Crystal's MCW Coder Hub🧬 ICD-10 CM H35.373 — Puckering of Macula, Bilateral
Quick Reference
Description
ICD-10 CM H35.373 represents puckering of the macula affecting both eyes simultaneously, documented at the same encounter. An epiretinal membrane (ERM) is present on the inner retinal surface of both maculas — each eye independently harboring a fibrocellular proliferative membrane that exerts tangential traction causing wrinkling, distortion, and puckering of the macular architecture bilaterally.
Also known as: bilateral epiretinal membrane (ERM), bilateral macular pucker, bilateral cellophane maculopathy, bilateral preretinal fibrosis, bilateral surface wrinkling retinopathy. All of these terms map to H35.373 when both eyes are involved at the same encounter.
Critical Billing Rule — When to Use H35.373
ICD-10 CM H35.373 is appropriate only when ERM is actively present and documented in both eyes at the current encounter. It is a single code replacing the combination of H35.371 + H35.372 — do not bill both unilateral codes together.
Bilateral ERM does not necessarily mean both eyes are symptomatic or surgical — one eye may have advanced macular pucker requiring surgery while the fellow eye has only mild cellophane maculopathy under observation. Both must be documented in the provider’s assessment at the visit for H35.373 to apply.
Code Structure & Hierarchy
Code Tree
- Chapter: 7 — Diseases of the Eye and Adnexa (H00-H59)
- Block: H30-H36 — Disorders of Choroid and Retina
- H35 — Other retinal disorders
- H35.3 — Degeneration of macula and posterior pole ← this branch
- H35.30 — Unspecified macular degeneration
- H35.31 — Nonexudative (dry) AMD
- H35.32 — Exudative (wet) AMD
- H35.33 — Angioid streaks of macula
- H35.34 — Macular cyst, hole, or pseudohole
- H35.35 — Cystoid macular degeneration
- H35.36 — Drusen of macula
- H35.37 — Puckering of macula ← this subcategory
- H35.38 — Toxic maculopathy
Laterality Transition Logic — Dynamic Over Time
ERM is a progressive condition — laterality coding may change across encounters as disease evolves or is treated:
Clinical Situation Correct Code ERM both eyes, same encounter, neither treated H35.373 ERM both eyes, one eye treated this visit H35.373 (bilateral still documented) + surgical CPT with laterality modifier on treated eye Prior bilateral ERM; one eye surgically treated at prior visit; other eye still active H35.371 or H35.372 for the remaining active untreated eye — downgrade from bilateral Previously unilateral ERM; fellow eye now develops ERM Upgrade from H35.371 or H35.372 to H35.373 ERM right eye only H35.371 ERM left eye only H35.372 Reassess laterality coding at every encounter — do not carry H35.373 forward automatically if surgical treatment has resolved one eye.
Instructional Notes
Excludes2 — Not Included Here, May Co-exist
The following may be coded in addition to H35.373 when both conditions are present and documented bilaterally:
- Macular cyst, hole, or pseudohole, bilateral (H35.343) — coexisting bilateral macular hole or pseudohole; query provider for OCT confirmation distinguishing pseudohole from true ERM traction pattern
- Cystoid macular edema, bilateral (H35.813) — may develop secondary to bilateral ERM traction; separately reportable when explicitly documented bilaterally
- Bilateral diabetic macular edema — code via the diabetic retinopathy combination codes (E11.3213, E11.3313, etc.) rather than H35.813 when diabetic etiology
Use Additional Code
When ERM is secondary in either or both eyes, code the underlying condition per eye:
- Right eye post-surgical → H59.811 — Chorioretinal scars after surgery for detachment, right eye
- Left eye post-surgical → H59.812 — Chorioretinal scars after surgery for detachment, left eye
- Bilateral post-inflammatory → applicable bilateral H30.- code
- PVD bilateral → H43.893 — Vitreous degeneration, bilateral (when PVD is separately documented as a distinct active finding in both eyes)
- If etiology differs per eye (e.g., right eye idiopathic, left eye post-detachment repair), code the left eye secondary etiology only (H59.812) alongside H35.373
Clinical Description
Bilateral macular puckering occurs through the same pathophysiologic mechanism as unilateral ERM — fibrocellular proliferation on the inner limiting membrane (ILM) — but affecting both eyes, typically at different stages of severity and progression. Bilateral symmetry is not the rule; it is common for one eye to have advanced macular pucker requiring surgery while the fellow eye has only early cellophane maculopathy under watchful observation.
Why bilateral ERM occurs: The most common initiating event — posterior vitreous detachment (PVD) — may occur sequentially in both eyes over months to years, with each PVD potentially seeding the conditions for ERM formation. Idiopathic bilateral ERM is not uncommon in patients over 60 and is often discovered incidentally when the fellow eye is examined after the symptomatic eye presents. Secondary causes (retinal detachment repair, uveitis, vascular disease) may affect both eyes if the underlying condition is bilateral.
Asymmetric bilateral presentation — the clinical norm:
- Dominant symptomatic eye — significant metamorphopsia, reduced BCVA, thick ERM on OCT, surgical candidate
- Fellow eye — often milder; may show only a thin reflective band on OCT (cellophane stage), minimal or no metamorphopsia, managed with observation
- Documentation imperative: Both eyes must be documented in the provider’s assessment at the visit for H35.373 to apply — fundus exam, OCT, and provider note must reflect bilateral findings
Bilateral ERM — special clinical considerations:
- Surgical sequencing: When bilateral vitrectomy is planned, procedures are typically staged (separate sessions) rather than performed simultaneously — each session is coded with the appropriate unilateral CPT modifier (-RT or -LT)
- Dominant eye prioritization: The eye with worse acuity and greater metamorphopsia is typically treated first; the fellow eye is re-evaluated post-operatively before a second surgical decision is made
- Anisometropia risk: Asymmetric bilateral ERM can cause significant anisometropia and interocular visual acuity disparity — relevant for surgical candidacy discussion and documentation
Coding Guidelines
Official Guideline Reference
ICD-10-CM Official Guidelines FY2025, Section I.C.7 — Diseases of the Eye and Adnexa
- Laterality must be coded to the highest level of specificity supported by documentation. When bilateral disease is documented at the encounter, H35.373 is the appropriate single code — do not assign H35.371 and H35.372 simultaneously.
- The bilateral code applies when ERM is documented in both eyes at the current encounter, regardless of whether both eyes are symptomatic or whether only one eye is being treated surgically at that visit.
- When secondary etiology differs between eyes, code each secondary condition separately in addition to H35.373.
Sequencing Tips
- Outpatient — First-listed diagnosis: H35.373 when bilateral macular pucker is the primary reason for the encounter (bilateral surveillance visit, pre-op evaluation for staged bilateral surgery, new diagnosis visit)
- Surgical encounter — one eye treated: H35.373 remains the diagnosis code (bilateral disease is still present); the CPT code carries the laterality specificity via -RT or -LT modifier
- Surgical encounter — both eyes treated same session: Rare for vitrectomy; if performed, H35.373 as first-listed; two separate CPT lines with -RT and -LT modifiers respectively; verify payer bilateral surgery reimbursement rules (50% reduction second eye under Medicare bilateral surgery indicator)
- After one eye surgically treated at prior visit: Reassess — if the operated eye no longer has active ERM, downgrade to the unilateral code for the remaining active eye (H35.371 or H35.372)
- POA (inpatient): Almost always Y — bilateral macular pucker is a chronic progressive condition present before admission
HCC Mapping
HCC Risk Adjustment
HCC Relevant: No HCC Model: CMS-HCC v28 HCC Category: Not mapped HCC Coefficient: 0.000 Risk Adjustment Impact: None
H35.373 carries no HCC weight — identical to H35.371 and H35.372 in this regard. The bilateral designation does not add RAF value. However, coexisting conditions that commonly accompany bilateral ERM carry significant HCC weight and must be captured separately.
Associated HCC Opportunities — Bilateral Context
Bilateral ERM frequently occurs in older Medicare patients who also have:
- Bilateral exudative AMD (H35.3231 with active CNV) — HCC 124; confirm and code per eye staging
- Bilateral nonproliferative diabetic retinopathy (E11.3413) — HCC 122
- Type 2 diabetes (E11.-) — HCC 37
- Bilateral drusen (H35.363) — no HCC, but documents AMD risk and supports future AMD coding Each must appear in the provider’s assessment at the current encounter to be coded — do not pull from imaging reports alone
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 or without CC/MCC MDC 2 3.1
CC/MCC Status
- CC status: No
- MCC status: No
- HAC designation: No
- POA exempt: No
- Inpatient note: Inpatient admission for bilateral macular puckering alone is rare. H35.373 in the inpatient setting is almost always a secondary diagnosis. When bilateral vitrectomy with membrane peel is performed inpatient, both PCS codes are required (one per eye). DRG is driven by the principal diagnosis and CC/MCC secondary codes.
CPT Crosswalk
| CPT | Description |
|---|---|
| 67041 | Vitrectomy, pars plana; with removal of preretinal cellular membrane (e.g., macular pucker) |
| 67042 | Vitrectomy, pars plana; with removal of internal limiting membrane (ILM) |
| 67043 | Vitrectomy, pars plana; with removal of subretinal membrane |
| 92134 | OCT posterior segment, with interpretation and report, unilateral or bilateral |
| 92250 | Fundus photography with interpretation and report |
| 92225 | Ophthalmoscopy, extended, with retinal drawing, initial |
| 92226 | Ophthalmoscopy, extended, with retinal drawing, subsequent |
Bilateral Surgery Billing — Critical Rules
When bilateral vitrectomy with membrane peel is performed (same session or staged):
Same session (uncommon):
- Bill two separate CPT lines: 67041-RT and 67041-LT (or 67042-RT and 67042-LT)
- Do NOT use modifier -50 for bilateral vitrectomy without confirming payer policy — Medicare requires separate line items with -RT and -LT
- Medicare bilateral surgery indicator applies — expect 50% reduction on the second eye
- Verify ASC and facility bilateral reimbursement rules before scheduling same-session bilateral vitrectomy
Staged (separate sessions — standard of care):
- First session: 67041-RT or -LT (appropriate eye); diagnosis code H35.373 (bilateral still present)
- Second session (after fellow eye re-evaluation): 67041-LT or -RT; by this time, if operated eye is resolved, use unilateral diagnosis code for the remaining active eye
67041 vs. 67042 per eye:
ICD-10-PCS Crosswalk
PCS Applicability
ICD-10-PCS applies in the inpatient setting only. If bilateral vitrectomy is performed inpatient, a separate PCS code is required for each eye.
| PCS Code | Root Operation | Body Part | Approach | Device | Qualifier |
|---|---|---|---|---|---|
| 08N33ZZ | Release | Vitreous, Right | Percutaneous | No Device | No Qualifier |
| 08N34ZZ | Release | Vitreous, Left | Percutaneous | No Device | No Qualifier |
| 08B33ZZ | Excision | Vitreous, Right | Percutaneous | No Device | No Qualifier |
| 08B34ZZ | Excision | Vitreous, Left | Percutaneous | No Device | No Qualifier |
Bilateral Inpatient Coding
When both eyes are operated in the same inpatient session, assign both right and left PCS codes — one per eye. ICD-10-PCS does not have a bilateral body part value for vitreous; each eye requires its own code. Reference 08N33ZZ and 08N34ZZ for Release, or 08B33ZZ and 08B34ZZ for Excision, depending on root operation selected per facility policy.
ICD-10-CM Crosswalk
| Code | Description | Relationship |
|---|---|---|
| H35.371 | Puckering of macula, right eye | Unilateral — use when left eye resolves after treatment |
| H35.372 | Puckering of macula, left eye | Unilateral — use when right eye resolves after treatment |
| H35.379 | Puckering of macula, unspecified eye | Less specific — avoid if laterality known |
| H35.343 | Macular cyst, hole, or pseudohole, bilateral | Related bilateral macular pathology — Excludes2; may coexist |
| H35.353 | Cystoid macular degeneration, bilateral | May co-occur bilaterally |
| H35.363 | Drusen of macula, bilateral | May co-occur — AMD risk marker |
| H35.3231 | Exudative AMD, bilateral, with active CNV | Co-occurring bilateral condition — HCC 124 |
| H33.003 | Unspecified retinal detachment, bilateral | Prior retinal detachment — bilateral secondary ERM etiology |
| H43.893 | Vitreous degeneration, bilateral | Bilateral PVD — common antecedent to bilateral idiopathic ERM |
| H59.811 | Chorioretinal scars after surgery, right eye | Right eye secondary etiology when applicable |
| H59.812 | Chorioretinal scars after surgery, left eye | Left eye secondary etiology when applicable |
| E11.3213 | Type 2 DM with mild NPDR, bilateral, without macular edema | Diabetic comorbidity — code separately |
| Z96.1 | Presence of intraocular lens | Prior cataract surgery — bilateral IOL history relevant |
Coding Examples
Example 1 — Bilateral ERM Surveillance Visit, Asymmetric Severity, Outpatient
Scenario: A 74-year-old Medicare patient presents for bilateral macular pucker follow-up. OCT right eye shows dense ERM with macular thickening and loss of foveal contour; BCVA right eye 20/80. OCT left eye shows thin cellophane ERM with mild surface irregularity and preserved foveal contour; BCVA left eye 20/30, mildly symptomatic. Provider documents bilateral macular pucker in the assessment. Right eye surgical; left eye under observation. Extended ophthalmoscopy and bilateral OCT performed. Drusen bilateral also documented. First-listed Dx: H35.373 — Puckering of macula, bilateral Additional Dx: H35.363 — Drusen of macula, bilateral CPT: 92226 — Extended ophthalmoscopy, subsequent (bilateral); 92134 — OCT posterior segment with interpretation Notes: Both eyes are documented in the assessment — H35.373 applies even though only one eye is symptomatic and surgical. Do not split into H35.371 + H35.372. Drusen coded separately as an additional documented finding. Right eye surgical planning should begin.
Example 2 — Right Eye Vitrectomy with ERM Peel; Fellow Left Eye Bilateral ERM Still Documented, ASC
Scenario: Same patient from Example 1 returns for right eye pars plana vitrectomy with ERM peel. At pre-op evaluation, left eye ERM still present on OCT. Surgeon documents bilateral macular pucker in the pre-op assessment. Right eye is treated surgically; left eye observation continues. First-listed Dx: H35.373 — Puckering of macula, bilateral (both eyes still have active ERM at this encounter) Additional Dx: H35.363 — Drusen of macula, bilateral CPT: 67041-RT — Vitrectomy with ERM peel, right eye Notes: H35.373 remains the diagnosis because bilateral ERM is still present at this encounter — the left eye has not yet been treated. The CPT carries the right eye laterality via -RT. At the next post-op visit, reassess — if the right eye ERM has resolved, downgrade to H35.372 (left eye only) for ongoing follow-up encounters.
Example 3 — Post-op Right Eye; Left Eye Now Active Surgical Candidate — Laterality Downgrade
Scenario: Six weeks post right eye vitrectomy. Right eye OCT shows resolved ERM; BCVA right eye improved to 20/30. Left eye macular pucker has progressed; BCVA left eye 20/100; provider recommends left eye vitrectomy with combined ERM and ILM peel. First-listed Dx: H35.372 — Puckering of macula, left eye (right eye ERM resolved; bilateral code no longer appropriate) Additional Dx: Z96.1 — Presence of intraocular lens (if pseudophakic) CPT: 92226-LT — Extended ophthalmoscopy, subsequent; 92134 — OCT bilateral Notes: H35.373 is retired at this encounter — right eye ERM is resolved, so bilateral is no longer accurate. H35.372 replaces it going forward. This is the correct laterality downgrade workflow. Document clearly in the note that right eye ERM is resolved to support the code change.
Example 4 — Newly Discovered Bilateral ERM, Initial Diagnosis Visit
Scenario: A 68-year-old presents with metamorphopsia right eye. Dilated fundus exam and OCT unexpectedly reveal ERM in both eyes — right eye moderate pucker, left eye early cellophane maculopathy. Provider documents bilateral epiretinal membrane in the assessment for the first time. First-listed Dx: H35.373 — Puckering of macula, bilateral (new diagnosis, both eyes documented) CPT: 92225-RT, 92225-LT — Extended ophthalmoscopy with retinal drawing, initial (separate lines per eye); 92134 — OCT bilateral Notes: Use 92225 (initial) rather than 92226 (subsequent) since this is the first diagnosis and documentation of bilateral ERM. Two 92225 lines with -RT and -LT may be appropriate — verify payer bilateral ophthalmoscopy policy. Some payers bundle bilateral to one unit; others accept two lines.
Coding Pitfalls & Tips
Common Errors
- Billing H35.371 + H35.372 on the same claim when both eyes have ERM at the same encounter — use H35.373 instead; dual unilateral codes are incorrect and may trigger payer edits
- Carrying H35.373 forward on subsequent visits after one eye has been surgically treated and ERM resolved — reassess laterality at every encounter and downgrade to H35.371 or H35.372 when one eye is no longer affected
- Assigning H35.373 when only one eye has documented ERM at the current encounter and the other eye had ERM in the past — bilateral requires current active bilateral disease, not historical bilateral disease
- Using modifier -50 for bilateral vitrectomy without confirming payer policy — Medicare requires separate line items (-RT and -LT) not -50 for eye codes; -50 may apply for some non-ophthalmic codes but is not standard for eye surgery
- Billing 67041 and 67042 together for the same eye — 67042 subsumes 67041; never dual bill for the same eye regardless of whether ERM and ILM are both peeled
- Failing to document both eyes in the provider’s assessment when bilateral ERM is present — if only one eye appears in the assessment/plan, only that eye can be coded; H35.373 requires bilateral documentation in the provider note
Pro Tips
- Establish a clear laterality log in your vault or tracking system for patients who transition from H35.373 → unilateral codes post-surgery — the code change is clinically meaningful and auditors may question it without supporting documentation of ERM resolution
- When the surgical eye is treated and the fellow eye is under observation, always document both eyes in the provider’s assessment even at the surgical visit — this protects the H35.373 coding at the surgical encounter and keeps the bilateral picture clear
- OCT reports must be signed and interpreted by the provider — bilateral OCT findings in the imaging report alone do not support bilateral coding; the provider’s note must reflect bilateral ERM in the assessment and plan
- For staged bilateral surgery, confirm that the diagnosis code is updated appropriately at each surgical session — H35.373 for the first surgery (both eyes still present), then unilateral for the second surgery if the first eye has resolved
- Bilateral ERM in a young patient (under 50) without PVD history warrants query for secondary etiology — inflammatory, vascular, or traumatic cause may be present and separately codable in both eyes
CDI Query Opportunities
CDI Flags
- Bilateral confirmation at current encounter: Is ERM documented in both eyes in the provider’s assessment at this specific visit? If only one eye appears in the assessment (even if both were examined), only that eye can be coded — query the provider to include bilateral findings in the assessment if both eyes have OCT-confirmed ERM
- Laterality transition — post-treatment: Has one eye been surgically treated at a prior encounter? Query/verify whether ERM has resolved in the treated eye — if yes, H35.373 should be downgraded to the unilateral code for the remaining active eye at this encounter
- Secondary etiology — per eye: Is the bilateral ERM idiopathic, or is there a secondary cause in either or both eyes? History of bilateral retinal detachment repair, bilateral laser, bilateral uveitis? Query for explicit linkage per eye → H59.811, H59.812, or applicable H30.- codes
- Coexisting bilateral macular pathology: OCT evidence of bilateral CME (H35.813), bilateral pseudohole (H35.343), or bilateral subretinal fluid? Query provider to separately document and distinguish from ERM-related traction distortion
- Bilateral AMD or diabetic retinopathy: Are bilateral drusen (H35.363), bilateral AMD (H35.3231), or bilateral diabetic retinopathy (E11.3413) present? These carry HCC weight — confirm they appear in the bilateral provider assessment, not just the OCT or imaging report
- PVD bilateral documentation: Is bilateral PVD (H43.893) documented as a distinct active finding? Separately codable when noted in the provider’s assessment as an active condition
- Surgical sequencing discussion: Has the provider documented which eye is to be treated first and the rationale? This supports medical necessity for staged bilateral surgery and the laterality logic in claim submission
Related Codes
- Unilateral equivalents: H35.371 (right only), H35.372 (left only), H35.379 (unspecified)
- Related bilateral macular conditions: H35.343, H35.353, H35.363, H35.813
- Bilateral AMD crosswalk: H35.3131, H35.3231
- Secondary etiology codes: H59.811, H59.812, H33.003, H43.893
- Bilateral diabetic eye disease: E11.3213, E11.3413, E11.3513
- CPT crosswalk: 67041, 67042, 92134, 92250, 92225, 92226
- PCS crosswalk: 08N33ZZ, 08N34ZZ, 08B33ZZ, 08B34ZZ
Sources
ICD-10-CM Official Guidelines for Coding and Reporting FY2025. CMS/NCHS. ICD-10-CM Tabular List of Diseases and Injuries FY2025. CMS. CMS MS-DRG Definitions Manual v42. Centers for Medicare & Medicaid Services. CMS-HCC Risk Adjustment Model v28 Coefficients and Category Mappings. CMS, 2024. AHA Coding Clinic for ICD-10-CM/PCS. American Hospital Association. AAO Coding Coach — Ophthalmology CPT and ICD-10 Reference 2025. American Academy of Ophthalmology. CMS NCCI Policy Manual FY2025, Chapter 9 — Eye and Ocular Adnexa. Bhatt NS, et al. Epiretinal membrane — diagnosis, management, and outcomes. American Academy of Ophthalmology EyeWiki.