (right = body part 2; left = body part 3), not the cornea.
| PCS Code | Root Operation | Body Part | Approach | Device | Qualifier |
|---|---|---|---|---|---|
| 08B23ZZ | Excision | Conjunctiva, Right | Percutaneous | No Device | No Qualifier |
| 08B33ZZ | Excision | Conjunctiva, Left | Percutaneous | No Device | No Qualifier |
| 08T23ZZ | Resection | Conjunctiva, Right | Percutaneous | No Device | No Qualifier |
| 08T33ZZ | Resection | Conjunctiva, Left | Percutaneous | No Device | No Qualifier |
| 08R2X73 | Replacement | Conjunctiva, Right | External | Autologous Tissue Substitute | No Qualifier |
| 08R3X73 | Replacement | Conjunctiva, Left | External | Autologous Tissue Substitute | No Qualifier |
Character breakdown — excision of right conjunctiva (08B23ZZ):
- Section: 0 — Medical and Surgical
- Body System: 8 — Eye
- Root Operation: B — Excision
- Body Part: 2 — Conjunctiva, Right
- Approach: 3 — Percutaneous
- Device: Z — No Device
- Qualifier: Z — No Qualifier
(For left conjunctiva: body part changes to 3 — all other characters remain the same → 08B33ZZ)
PCS Root Operation Distinction
- Excision (08B23ZZ / 08B33ZZ) — portion of conjunctiva removed bilaterally (standard for bilateral pterygium excision)
- Resection (08T23ZZ / 08T33ZZ) — entire conjunctiva removed; not typical for pterygium alone
- Replacement (08R2X73 / 08R3X73) — applicable when conjunctival autograft is placed in each eye; device character 7 = Autologous Tissue Substitute; one PCS code per eye
ICD-10-CM Crosswalk
| Code | Description | Relationship |
|---|---|---|
| H11.001 | Unspecified pterygium, right eye | Unilateral right-eye equivalent |
| H11.002 | Unspecified pterygium, left eye | Unilateral left-eye equivalent |
| H11.009 | Unspecified pterygium, unspecified eye | Less specific — avoid if laterality (including bilateral) documented |
| H11.013 | Amyloid pterygium, bilateral | Use when amyloid deposits confirmed histologically, both eyes |
| H11.023 | Central pterygium, bilateral | Use when visual axis threatened or involved, both eyes |
| H11.033 | Double pterygium, bilateral | Use when nasal AND temporal pterygium present in both eyes |
| H11.043 | Peripheral pterygium, stationary, bilateral | Use when bilateral and documented as stable |
| H11.053 | Peripheral pterygium, progressive, bilateral | Use when bilateral and documented as actively advancing |
| H11.063 | Recurrent pterygium, bilateral | Use after prior excision with regrowth in both eyes — do not use H11.003 for bilateral recurrence |
| H11.813 | Pseudopterygium of conjunctiva, bilateral | Excludes1 — bilateral secondary cicatricial adhesion |
| H18.893 | Other specified disorders of cornea, bilateral | Associated bilateral corneal pannus or scarring |
| H04.123 | Dry eye syndrome, bilateral | May coexist — separately reportable |
| H16.213 | Exposure keratoconjunctivitis, bilateral | May coexist bilaterally in advanced cases |
| Z77.098 | Contact with/exposure to hazardous nonmedicinal chemicals | UV exposure history relevant to bilateral pterygium etiology |
Coding Examples
Example 1 — New Patient, Bilateral Pterygium Discovered on Dilated Exam
Scenario: A 54-year-old outdoor construction worker presents as a new patient for a comprehensive eye exam. Bilateral slit lamp exam reveals pink fleshy fibrovascular growths arising from the nasal limbus of both eyes. Neither pterygium approaches the visual axis. Provider documents “bilateral pterygium — type unspecified; both eyes.” Artificial tears recommended; surgery deferred.
First-listed Dx: H11.003 — Unspecified pterygium of eye, bilateral CPT: 92004 — Comprehensive ophthalmological exam, new patient, with dilation Notes: H11.003 is correct — bilateral confirmed, no subtype documented. No laterality modifier needed on the E/M code. Topography (92025--50) is appropriate at a future visit to baseline both eyes.
Example 2 — Established Patient, Bilateral Pterygium, Right Eye Surgical, Left Eye Monitored
Scenario: A 60-year-old patient with bilateral pterygium presents for pre-operative evaluation. Right eye pterygium is advancing toward the visual axis; left eye pterygium is stable and asymptomatic. Provider documents “bilateral pterygium — right eye progressive, surgical excision planned; left eye stationary, continue monitoring.”
ICD-10-CM: H11.051 — Peripheral pterygium, progressive, right eye (right eye subtype documented); H11.042 — Peripheral pterygium, stationary, left eye (left eye subtype documented) — do NOT use H11.003 — asymmetric subtypes require separate laterality-specific codes First-listed Dx (pre-op visit): H11.051 CPT: 92014 — Established patient exam; 92025--50 — Bilateral topography Notes: H11.003 is inappropriate here because provider has documented distinct subtypes for each eye. This is a key scenario where defaulting to the bilateral unspecified code would be a specificity error.
Example 3 — Bilateral Pterygium Excision, Right Eye with Autograft, Same Day
Scenario: A 47-year-old patient undergoes bilateral pterygium excision in the same surgical session (uncommon but documented). Right eye: excision with conjunctival autograft, fibrin glue fixation, 8 x 5 mm graft. Left eye: excision with conjunctival autograft, suture fixation, 7 x 4 mm graft. Provider documents “pterygium NOS, bilateral” in the pre-op assessment.
ICD-10-CM: H11.003 — Unspecified pterygium of eye, bilateral CPT Line 1: 65426--RT — Excision with graft, right eye CPT Line 2: 65426--LT — Excision with graft, left eye (OR: 65426--50 on a single line — verify payer preference for bilateral same-day surgical billing) Notes: Both eyes require separate CPT line items with laterality modifiers even though the ICD-10-CM diagnosis is a single bilateral code. Two global periods are created simultaneously — one for each eye. Document each eye’s graft harvest site, dimensions, and fixation method separately in the operative note to support 65426 for each eye independently.
Example 4 — Bilateral Recurrent Pterygium, Both Eyes
Scenario: A patient with a documented history of bilateral pterygium excision 2 years ago presents with regrowth documented in both eyes. Provider note states “bilateral recurrent pterygium — both eyes previously excised.”
First-listed Dx: H11.063 — Recurrent pterygium of eye, bilateral (do NOT use H11.003) CPT (if re-excision planned): 65426--RT and 65426--LT staged separately (or 65426--50 if same session) Notes: H11.003 is incorrect once bilateral recurrence is documented — H11.063 is required. Conjunctival autograft or amniotic membrane is strongly preferred for recurrent cases bilaterally.
Example 5 — Inpatient Secondary Diagnosis, Bilateral Pterygium, Combined Surgical Admission
Scenario: A 68-year-old patient admitted for bilateral cataract extraction (staged, right eye this admission). Bilateral pterygium is noted on slit lamp exam at the ophthalmology pre-op assessment — no treatment for pterygium during this admission. Provider documents “bilateral pterygium” in the assessment.
Principal Dx: H26.013 — Combined forms of subcapsular cataract, bilateral (reason for admission) Additional Dx: H11.003 — Unspecified pterygium of eye, bilateral (documented, examined, no treatment this admission) POA: Y — bilateral pterygium is a chronic condition present prior to admission
Example 6 — One Eye Treated, Bilateral Diagnosis Still Active
Scenario: A 52-year-old patient with known bilateral pterygium has right eye pterygium excision today. Left eye pterygium is being deferred. Provider documents “bilateral pterygium — right eye excision today; left eye to be scheduled.”
ICD-10-CM (today’s surgical encounter): H11.003 — Unspecified pterygium of eye, bilateral (bilateral disease remains the clinical picture even though only one eye is treated today) CPT: 65426--RT Notes: H11.003 correctly reflects the total diagnosis. The -RT modifier on the CPT indicates which eye is being treated today. At the left eye’s surgical encounter, H11.002 or H11.003 as appropriate will be the diagnosis code — if the right eye has healed without issue, H11.002 (left eye only) becomes the active code at that future visit.
Coding Pitfalls & Tips
Common Errors
- Coding H11.001 + H11.002 simultaneously instead of H11.003 — when bilateral involvement is documented and a bilateral code exists, the bilateral code is required per ICD-10-CM convention; dual unilateral codes are a convention violation
- Using H11.003 for bilateral recurrent pterygium — once bilateral prior excision and bilateral regrowth are documented, H11.063 is required
- Confusing H11.003 and H11.813 (bilateral pseudopterygium) — Excludes1 applies; do not code both for the same bilateral encounter; if one eye has true pterygium and the other has pseudopterygium, use separate unilateral codes
- Billing 65420 when bilateral grafts were placed — if operative notes for both eyes document conjunctival autograft or amniotic membrane placement, 65426 must be billed for each eye
- Forgetting per-eye laterality modifiers on CPT — -RT and -LT are required on all surgical CPT lines even when the ICD-10-CM diagnosis code is bilateral; the bilateral ICD-10 code does not eliminate the need for laterality modifiers on the CPT side
- Using H11.003 when asymmetric subtypes are documented — if the provider documents different subtypes for each eye, two separate laterality-specific subtype codes are required rather than the bilateral unspecified code
- Carrying H11.003 forward after excision of one eye without updating to the unilateral code at subsequent encounters when only one eye remains untreated
Pro Tips
- Always examine and document both eyes — bilateral pterygium is common in high-UV-exposure patients; if only one eye is examined and documented, only the unilateral code is supported. Review every bilateral slit lamp documentation to confirm whether H11.003 or a unilateral code is appropriate.
- Bilateral topography (92025-50) at baseline and serial follow-up provides objective documentation of bilateral disease, progression in each eye independently, and induced astigmatism bilaterally — this data supports both the bilateral ICD-10 code and medical necessity for surgical planning
- Staged bilateral surgery creates two separate 90-day global periods — track each eye’s global period independently to avoid bundling follow-up claims for the wrong eye’s post-op period
- Driver’s asymmetry pattern — in right-side-of-the-road driving countries, the left nasal pterygium is often more advanced in drivers due to greater UV exposure from the driver’s side window; document which eye is more advanced and whether asymmetric subtypes apply
- When a bilateral unspecified code (H11.003) is being used for a patient with clearly advancing disease in one eye, consider flagging for CDI query to upgrade to asymmetric subtype-specific codes — the distinction between progressive and stationary has real surgical planning and medical necessity implications even though both currently map to the H11.00x unspecified family
CDI Query Opportunities
CDI Flags
- Subtype documentation for each eye: What is the clinical type in each eye — stationary peripheral, progressive peripheral, central, double, or amyloid? Query the provider to document subtypes for each eye individually, which may retire H11.003 in favor of more specific bilateral or per-eye codes
- Recurrence history — bilateral: Has the patient had prior excision of either or both eyes? If both eyes have been previously excised and both show regrowth, H11.063 is required — query if bilateral surgical history is present but “recurrent” is not explicitly stated
- True pterygium vs. pseudopterygium: Has a probe test been performed for each eye? Query if documentation is ambiguous about true limbal attachment in either or both eyes
- Asymmetric progression: Does the provider note or topography data indicate that one eye is progressing while the other is stationary? If so, document each eye’s subtype separately — this supports two separate per-eye subtype codes over H11.003
- Graft type for surgical cases: Conjunctival autograft? Amniotic membrane? Document separately for each eye in the operative note — each eye must independently support 65426 if that code is billed for both
- Associated bilateral dry eye: Is bilateral dry eye disease (H04.123) documented and being treated? Both conditions are separately reportable and should each be captured
Related Codes
- Laterality family: H11.001, H11.002, H11.009
- Specific pterygium subtypes, bilateral: H11.013, H11.023, H11.033, H11.043, H11.053, H11.063
- Pseudopterygium (Excludes1): H11.811, H11.812, H11.813
- Associated bilateral corneal findings: H18.893
- Associated bilateral anterior segment conditions: H04.123, H16.213
- CPT crosswalk: 65420, 65426, 92014, 92004, 92025, 92250, 68100
- PCS crosswalk: 08B23ZZ, 08B33ZZ, 08T23ZZ, 08T33ZZ, 08R2X73, 08R3X73
- AAPC Codify — ICD-10-CM H11.003 & H11.0, aapc.com
- Unbound Medicine — H11.003 Pterygium of Eye, Bilateral, unboundmedicine.com
- CMS — ICD-10-CM Official Guidelines for Coding and Reporting FY2026, cms.gov
- CMS — ICD-10-CM/PCS MS-DRG v37.2 Definitions Manual, cms.gov
- FindACode — ICD-10-CM H11.003, findacode.com
- MedPAC — MA Part D CY2027 Comment Letter, medpac.gov (2026)
- BCA — HCC Updates: Capturing Risk Accurately in 2026, bcarev.com (2026)
- Wolters Kluwer — How CMS-HCC Version 28 Will Impact RAF Scores, wolterskluwer.com
- AAPC — CPT Code 65426 Excision Procedures on the Cornea, aapc.com
- AAPC — CPT Code 65420 Excision Procedures on the Cornea, aapc.com
- CMS — 2026 NCCI Medicare Coding Policy Manual, cms.gov
- Review of Ophthalmology — Coding and Reimbursement: 2026 Update, reviewofophthalmology.com (2026)
- GenHealth.ai — ICD-10-CM H11.0 Pterygium of Eye, genhealth.ai
- MD Clarity — CPT Code 65426: What It Is, Modifiers, Reimbursement, mdclarity.com
- AAPC — ICD-10-CM H11.81 Pseudopterygium of Conjunctiva, aapc.com
- CMS — ICD-10-CM/PCS MS-DRG v33.0 Definitions Manual, cms.gov