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T85.21XA

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T85.21XA — Breakdown (Mechanical) of Intraocular Lens, Initial Encounter

Code Overview

T85.21XA is a billable ICD-10-CM diagnosis code for breakdown (mechanical) of intraocular lens, initial encounter. It belongs to the T85.2 subcategory (Mechanical complication of intraocular lens) within T85 (Complications of other internal prosthetic devices, implants and grafts), Chapter 19 (Injury, Poisoning and Certain Other Consequences of External Causes, S00-T88).

The 7th character “A” designates initial encounter — the patient is actively receiving evaluation and/or treatment for this complication. The double “X” placeholder in positions 4 and 5 is structurally required to reach the 7th character position. T85.21XA sits within the broader family of IOL mechanical complication codes (T85.2-) and captures the specific mechanism of structural failure — the IOL itself has broken, cracked, fractured, or otherwise failed mechanically — as distinct from displacement/dislocation (T85.22XA) or other mechanical complications (T85.29XA).

T85.21XA is the principal diagnosis for encounters where IOL breakdown is the reason for care. It is governed by the Chapter 19 coding guideline requiring that the seventh character “A” be used for every encounter while active treatment is ongoing, regardless of the number of providers or encounters involved during the treatment episode.

Full Code Description

ElementDetail
Full CodeT85.21XA
DescriptionBreakdown (mechanical) of intraocular lens, initial encounter
Encounter TypeA = initial encounter (active treatment phase)
PlaceholderXX in positions 4 and 5 — required to reach 7th character
BillableYes
Chapter19 — Injury, Poisoning and Certain Other Consequences of External Causes
BlockT80-T88 — Complications of surgical and medical care, NEC
CategoryT85 — Complications of other internal prosthetic devices, implants and grafts
SubcategoryT85.2 — Mechanical complication of intraocular lens
LateralityNot applicable — T85.21 does not differentiate OD vs OS
7th CharacterA = initial; D = subsequent; S = sequela
Valid FYFY2025 (Oct 1, 2024 - Sep 30, 2025)

Clinical Description

What Is IOL Breakdown (Mechanical)?

Mechanical breakdown of an intraocular lens refers to physical structural failure of the IOL device itself — meaning the material, design, or components of the artificial lens have fractured, cracked, broken, or degraded in a manner that compromises its structural integrity and/or optical function. This is distinct from:

  • Displacement/dislocation — the IOL is structurally intact but has shifted position (T85.22XA)

  • Other mechanical complications — decentration, subluxation, or other mechanical problems without frank structural failure (T85.29XA)

  • Infection/inflammatory reaction — non-mechanical complications (T85.79XA)

  • Posterior capsular opacification (PCO) — a separate entity involving the lens capsule itself, not the IOL (H26.4-)

IOL Anatomy — Foundation for Understanding Breakdown

A modern intraocular lens is a precision medical device consisting of:

Optic:
The central circular refractive element that focuses light onto the retina. Typically 5.5-6.5 mm in diameter. Manufactured from:

  • PMMA (polymethylmethacrylate) — rigid; historical; still used in resource-limited settings; most prone to fracture from physical force

  • Hydrophilic acrylic — soft, foldable, high water content (18-26%); associated with IOL calcification (glistenings, subsurface nanoglistening); opacification is a major late complication

  • Hydrophobic acrylic — soft, foldable, low water content; current gold standard; lower opacification rates but may develop glistenings

  • Silicone — foldable; older premium material; oil droplets from silicone oil tamponade adhere to silicone IOLs, causing visual disturbance; contraindicated in patients who may require silicone oil

Haptics:
The flexible arm-like extensions that extend from the optic and anchor the IOL within the capsular bag, ciliary sulcus, or (in secondary/sutured cases) the sclera or iris. Haptic designs include:

  • C-loop haptics — most common; flexible loops in PMMA or PVDF material

  • Plate haptics — solid plate design (some premium multifocal and EDOF lenses)

  • Modified C, J, L-loop variants — manufacturer-specific designs

Haptics are the most mechanically vulnerable component of the IOL and are the most frequent site of breakdown/fracture.

Mechanisms and Types of IOL Breakdown

1. Haptic Fracture
The most common form of IOL mechanical breakdown. The haptic — typically the junction between the haptic and the optic (the “haptic-optic junction”) — fractures under mechanical stress. Causes include:

  • Intraoperative stress — haptic fracture during insertion through a small wound, especially with injector cartridges; the haptic may crack inside the cartridge under injection pressure (particularly with trifocal and EDOF lenses with modified haptic geometries)

  • Forceps manipulation — during IOL repositioning or explantation

  • Spontaneous late fracture — material fatigue over years of in vivo stress, particularly in PMMA haptics; may occur years to decades after implantation

  • Nd:YAG laser energy — very rare; misdirected or inadvertent YAG capsulotomy laser energy can nick or fracture a haptic if the IOL is in the beam path

A fractured haptic causes asymmetric haptic support — the IOL optic tilts or decenters toward the side of the broken haptic, producing:

  • Irregular astigmatism from IOL tilt

  • Monocular diplopia or ghosting

  • Reduced best-corrected visual acuity

  • Glare and dysphotopsia from IOL edge effects

2. Optic Fracture
Structural fracture of the central refractive optic itself. Rarer than haptic fracture. Causes include:

  • Intraoperative trauma — during IOL insertion, explantation, or manipulation; particularly during exchange or repositioning procedures

  • Postoperative blunt ocular trauma — direct impact to the eye causing internal mechanical disruption; though the capsular bag provides some protection, severe trauma can fracture even foldable IOLs

  • PMMA IOL-specific fracture — rigid PMMA lenses are more susceptible to optic fracture from physical impact than foldable materials

Note

Optic fracture typically causes immediate severe visual disturbance — double vision, glare, dramatically reduced acuity — from the disrupted refractive surface.

3. IOL Calcification / Opacification (Material Breakdown)
A distinct form of IOL breakdown involving progressive deposition of calcium salts or other material degradation within the IOL substance, causing clouding of the optic. This represents material degradation (breakdown of the IOL material itself) rather than physical fracture:

  • Hydrophilic acrylic IOL calcification — the most clinically significant form; calcium and phosphate precipitate within the hydrophilic acrylic matrix; may be triggered by:

    • Prior or concurrent gas tamponade (silicone oil, C3F8, SF6) used in retinal procedures

    • Anterior segment procedures exposing IOL to altered aqueous chemistry

    • Endothelial keratoplasty (DMEK/DSAEK) with BSS/air interface

    • Systemic metabolic factors

    • Spontaneous “sporadic” calcification of certain IOL batches (device-specific opacification — DSO)

    • Specific IOL design batches recalled or identified by manufacturers

  • Hydrophobic acrylic glistenings — microvacuoles of fluid within the IOL optic; usually mild; rarely requires IOL exchange

  • Silicone IOL opacification with silicone oil — silicone oil droplets adhere to silicone IOL material; causes severe visual obstruction; requires IOL exchange; a well-recognized reason to avoid silicone IOLs in retinal patients

Note

Opacified/calcified IOLs require exchange (CPT 66986) and are properly coded with T85.21XA as the structural/material breakdown of the IOL.

4. Posterior Capsule Bag Contraction / Capsular Phimosis
Capsular phimosis (fibrotic contraction of the anterior capsulorrhexis opening) can mechanically distort the IOL through unequal capsular tension — producing IOL tilt, decentration, or even haptic stress fracture in severe cases. When this process produces mechanical breakdown of the IOL itself, T85.21XA applies; when it produces displacement without breakdown, T85.22XA (displacement) or T85.29XA (other mechanical complication) may be more appropriate.

Clinical Presentation

Patients with IOL mechanical breakdown typically present with:

  • Decreased visual acuity — ranging from mild blur to severe vision loss depending on mechanism

  • Monocular diplopia / ghost images — from IOL tilt, decentration, or fractured optic surface

  • Glare and dysphotopsia — edge effects, optical aberrations from misaligned or fractured IOL

  • Progressive visual decline — gradual worsening in opacification/calcification breakdown; acute with fracture

  • Positive shadow / edge artifact — dysphotopsias from IOL decentration secondary to haptic fracture

  • Photophobia — from induced optical aberrations

Diagnosis

Slit-lamp biomicroscopy — the primary diagnostic tool:

  • Retroillumination — best method to visualize optic opacification, glistenings, calcification deposits

  • Direct and specular illumination — haptic visualization, tilt assessment

  • Dilated examination — full optic evaluation, posterior capsule assessment, posterior segment assessment

Scheimpflug imaging (Pentacam) — quantifies IOL tilt and decentration; useful for documenting material degradation

Optical coherence tomography (OCT anterior segment) — for detailed evaluation of IOL position, capsule contraction, haptic configuration

Ocular biometry (A-scan/optical biometry) — for IOL power calculation prior to IOL exchange

Specular microscopy — baseline endothelial cell count if IOL exchange is anticipated; corneal endothelial health affects surgical risk

7th Character Table

7th CharFull CodeDescriptionWhen to Use
AT85.21XAInitial encounterEvery encounter while actively receiving evaluation/treatment for IOL breakdown
DT85.21XDSubsequent encounterFollow-up visits during recovery after IOL exchange or repair; healing phase
ST85.21XSSequelaLate effects of the IOL breakdown (residual visual impairment, corneal changes)

Note

“A” throughout active treatment: Per ICD-10-CM Chapter 19 guidelines, the 7th character A is used for every encounter while the patient is actively receiving treatment for the IOL breakdown — including the initial discovery visit, pre-op visits, the surgical encounter (IOL exchange), and any early post-operative visits still within the active treatment context. The 7th character does NOT change to “D” until the patient transitions to routine healing/follow-up after the acute intervention is complete.

Code Structure / Code Tree

S00-T88    Injury, poisoning and certain other consequences of external causes
  └── T80-T88    Complications of surgical and medical care, NEC
        └── T85    Complications of other internal prosthetic devices, implants and grafts
              │    Excludes2: failure and rejection of transplanted organs/tissue (T86.-)
              │
              ├── T85.0    Mechanical complication of ventricular intracranial shunt
              ├── T85.1    Mechanical complication of implanted electronic stimulator of NS
              ├── T85.2    Mechanical complication of intraocular lens    ◄ SUBCATEGORY
              │     ├── T85.21    Breakdown (mechanical) of intraocular lens
              │     │     ├── T85.21XA    ... initial encounter    ◄ THIS CODE
              │     │     ├── [[T85.21XD]]    ... subsequent encounter
              │     │     └── [[T85.21XS]]    ... sequela
              │     ├── T85.22    Displacement of intraocular lens
              │     │     ├── [[T85.22XA]]    ... initial encounter
              │     │     ├── [[T85.22XD]]    ... subsequent encounter
              │     │     └── [[T85.22XS]]    ... sequela
              │     └── T85.29    Other mechanical complication of intraocular lens
              │           ├── [[T85.29XA]]    ... initial encounter
              │           ├── [[T85.29XD]]    ... subsequent encounter
              │           └── [[T85.29XS]]    ... sequela
              ├── T85.3    Mechanical complication of other ocular prosthetic devices
              │     ├── [[T85.31]]    Breakdown of prosthetic orbit of eye
              │     ├── [[T85.32]]    Displacement of prosthetic orbit of eye
              │     └── [[T85.39]]    Other mechanical complication, ocular prosthetic device
              ├── T85.4    Mechanical complication of breast prosthesis and implant
              ├── T85.5    Mechanical complication of gastrointestinal prosthetic devices
              ├── T85.6    Mechanical complication of other specified internal prosthetic devices
              ├── T85.7    Infection and inflammatory reaction due to prosthetic devices
              └── T85.8    Other specified complications of internal prosthetic devices

Information

T85.21XA vs T85.22XA vs T85.29XA — critical distinction: These three codes represent the three subtypes of IOL mechanical complication and are mutually exclusive for the same problem at the same time:

  • T85.21XA = IOL has structurally broken down — fractured, cracked, opacified/degraded material

  • T85.22XA = IOL is intact but has moved out of position — dislocated, subluxated, displaced

  • T85.29XA = Other mechanical problem — decentration, subluxation, rotation of toric IOL, other issues not fitting breakdown or displacement

Includes / Excludes Notes

Includes (T85.2 — Mechanical Complication of IOL)

  • Physical fracture of the IOL optic or haptic(s)

  • IOL material opacification or calcification (material breakdown/degradation)

  • IOL haptic fracture at the haptic-optic junction

  • Intraoperative IOL fracture during insertion, exchange, or repositioning

  • Late spontaneous IOL material failure (including hydrophilic acrylic calcification, silicone oil adherence to silicone IOL)

  • Any mechanical failure of the IOL device structure itself

Excludes1 at T85.21 (Mutually Exclusive — Do Not Code Together)

CodeDescriptionReason
Z96.1Presence of intraocular lens (pseudophakia)Z96.1 = IOL functioning normally (status code); T85.21XA = IOL is broken; these are mutually exclusive for the SAME eye at the SAME encounter

After successful IOL exchange: Once T85.21XA is treated (IOL exchanged and new IOL placed), the patient returns to pseudophakic status. At future encounters after the complication is resolved, Z96.1 becomes the appropriate code again — T85.21XA is no longer applicable and Z96.1 is no longer excluded.

Excludes2 at T85 Category (Can Code Together When Both Present)

CodeDescriptionCan Code With T85.21XA?
T86.-Failure and rejection of transplanted organs and tissueYes — if concurrent transplant complication present
H26.4-Secondary/posterior capsular opacificationYes — PCO can coexist with IOL breakdown; code both if both documented
H59.03-CME following cataract surgeryYes — if CME coexists with IOL mechanical complication

Code Also Instructions

Per T85 category instructional notes:

  • Code also any retained foreign body (Z18.-) if a fragment of the broken IOL remains in the eye

  • Code also any associated ocular injury or complication when concurrently present

HCC (Hierarchical Condition Category) Mapping

T85.21XA does NOT map to a CMS-HCC in any current risk adjustment model.

HCC ModelHCC AssignmentRAF Impact
CMS-HCC Model V28Not assignedNo RAF
RxHCC ModelNot assignedNo RAF
HHS-HCC (ACA Marketplace)Not assignedNo RAF

Risk adjustment note:

While T85.21XA carries no direct HCC weight, the underlying conditions that led to the IOL breakdown may carry HCC weight. For example, a patient whose hydrophilic IOL calcified following silicone oil tamponade for a retinal detachment has concurrent retinal disease codes that DO carry HCC weight. Accurate coding of all concurrent ocular pathology is essential for complete RAF capture.

MS-DRG Mapping (Inpatient)

IOL mechanical breakdown is almost exclusively managed outpatient or in the ASC setting. Inpatient admission is rare and occurs only when significant concurrent ocular pathology, systemic comorbidities, or complex combined surgical procedures require inpatient care.

CC/MCC Status

Per CMS MS-DRG v41:

  • T85.21XA — review current IPPS tables for CC designation; note that T85.22XA (displacement) and T85.29XA (other mechanical complication) are designated as CC in the CMS MS-DRG system

  • T85.22XA — CC (confirmed in v41.1)

  • T85.29XA — CC (confirmed in v41.1)

Always verify CC/MCC status against the current fiscal year IPPS MS-DRG definitions table, as CC/MCC designations can change with annual IPPS updates. The T85.2x family carries CC weight for the displacement and other mechanical complication codes — verify T85.21XA designation in the current version.

Inpatient DRG Groups (When Admitted)

MS-DRGDescriptionTrigger
116Intraocular Procedures with CC/MCCIOL exchange (OR procedure) performed inpatient + CC/MCC present
117Intraocular Procedures without CC/MCCIOL exchange performed inpatient, no CC/MCC
124Other Disorders of the Eye with MCC or Thrombolytic AgentT85.21XA as medical PDx + MCC
125Other Disorders of the Eye without MCCT85.21XA as medical PDx, no MCC

MDC: MDC 02 — Diseases and Disorders of the Eye

CPT Procedure Codes (Commonly Associated)

T85.21XA drives a specific set of surgical and diagnostic CPT codes. Because the IOL is structurally broken, the primary intervention is typically IOL removal and exchange or removal only.

Diagnostic Evaluation

CPTDescriptionwRVU (approx.)Notes
92014Comprehensive ophthalmological exam, established1.50Evaluation of IOL breakdown; detailed slit-lamp, retroillumination
92012Intermediate ophthalmological exam, established0.97Follow-up evaluation
92004Comprehensive ophthalmological exam, new patient2.67New patient referral for IOL complication evaluation
92132OCT anterior segment0.58IOL tilt, decentration, capsular contraction evaluation
92134OCT posterior segment0.58Rule out concurrent retinal pathology
76519Ophthalmic biometry (optical coherence biometry)0.77IOL power calculation prior to exchange
92136Ophthalmic biometry with intraocular lens power calculation1.36Optical biometry with IOL formula calculation
92235Fluorescein angiography1.10If concurrent CME or retinal pathology suspected

Primary Surgical Procedure — IOL Exchange (CPT 66986)

CPT 66986 is the primary surgical code for IOL exchange and is the procedure most directly supported by T85.21XA as the primary diagnosis.

CPTDescriptionwRVU (approx.)Assistant Allowed?Global Period
66986Exchange of intraocular lens~14.56No90 days

CPT 66986 — Detailed Guidance:

CPT 66986 describes the removal of a previously implanted IOL and insertion of a new IOL in the same surgical session. It applies when:

  • The original IOL has a mechanical complication (T85.21XA, T85.22XA, T85.29XA)

  • The IOL is being exchanged for clinical reasons (incorrect power, lens opacification, haptic fracture, dislocation)

  • Both removal of the old IOL and insertion of the new IOL occur in the same operative session

Modifier -78 requirement during global period: If the IOL exchange occurs within the 90-day global period of the original cataract surgery (CPT 66984 or 66982), Modifier -78 (unplanned return to the OR for a related procedure during the global period) must be appended to CPT 66986. Modifier -78 reduces reimbursement to the intraoperative component only (typically 70% of the procedure’s allowed amount) because the pre- and post-operative components are included in the global period of the original surgery.

T85.21XA for 66986 vs. T85.22XA: The specific T85.2x code reported with CPT 66986 should reflect the documented mechanism. When the IOL is being exchanged because it is broken/opacified → T85.21XA. When it is being exchanged because it is dislocated → T85.22XA. When being exchanged for another mechanical reason → T85.29XA. Accurate code-procedure linking is essential for claim integrity and clean claim processing, particularly for Medicare NCD compliance.

IOL Removal Without Exchange

When the IOL is removed but no new IOL is placed in the same session (leaving the patient aphakic or planning a secondary IOL at a later date):

CPTDescriptionwRVU (approx.)Assistant Allowed?Notes
65920Removal of implanted material, anterior segment of eye~8.45NoIOL removal from anterior chamber / capsular bag — for anterior segment IOL removal
67121Removal of implanted material, posterior segment; intraocular~12.71NoIOL removal from the vitreous cavity — for IOLs that have dropped or migrated posteriorly

65920 vs 67121 — location determines the code: CPT 65920 is used when the IOL is removed from the anterior segment (capsular bag, ciliary sulcus, anterior chamber). CPT 67121 is used when the IOL (or a fragment) must be retrieved from the posterior segment / vitreous cavity. When a broken IOL haptic has migrated into the vitreous, 67121 is the appropriate code for that retrieval.

Secondary IOL Implantation (After Aphakia Created by Removal)

When a new IOL is inserted at a separate encounter after the broken IOL was removed:

CPTDescriptionwRVU (approx.)Assistant Allowed?Notes
66985Insertion of intraocular lens prosthesis (secondary implant), not associated with concurrent cataract removal~14.33NoSecondary IOL after aphakia established from IOL removal

Concurrent Vitrectomy Procedures

When IOL mechanical breakdown (particularly posterior dislocation of IOL fragments) requires concurrent vitreoretinal intervention:

CPTDescriptionwRVU (approx.)Assistant Allowed?Notes
67036Pars plana vitrectomy (PPV), anterior approach~21.46NoPPV for retrieval of IOL/haptic fragments in vitreous
67108Repair of retinal detachment; with vitrectomy~28.27YesIf concurrent RD with IOL dislocation/breakdown
67041Vitrectomy with membrane peel~17.60YesIf ERM concurrent with IOL complication

66986 + 67036 bundling consideration: CPT 66986 (IOL exchange) and CPT 67036 (PPV) can be reported together when medically necessary — they are not bundled under the NCCI (National Correct Coding Initiative) when performed for separate indications in the same session. Link 66986 to T85.21XA and 67036 to the posterior segment diagnosis (e.g., H43.392 vitreous opacities, or H33.- retinal detachment).

Scleral Fixation / Suture Fixation of New IOL

When the IOL exchange requires a suture-fixated or glued IOL due to lack of capsular support:

CPTDescriptionwRVU (approx.)Assistant Allowed?Notes
66682Suture of iris, ciliary body; retrieval of suture through small incision~9.25NoSuture fixation/retrieval of IOL suture — iris fixation technique
No specific CPTScleral-fixated IOL (Gore-Tex suture, flanged haptic technique)Report 66985 or 66986 with appropriate modifiersVerify per payerNo specific separate CPT for scleral fixation approach; technique included in IOL implantation code

Ophthalmic Biometry for IOL Power Calculation

CPTDescriptionwRVU (approx.)Notes
76519Ophthalmic biometry (A-scan only) with IOL power calculation0.77For IOL power calc pre-exchange
92136Ophthalmic biometry, optical coherence1.36Optical coherence biometry (IOLMaster, Lenstar)

T85.21XA as covered diagnosis for biometry: CMS Billing and Coding Article for Ophthalmic Biometry for IOL Power Calculation (A56549) explicitly lists T85.21XA as a covered diagnosis supporting biometry (CPT 76519, 92136). This is an important payer compliance point — the biometry is not cosmetic and is medically necessary to calculate the correct power for the replacement IOL.

Specular Microscopy (Pre-Surgical Endothelial Evaluation)

CPTDescriptionwRVU (approx.)Notes
92286Specular microscopy with or without photography0.62Endothelial cell count before IOL exchange; particularly important for complex ACIOL or sutured IOL exchanges where corneal endothelium is at risk

E/M and Consultation Services

CPTDescriptionwRVU (approx.)Notes
99205New patient office visit, high complexity3.50New referral for IOL complication evaluation
99215Established patient, high complexity2.80Complex IOL complication management
99213-99214Office visit, established, low-moderate complexity0.97-1.50Routine post-exchange follow-up

Assistant Surgeon Summary

ProcedureAssistant Allowed?
IOL exchange (66986)No
IOL removal, anterior (65920)No
IOL removal, posterior (67121)No
Secondary IOL implantation (66985)No
Pars plana vitrectomy (67036)No
PPV with membrane peel (67041)Yes
PPV with retinal detachment repair (67108)Yes
Suture fixation (66682)No
All diagnostic servicesNo

Coding Examples

Example 1 — Broken IOL Haptic Discovered Post-Op Day 1, IOL Exchange During Global Period

Clinical Scenario:
A 68-year-old female undergoes uncomplicated right eye phacoemulsification with trifocal IOL implantation (CPT 66984-RT). On post-op day 1, she reports monocular diplopia and glare OD. Slit-lamp examination reveals a broken superior haptic of the trifocal IOL, causing inferior decentration of the optic OD. She is returned to the OR on post-op day 2 for IOL exchange (66986). The original IOL is explanted and a new trifocal IOL is implanted.

ICD-10-CM:

  • T85.21XA — Breakdown (mechanical) of intraocular lens, initial encounter (IOL haptic fracture — the breakdown diagnosis)

CPT (IOL exchange visit):

  • 66986-RT-78 — Exchange of intraocular lens, right eye, with Modifier -78 (unplanned return to OR during 90-day global period of 66984)

Modifier -78 is mandatory when IOL exchange occurs within the 90-day global period of the original cataract surgery. Without Modifier -78, the claim will be denied as it falls within the global period of the primary procedure.

Example 2 — Hydrophilic IOL Calcification, IOL Exchange After 3 Years

Clinical Scenario:
A 74-year-old male had bilateral cataract surgery 3 years ago with hydrophilic acrylic IOLs implanted. He presents with progressive blurring OD over 6 months. Slit-lamp retroillumination shows dense crystalline opacification throughout the optic of the right IOL. Diagnosis: hydrophilic acrylic IOL opacification/calcification (material breakdown), right eye. IOL exchange with hydrophobic acrylic IOL is performed.

ICD-10-CM:

  • T85.21XA — Breakdown (mechanical) of intraocular lens, initial encounter (IOL material opacification — material breakdown of the IOL device)

CPT (pre-surgical evaluation visit):

  • 92014-RT — Comprehensive ophthalmological exam, established patient

  • 92132-RT — OCT anterior segment (IOL opacification documentation)

  • 92136 — Ophthalmic biometry with IOL power calculation

CPT (surgical encounter):

  • 66986-RT — Exchange of intraocular lens, right eye (no Modifier -78 — original surgery > 90 days prior)

Example 3 — Silicone IOL with Silicone Oil Adherence, Combined PPV and IOL Exchange

Clinical Scenario:
A 55-year-old male with a history of retinal detachment repair OS and silicone oil tamponade has a silicone IOL OS from prior cataract surgery. He presents with dense visual obstruction OS from silicone oil droplets coating his silicone IOL. Combined pars plana vitrectomy (silicone oil removal) and IOL exchange (silicone IOL → hydrophobic acrylic) is performed.

ICD-10-CM:

  • T85.21XA — Breakdown (mechanical) of intraocular lens, initial encounter (silicone IOL breakdown from oil adherence — material failure)

  • H43.20 — Crystalline deposits in vitreous body, unspecified eye (or appropriate silicone oil residual code)

CPT:

  • 66986-LT — Exchange of intraocular lens, left eye (for the IOL exchange; linked to T85.21XA)

  • 67036-LT — Pars plana vitrectomy (for silicone oil removal; linked to vitreous/retinal diagnosis)

Two CPT codes — two different diagnoses: Link 66986 to T85.21XA and 67036 to the vitreous/retinal diagnosis. This preserves claim integrity and ensures each procedure is tied to its specific medical necessity diagnosis.

Example 4 — Broken IOL During Cataract Surgery (Intraoperative Complication)

Clinical Scenario:
A 70-year-old male undergoes right eye cataract surgery. During IOL injection through the cartridge, the haptic of the multifocal IOL fractures inside the injector. The surgeon removes the damaged IOL and implants a replacement IOL in the same session.

ICD-10-CM:

  • H26.011 — Infantile and juvenile cortical, lamellar, or zonular cataract, right eye (or appropriate cataract code — the reason for the original surgery)

  • T85.21XA — Breakdown (mechanical) of intraocular lens, initial encounter (intraoperative IOL fracture)

CPT:

  • 66984-RT — Extracapsular cataract removal with IOL, routine (or 66982 if complex criteria met — the primary procedure)

No separate CPT for IOL replacement in same session: When the IOL fractures intraoperatively and is immediately replaced with a new IOL in the same session, the IOL exchange is included in the cataract CPT code (66984/66982) — there is no separate CPT for the replacement. T85.21XA documents the intraoperative complication for the record.

Example 5 — IOL Fragment in Vitreous, PPV for Retrieval

Clinical Scenario:
A 78-year-old female presents with sudden vision decrease OD. Examination reveals a dislocated and broken IOL with a free haptic fragment in the vitreous cavity OD. The patient is taken to the OR for pars plana vitrectomy with retrieval of the posterior IOL fragments and IOL exchange with scleral-fixated IOL.

ICD-10-CM:

  • T85.21XA — Breakdown (mechanical) of intraocular lens, initial encounter (broken IOL with fragment)

  • T85.22XA — Displacement of intraocular lens, initial encounter (concurrent dislocation of the main IOL body — if both breakdown and displacement are documented, both T85.21XA and T85.22XA may be reported)

CPT:

  • 67036-RT — Pars plana vitrectomy (for vitreous work and posterior fragment retrieval)

  • 67121-RT — Removal of implanted material, posterior segment (for IOL fragment in vitreous)

  • 66985-RT — Insertion of IOL prosthesis, secondary implant (new IOL placement after aphakia established)

Example 6 — Subsequent Encounter for Routine Post-Exchange Follow-Up

Clinical Scenario:
Same patient as Example 2. Returns 3 weeks post-IOL exchange OD for routine post-operative follow-up. Visual acuity 20/25, IOL well centered, no complications.

ICD-10-CM:

  • T85.21XD — Breakdown (mechanical) of intraocular lens, subsequent encounter (7th character changes to “D” — now in the healing/recovery phase, active treatment complete)

  • Z96.1 — Presence of intraocular lens (pseudophakia — Z96.1 becomes applicable again once the new IOL is confirmed to be functioning normally)

7th character transition A → D: The switch from “A” to “D” occurs when active treatment for the IOL breakdown is complete (IOL exchange performed) and the patient enters the routine recovery/monitoring phase. At this follow-up visit, T85.21XD reflects the post-treatment status. Z96.1 is again appropriate because the new IOL is functioning normally — the Excludes1 applies only when the IOL is actively broken/mechanically compromised.

Key Coding Pitfalls & Tips

  • “XX” placeholders are mandatory. The complete code is always T85.21XA — never T85.21A. The double-X occupies positions 4 and 5 and is structurally required for the code to be valid. Omitting the XX creates an invalid, non-billable code that will reject.

  • T85.21XA and Z96.1 are Excludes1 — never code together for the same eye at the same encounter. Z96.1 (IOL present, functioning normally) and T85.21XA (IOL broken) are mutually exclusive states. However, once the broken IOL is exchanged and the new IOL is functioning, Z96.1 is again appropriate at subsequent visits.

  • T85.21XA vs T85.22XA vs T85.29XA — match the code to the mechanism. Broken/opacified/fractured IOL → T85.21XA. Dislocated/displaced IOL (intact) → T85.22XA. Other mechanical problem (decentration, rotation) → T85.29XA. Do not default to T85.29XA for all IOL complications — specificity matters for claim integrity and MPFS compliance.

  • Modifier -78 is required within the global period. If IOL exchange (66986) is performed within 90 days of the original cataract surgery (66984, 66982), Modifier -78 must be appended. Failure to append -78 will result in denial as the claim falls within the global period of the primary surgery.

  • T85.21XA supports biometry CPT codes. CMS explicitly lists T85.21XA as a covered diagnosis for ophthalmic biometry (76519, 92136). Always include T85.21XA on the biometry order/claim when IOL exchange planning is the indication.

  • Link each CPT to its specific diagnosis in combination procedures. When 66986 and 67036 are performed together, link 66986 to T85.21XA (or T85.22XA) and 67036 to the retinal/vitreous diagnosis. Mismatched code-procedure linking is a primary cause of claim denials in combined lens-vitreoretinal surgery.

  • Intraoperative IOL fracture is coded T85.21XA. When an IOL breaks intraoperatively during insertion (a known complication of trifocal and EDOF IOL delivery systems), T85.21XA is appropriate as an additional code on the surgical encounter even though the broken IOL was immediately replaced in the same session.

  • Material breakdown (opacification, calcification) is T85.21XA. IOL opacification, calcification, and material degradation represent breakdown of the IOL device material — not displacement. Always use T85.21XA for these material failure presentations, not T85.22XA or T85.29XA.

CodeDescription
T85.21XDBreakdown of intraocular lens, subsequent encounter
T85.21XSBreakdown of intraocular lens, sequela
T85.22XADisplacement of intraocular lens, initial encounter (IOL intact but dislocated)
T85.22XDDisplacement of intraocular lens, subsequent encounter
T85.22XSDisplacement of intraocular lens, sequela
T85.29XAOther mechanical complication of IOL, initial encounter (decentration, other)
T85.29XDOther mechanical complication of IOL, subsequent encounter
T85.79XAInfection and inflammatory reaction due to other internal prosthetic devices, initial
Z96.1Presence of intraocular lens (pseudophakia) — Excludes1 with T85.21XA during active complication
H26.41Soemmering’s ring (capsular opacification — distinct from IOL breakdown)
H26.491PCO, right eye (secondary cataract — distinct from IOL material breakdown)
H26.492PCO, left eye
H26.493PCO, bilateral
H59.031CME following cataract surgery, right eye (may coexist with T85.21XA)
H59.032CME following cataract surgery, left eye
H27.01Aphakia, right eye (post-IOL removal without replacement)
H27.02Aphakia, left eye
H33.00-Retinal detachment (may coexist; concurrent vitreoretinal procedure needed)
H43.392Other vitreous opacities (use with 67036 for concurrent PPV)
T85.310ABreakdown of prosthetic orbit, right eye (separate from IOL)
Z98.41Cataract extraction status, right eye
Z98.42Cataract extraction status, left eye

Last Reviewed: 2026-02-18 | Source: ICD-10-CM FY2025, CMS MPFS, CMS MS-DRG v42.0, CMS Billing and Coding: Ophthalmic Biometry for IOL Power Calculation (A56549), Retina Today Coding References, Cataract & Refractive Surgery Today, AAPC Ophthalmology Coding Alert, ICD-10-CM Official Coding Guidelines FY2026

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