65855

👩🏾‍⚕️CPT Code 65855: Documentation & Billing Guide

Trabeculoplasty by laser surgery, one or more sessions (defined treatment series)

Last Updated: February 2026
Status: 2025 Medicare Fee Schedule Compliant
Specialty Tags: ophthalmology glaucoma laser surgical CPT ophthalmology

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Quick Reference Table

Element	Details
CPT Code	65855
Code Type	Surgical Procedure - Ophthalmology/glaucoma
Procedure Type	trabeculoplasty by laser surgery, one or more sessions (defined treatment series)
Global Period	010 (Minor procedure, 10-day postoperative period)
Work RVU (2025)	3.00
PE RVU (2025, Non-Facility)	4.04
PE RVU (2025, Facility)	Not separately available (facility-based)
Malpractice RVU (2025)	0.23
Total RVU (2025, Non-Facility)	7.27
Medicare Payment (Non-Facility, 2025)	~$235.16
Medicare Payment (Facility, 2025)	~$196.99
2025 Conversion Factor	$32.35
Estimated Commercial Insurance	$80 0- 2,500+
Medicaid Range (State-Dependent)	$150 - 400
Procedure Time	15-30 minutes
Place of Service	Office (11), Outpatient Hospital (22), ASC (24)
Typical Specialty	Ophthalmology, Optometry (10 states)

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📋 SHORT DEFINITION

CPT 65855 describes trabeculoplasty by laser surgery - a minimally invasive laser-based procedure that treats the trabecular meshwork (eye’s natural drainage system) to reduce intraocular pressure (IOP) in patients with glaucoma. The procedure encompasses one or more treatment sessions performed within a defined treatment series. Both Argon Laser Trabeculoplasty (ALT) and Selective Laser Trabeculoplasty (SLT) are coded with 65855 (CPT is laser-agnostic).

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LONG DEFINITION

Overview

CPT 65855 represents a surgical intervention for elevated intraocular pressure (IOP) by laser-induced modifications to the trabecular meshwork - the microscopic drainage channels at the eye’s drainage angle. By thermally or ablatively treating these channels, laser trabeculoplasty aims to improve aqueous humor outflow and reduce IOP.

Key distinctions:

• Argon Laser Trabeculoplasty (ALT): Traditional thermal laser (argon) that creates scarring to increase outflow
• Selective Laser Trabeculoplasty (SLT): Newer selective approach using Nd:YAG laser; targets melanin-containing cells with less tissue damage
• CPT 65855 encompasses both - same code, different laser technology
• “One or more sessions” → Multiple treatments within the defined series count as one CPT code

Clinical Indications

1. Open-Angle Glaucoma (OAG) - Primary or Secondary

• Elevated intraocular pressure (typically >21 mmHg) despite medical therapy
• Progressive optic nerve damage or visual field loss
• Patient intolerant of topical medications (side effects, compliance issues)
• Medications contraindicated (systemic or ocular reasons)
• Primary glaucoma therapy increasingly considered in recent guidelines as an option before surgery

2. Ocular Hypertension

• Elevated IOP (24 mmHg or greater) with risk factors:
  • Vertical cup-disc ratio ≥0.8
  • Corneal thickness ≤555 microns
  • Sociogenic risk factors
• No current optic nerve damage but high-risk profile

3. Failed Medical Therapy

• Topical medications ineffective in lowering IOP to target pressure
• Patient noncompliance with eye drops
• Side effects (systemic absorption, local irritation, allergic reactions)
• Contraindicated medications due to medical comorbidities

4. Pigmentary or Pseudoexfoliative Glaucoma

• Pigment dispersion or pseudoexfoliation deposits at trabecular meshwork
• Often respond particularly well to SLT

5. Glaucoma Secondary to Eye Trauma

• Post-traumatic IOP elevation from angle damage or inflammation
• Laser trabeculoplasty as alternative to filtering surgery

6. Steroid-Induced Glaucoma

• IOP elevation from chronic topical or systemic steroid use
• Laser intervention when steroids cannot be discontinued

Procedure Technique

Patient Preparation:

• Baseline intraocular pressure measurement (Goldmann applanation tonometry, rebound tonometry, or other method)
• Gonioscopy: Visualization of the drainage angle and trabecular meshwork to assess:
  • Angle grade (Shaffer grading: 0-4)
  • Pigmentation of trabecular meshwork
  • Previous laser damage (if repeat treatment)
  • Absence of angle closure (critical - contraindication to trabeculoplasty)
• Visual fields: Baseline documentation (if glaucoma already diagnosed)
• Photography: Optic nerve head imaging for baseline
• Informed consent: Discussion of indications, risks (transient IOP spike, inflammation, failure, repeat treatment), benefits
• Topical anesthesia: Proparacaine or similar
• Miotic drop (optional): Pilocarpine sometimes used pre-procedure to enhance angle visualization
• Anti-inflammatory pre-medication: Often given pre- and post-op to minimize inflammatory response

Equipment:

• Laser system:
  • Argon laser: Multi-wavelength (488 nm, 514 nm lines) or argon-krypton
  • Nd:YAG Laser: 1064 nm wavelength (for SLT)
  • Diode laser: Alternative option (less commonly used for TLP specifically)
• Gonioscope: For direct visualization of trabecular meshwork during laser application
• Laser delivery system: Contact or non-contact delivery
• Cooling system (for some lasers)
• Indirect goniolens or direct gonioscope (typically Goldmann, Ritch, or similar)

Operative Technique:

Step 1: Patient Positioning & Angle Visualization

• Patient seated at laser slit lamp or lying supine (depending on equipment)
• Topical anesthesia applied
• Gonioscope placed on cornea with coupling gel
• Angle structures identified and brought into clear view
• Trabecular meshwork located (between Schwalbe’s line and ciliary body band)
• Nasal angle typically treated first, then temporal, or entire 360° in one session

Step 2: Laser Parameters & Treatment Application

For Argon Laser Trabeculoplasty (ALT):

• Spot size: 50 μm
• Exposure time: 0.1-0.2 seconds (typically)
• Power: 400-1000 mW (titrated to achieve appropriate burn)
• Treatment endpoint: “Blanching” or mild whitening of trabecular meshwork
• Spacing: Approximately one spot-width apart, typically 360° (or 180° for partial treatment)
• Total spots: Usually 50-100 spots per session
• Sessions: May be performed 360° in one sitting or split into two 180° sessions

For Selective Laser Trabeculoplasty (SLT):

• Spot size: 400 μm
• Wavelength: 1064 nm (Nd:YAG)
• Pulse duration: ~3 nanoseconds
• Energy: 0.6-1.2 mJ (titrated)
• Treatment endpoint: “Microbubble” formation at trabecular meshwork
• Spacing: Similar to ALT
• Coverage: Typically 360° but can be 180° in initial treatment
• Sessions: Usually single treatment 360° or 180° with possibility of repeat treatment in 3+ months if needed

Step 3: Post-Laser Assessment

• IOP spike monitoring (may rise immediately post-op)
• Angle inflammation assessed
• Gonioscope removed
• Anterior chamber examined for:
  • Hyphema (blood in anterior chamber - usually minimal)
  • Inflammation level
  • Corneal abrasion (rare)

Step 4: Medications Administered

• Topical anti-inflammatory: Prednisolone acetate 1% or dexamethasone 0.1% (frequency varies: 4× daily to qid for 1-2 weeks post-op)
• Intraocular pressure-lowering medication: Often applied same day if significant pressure spike anticipated:
  • Apraclonidine 1% (if not allergic - suppresses IOP spike)
  • Pilocarpine (less commonly used now)
  • Timolol or other aqueous suppressant if needed

Post-Operative Course

Immediate Post-Op (Same Day):

• Topical antibiotics: Ofloxacin, ciprofloxacin, or similar (variable - some practitioners omit)
• Anti-inflammatory drops: Prednisolone 1% four times daily
• Pressure-lowering agents: Continue/start as needed to manage IOP spike
• Activity: Rest, avoid strenuous activity

Days 1-7:

• Follow-up visit: Typically day 1 or within 3 days to assess IOP response and inflammation
• Continuation of topical anti-inflammatory (usually 1-2 weeks total)
• IOP checks: Multiple visits if needed to ensure adequate pressure control
• Assess for complications: Iritis, hyphema, corneal abrasion

Days 7-10 (Global Period Extends 10 Days):

• Anti-inflammatory taper as inflammation resolves
• IOP stabilization expected
• Assessment of treatment efficacy (may not be full effect until 3-6 weeks post-op)

Longer-Term Follow-Up (Weeks to Months):

• Visual field testing: Baseline for comparison (often performed several weeks post-op to allow IOP stabilization)
• Optic nerve photography: For progression assessment
• IOP target: Determined based on glaucoma stage and risk factors (typically 20% reduction target)
• Repeat treatment: If IOP reduction inadequate after 3-6 months, repeat trabeculoplasty or escalation to other modalities (additional drops, other laser procedures, filtering surgery) considered

Expected Outcomes:

• Success rate: 50-80% achieve target IOP reduction (definitions vary by study)
• IOP reduction: Average 25-50% in responsive cases
• Durability: Effect may last 3-5 years; repeat treatment possible
• Duration to full effect: 3-6 weeks post-op

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KEY DISTINCTIONS - Similar CPT Codes

Code	Description	Laser Type	RVU (Work)	Mechanism
65855	Trabeculoplasty by laser surgery	ALT or SLT	3.00	Trabecular meshwork treatment
66761	YAG laser capsulotomy/hyaloidotomy	YAG	1.50	Posterior capsule disruption
66762	YAG laser cyclophotocoagulation	YAG	2.05	Ciliary body ablation (higher risk)
66821	Discission of secondary membrane	Argon/YAG	1.75	Membrane disruption (not TLP)
66174	Trabeculostomy ab interno (MIGS)	Mechanical/laser	4.50	Internal drainage channel creation

Critical Distinctions:

• 65855 vs 66761: 65855 treats trabecular meshwork; 66761 treats posterior capsule (different anatomic target)
• 65855 vs 66762: 65855 targets drainage angle; 66762 ablates ciliary body (more destructive, for advanced glaucoma)
• 65855 vs 66174: 65855 is thermal/photoacoustic laser; 66174 is mechanical/endoscopic trabeculostomy (MIGS - minimally invasive glaucoma surgery)
• ALT vs SLT (both 65855): Same CPT code; SLT more selective, less thermal damage, possibly repeatable

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RVU BREAKDOWN - 2025

Work RVU Components

Component	Value	Represents
Work RVU	3.00	Physician skill, laser application, angle manipulation, decision-making
PE RVU (Non-Facility)	4.04	Laser equipment, gonioscope, medications, supplies, support staff
PE RVU (Facility)	Included	Hospital/ASC provides equipment and staff
Malpractice RVU	0.23	Malpractice insurance (minor-to-moderate risk)
TOTAL (Non-Facility)	7.27	Sum of all components

Conversion to Dollar Amount (2025 Medicare)

Formula: RVU × Conversion Factor (CF) × Geographic Practice Cost Index (GPCI) = Payment

2025 CF: $32.35

Non-Facility Calculation (GPCI = 1.0):

• Work: 3.00 × $32.35=\ast \ast$97.05**
• PE: 4.04 × $32.35=\ast \ast$130.70**
• MP: 0.23 × $32.35=\ast \ast$7.44**
• Total = $235.16

Facility Calculation (varies by MAC):

• Typically $196.99 (Medicare average for facility-based ASC/hospital)
• PE RVU reduced due to facility providing equipment/staff

Real-World Ranges (2025)

Setting	Range	Notes
Non-Facility (Office)	$220 - 250	Varies by GPCI; regional adjustment
Facility (Hospital/ASC)	$180 - 210	Lower due to facility PE RVU
Commercial Insurance	$800 - 2,500+	3-10× Medicare; highly payer-dependent
Medicaid	$150 - 400	State-dependent; often 50-80% of Medicare
Self-Pay Cash	$400 - 800	Office practices typically charge this range

2024 vs 2025 Comparison

Metric	2024	2025	Change
Work RVU	3.00	3.00	—
PE RVU (Non-Fac)	4.04	4.04	—
CF	$33.29	$32.35	-2.83%
National Average (Non-Fac)	~$241.92	~$235.16	-2.83%

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GLOBAL PERIOD - 010 (Minor Procedure, 10-Day)

Status: 010 - 10-Day Global Period

What This Means:

• 65855 includes 10 days of postoperative care (day of surgery + 9 following days)
• Pre-operative care (evaluation, gonioscopy, consent) is included in the global package
• Post-operative visits within 10 days related to the procedure are included and non-billable
• Exception: Unrelated E/M on same day or during global period can be billed with -24 modifier if separately identifiable reason

Billing Implications:

• Cannot bill office visit (99213-99215) for post-op check within 10 days (already included in global)
• Can bill related laser procedures during global with -58 modifier (staged/planned/more extensive procedure)
• Can bill unrelated procedures same day with appropriate modifiers (-59, -24)
• No repeat trabeculoplasty within 10 days unless distinctly separate (rare, requires -58/-79)

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DOCUMENTATION REQUIREMENTS - CRITICAL

Pre-Procedure Assessment

History - Must Document:

• Indication for procedure: Why is laser trabeculoplasty medically necessary TODAY?
  • Failed medical therapy? (List medications tried, duration, adverse effects)
  • Medication intolerance or contraindication?
  • Glaucoma type (primary open-angle, secondary, ocular hypertension)?
  • Progressive vision loss or optic nerve damage documented?
  • IOP readings over time?
• Current medications: Topical and systemic glaucoma medications, compliance issues
• Glaucoma history: Duration of diagnosis, prior treatments (medications, laser, surgery)
• Pertinent eye history: Previous ocular surgery, angle-closure risk, pseudoexfoliation, pigmentary glaucoma?
• Systemic diseases: Diabetes, hypertension, autoimmune conditions (affect healing/inflammation risk)
• Allergies: Topical medications, contrast agents, latex

Physical Examination - Must Document:

• Visual acuity: Current (recorded with or without correction)
• Intraocular pressure: Both eyes, method of measurement (applanation, rebound, etc.)
• Gonioscopy findings - CRITICAL:
  • Angle grade (Shaffer grading 0-4, both eyes)
  • Trabecular meshwork appearance: Pigmentation (light/moderate/heavy), scarring, anterior synechiae
  • Prior laser damage: Present? Previous 360° treatment or partial?
  • Angle-closure risk assessment: Narrow angle ruled out?
  • Iris/lens position: Normal or abnormal?
• Optic nerve assessment: Cup-disc ratio, notching, hemorrhages, pallor, rim appearance
• Fundus examination: General health of posterior segment

Baseline Imaging/Testing:

• Visual fields: Baseline 24-2 or 30-2 visual field (if prior VF available, comparison)
• Optic nerve photography: Stereoscopic disc photos (for baseline)
• OCT optic nerve head: If available/performed (quantifies cup-disc ratio, rim area)
• Anterior segment imaging: OCT or other imaging of angle (optional, increasingly used)

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Intra-Operative Documentation - CRITICAL

Pre-Laser Assessment:

• Visual acuity: Documented
• Intraocular pressure (baseline): Measured immediately pre-op
• Gonioscopy findings (pre-laser):
  • Angle grade: Right and left
  • Trabecular meshwork: Pigmentation degree, scarring
  • Laser target areas identified
  • Contraindications ruled out (narrow angles)

Laser Treatment Parameters - MUST DOCUMENT:

For Argon Laser Trabeculoplasty (ALT):

• Laser type: Argon (wavelength, single-line vs multi-line)
• Spot size: 50 μm (standard)
• Exposure time: Duration per spot (e.g., 0.1 sec)
• Power range: Watts/milliwatts applied
• Burn grade/endpoint: Blanching, color change observed (1-4 scale typical)
• Treatment extent: 360° (full) vs 180° (half) vs partial (specify quadrants treated)
• Number of applications: Total spots applied (typically 50-100)
• Laterality: Right eye, left eye, or bilateral (with justification for bilateral)
• Complications during: Any difficulty (iris contact, bleeding, corneal touch), response to laser

For Selective Laser Trabeculoplasty (SLT):

• Laser type: Nd:YAG selective laser trabeculoplasty
• Wavelength: 1064 nm (confirm in note)
• Spot size: 400 μm
• Pulse duration: ~3 nanoseconds
• Energy level: Joules/millijoules per shot
• Endpoint: Microbubble formation observed (critical sign of appropriate treatment)
• Coverage: 360° or 180° (specify)
• Number of applications: Total shots
• Laterality: Right/left/bilateral with justification
• Ease of treatment: Any difficulty with visualization, angle access

Procedure Findings:

• Inflammatory response: None, mild, moderate, severe
• Hyphema: None vs present (grade if present)
• Corneal clarity: Clear, epithelial defect, abrasion
• IOP immediately post-laser: Measured (often rises transiently)
• Angle assessment post-laser: Inflammation level, hyphema presence

Complications During Procedure (if any):

• Corneal abrasion
• Hyphema
• Iris burns
• Inadequate visualization
• Angle closure precipitated (rare)
• Other: specify

Medications Instilled:

• Anti-inflammatory drops: Type, concentration, time instilled
• IOP-lowering agents: Apraclonidine, pilocarpine, or other - why used
• Antibiotics: Type (if used)

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Post-Operative Documentation

Immediate Post-Op (Recovery Phase):

• Patient tolerating procedure: Yes/discomfort level
• Anterior chamber reaction: Grade of inflammation (0-4+)
• IOP post-op: Measured before discharge (establish if spike occurred)
• Hyphema: Absence or grade
• Medications: Prescribed for post-op
• Anti-inflammatory: Type, concentration, frequency, duration
• IOP-lowering: List of agents, frequency
• Antibiotics: Type, frequency (if used)
• Discharge status: Alert, stable, able to go home safely
• Post-op instructions given: Rest, activity restrictions, when to call, follow-up timing

Post-Operative Visit Documentation (Day 1-3 Typically):

• Visual acuity: Measured
• Intraocular pressure: Both eyes, method
• Anterior chamber reaction: Inflammation level (improving/stable/worsening)
• Hyphema: Present/resolved
• Gonioscopy findings: Angle response to laser, if rechecked
• Assessment: Response to treatment, any complications
• Plan: Continue medications, follow-up schedule, further management

Follow-Up Visits (Weeks to Months Post-Op):

• Visual acuity: Recorded
• Intraocular pressure: Measurements showing trend
• Assessment of IOP reduction: Compare pre-op and post-op IOP
• Adequacy of pressure control: Target pressure met? Yes/no
• Optic nerve assessment: Any changes
• Visual field: If repeated (timing varies by practice)
• Plan for escalation: If adequate IOP reduction achieved - continue current therapy. If inadequate - consider additional treatments

Outcome Documentation - CRITICAL FOR COMPLIANCE:

• Success vs failure: Define threshold for “success” (e.g., ≥20% IOP reduction from baseline)
• Complications: None, transient elevation, persistent elevation, inflammation, other
• Need for repeat treatment: At what timeframe?
• Plan for non-responders: Escalation to additional medications, repeat laser, or filtering surgery

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COMMON MODIFIERS

Modifier	Description	Usage
-50	Bilateral Procedure	If bilateral trabeculoplasty same day; reimbursement = 150% of single-eye RVU
-RT/-LT	Right/Left Eye	HIGHLY RECOMMENDED; clarifies which eye treated (standard practice)
-22	Increased Procedural Services	If complexity substantially higher than typical (e.g., difficult gonioscopy, repeat treatment same day); requires documentation; may reduce reimbursement slightly
-52	Reduced Services	If procedure partially curtailed (rare; e.g., stopped after 180° when planned for 360°); justification required
-53	Discontinued Procedure	If stopped after anesthesia but before treatment commenced; requires justification
-58	Staged/Related Procedure	If repeat trabeculoplasty within 90 days (global period) as planned sequence; or if trabeculectomy performed during global for failed TLP; no reimbursement reduction
-79	Unrelated Procedure During Global	If unrelated eye procedure performed during 10-day global period of TLP; different diagnosis codes required
-24	Unrelated E/M During Global	If office visit for unrelated reason during 10-day global; apply to E/M code, not 65855
None	Standard Billing	Routine unilateral trabeculoplasty, no modifiers needed

Practical Notes:

• -50 vs -RT/-LT: Some payers prefer -50 for bilateral; others want -RT and -LT on separate lines. Verify payer rules pre-claim.
• -58 vs -79: -58 implies staged/planned; -79 implies unrelated. Wrong modifier → potential denial.
• Modifier stacking: Do not use -50 with -RT/-LT (redundant). Choose one approach per payer.

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MEDICARE RULES & POLICIES

1. Global Period - 10 Days

• 65855 has a 10-day global period (010 code)
• Pre-operative evaluation included (gonioscopy, consent, baseline IOP)
• Post-operative visits within 10 days for related care are included
• Unrelated E/M or procedures during global can be billed with appropriate modifiers

2. Bundling with Other Glaucoma Codes

• 65855 does NOT bundle with most other glaucoma codes (checked against CCI edits)
• Exception: Cannot bill 65855 with YAG capsulotomy (66761) or cyclophotocoagulation (66762) same day without strong clinical justification and -59 modifier (rare scenario)
• Trabeculectomy (66170/66172) during global of 65855: Use -58 modifier (staged procedure); no reimbursement reduction

3. Repeat Trabeculoplasty (Same Eye, Same Session vs Multiple Sessions)

• Same eye, same session (360°): Code once as 65855 (covers entire treatment)
• Same eye, staged (180° then 180° at different times): Second treatment within 90-day global: Use 65855-58 on second claim
• Same eye, later repeat (after global expires): Code separately as new 65855 (new global period starts)
• Both eyes, same session: Bilateral coding (65855-50 or 65855-RT + 65855-LT per payer preference)

4. Medically Necessary Criteria (Per CMS & Insurance Policies)

Medicare Coverage Typically Requires:

• Documented diagnosis: Open-angle glaucoma or ocular hypertension with risk factors
• Failed medical therapy: Evidence that topical medications were tried for adequate period (typically 3+ months minimum) and either:
  • Failed to achieve target IOP (define target IOP in chart)
  • Patient intolerant (side effects, compliance issues)
  • Contraindicated (systemic or ocular reasons)
• OR Primary therapy: Increasingly, SLT recognized as primary option without mandatory medication failure (check payer policy)
• Baseline testing: Visual fields, optic nerve imaging, IOP measurements documented
• Angle assessment: Gonioscopy performed confirming open angle, excluding angle-closure glaucoma
• Diagnosis code: ICD-10 code matching indication (H40.1x for open-angle, H40.00 for ocular hypertension, etc.)

Non-Covered Scenarios:

• Angle-closure glaucoma (contraindication)
• Acute angle closure (trabeculoplasty ineffective; needs iridotomy or other treatment)
• Inadequate medical trial documentation
• Prophylactic treatment for ocular hypertension without risk factors (payer-dependent)

5. National vs Local Coverage Determinations (NCDs/LCDs)

• No CMS National Coverage Determination (NCD) specifically for 65855
• Local Coverage Determinations (LCDs) vary by MAC:
  • Some MACs require minimum medical therapy trial (e.g., 3 months on 2+ agents)
  • Some allow SLT as primary therapy without medication failure
  • Documentation requirements vary slightly
• Always verify your MAC’s LCD before submitting

6. Separate Procedure Costs

• Gonioscopy (92020): Bundled into 65855, not separately billable
• Visual field testing (92083): Not included; can bill separately if distinct visit
• Optic nerve imaging (92004, 92201, etc.): Can bill separately if done as distinct service
• Medications: Topical anti-inflammatory or IOP-lowering drops are included in global package; not separately billable as supplies

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NATIONAL & LOCAL COVERAGE

National Coverage Status

Status: Covered by Medicare when medically necessary

CMS General Policy: Trabeculoplasty (laser-based) is covered for glaucoma management when criteria are met. No restrictive NCD currently applies.

Common Coverage Criteria by Payer

Payer Type	Coverage Status	Key Requirements
Medicare	Covered	Open-angle glaucoma, failed medical therapy or contraindication, baseline IOP/VF documented
BCBS (Major)	Covered	Often requires medical therapy trial (3-6 months); SLT increasingly covered as primary
United Healthcare	Covered	Similar to Medicare; check regional plan
Medicaid (State-Varying)	Usually Covered	Varies by state; some require prior authorization
Tricare	Covered	Standard glaucoma coverage applies
Indian Health Services (IHS)	Covered	Standard protocols apply

Common ICD-10 Codes Justifying 65855

ICD-10 Code	Description	Coverage Status
H40.101-H40.109	Primary open-angle glaucoma, right/left/bilateral	✓ Covered
H40.1091-H40.1099	Primary open-angle glaucoma with advanced/moderate/mild damage	✓ Covered
H40.20-H40.24	Pigmentary/pseudoexfoliative glaucoma	✓ Covered
H40.30-H40.33	Glaucoma secondary to eye trauma	✓ Covered
H40.40-H40.43	Glaucoma secondary to vascular disorder	✓ Covered (if meets medical necessity)
H40.00-H40.06	Ocular hypertension (not glaucoma), normal tension glaucoma	⚠️ Conditional (high-risk criteria)
H40.01-H40.06	Borderline/suspected glaucoma	⚠️ Check payer; often not covered without higher IOP or damage

Documentation Tip:

Use most specific ICD-10 code (including laterality and stage if known) to support medical necessity.

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2025 MEDICARE FEE SCHEDULE

Medicare 2025 Summary

Category	Value
Work RVU	3.00
PE RVU (Non-Facility)	4.04
Malpractice RVU	0.23
Total RVU (Non-Facility)	7.27
Conversion Factor (2025)	$32.35
National Average (Non-Facility, GPCI 1.0)	$235.16
Estimated Range (Non-Facility)	$220 - 250
National Average (Facility, GPCI 1.0)	~$196.99
Estimated Range (Facility)	$180 - 210

Geographic Cost Adjustments

The final payment varies by Geographic Practice Cost Index (GPCI):

Example: GPCI = 1.2 (high-cost area like urban CA)

• Non-Facility: $235.16 × (GPCI adjustment factor) = higher reimbursement

Example: GPCI = 0.8 (low-cost area like rural states)

• Non-Facility: $235.16 × (GPCI adjustment factor) = lower reimbursement

Check your locale’s GPCI on the CMS MPFS database.

Commercial & Other Payers (2025)

Payer Type	Estimated Range	Notes
Commercial (Average)	$800 - 2,500+	3-10× Medicare; highly variable by plan
Medicaid	$150 - 400	40-80% of Medicare; state-dependent
Self-Pay/Cash	$400 - 800	Office practices typically charge in this range

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AUDIT RED FLAGS & COMPLIANCE TIPS

Red Flags for Auditors

❌ No clear indication for trabeculoplasty

• Why was this procedure medically necessary?
• What is the baseline IOP and target IOP?

❌ Inadequate medical therapy documentation

• Auditors expect evidence of medication trials (names, duration, adverse effects)
• “Patient noncompliant” needs specific documentation, not just general statement

❌ Gonioscopy not documented

• Angle grade, pigmentation, angle-closure risk assessment MUST be documented
• No gonioscopy = procedure may not have been appropriately assessed

❌ No baseline visual fields or optic nerve imaging

• Glaucoma diagnosis should include baseline VF and/or disc imaging
• Missing baseline makes it harder to establish medical necessity

❌ Diagnosis code doesn’t match indication

• If chart says “open-angle glaucoma” but ICD-10 is “ocular hypertension,” mismatch triggers review

❌ Multiple trabeculoplasties billed incorrectly

• Billing two 65855 codes for 360° (180° + 180°) same session = duplicate; should be one 65855
• Repeat treatment within 10-day global must use -58 modifier

❌ Bilateral trabeculoplasty without justification

• Documentation must explain why BOTH eyes needed treatment same day

❌ Global period violation

• Billing post-op office visit without modifier within 10 days after 65855

❌ Medications or supplies billed separately

• Topical anti-inflammatory and IOP-lowering drops are part of global; cannot bill separately

Compliance Best Practices

✅ Always document clear medical necessity

• “Baseline IOP: Right 28 mmHg, Left 26 mmHg, on dorzolamide/timolol BID × 6 months without achieving target IOP of 18 mmHg. Visual fields stable. Patient tolerating medications without side effects but inadequate pressure control warrants laser trabeculoplasty.”

✅ Complete gonioscopy documentation

• “Gonioscopy (bilateral): Angle grade 3 bilaterally (open angles). Trabecular meshwork: Moderate pigmentation OU. No prior laser damage. No angle closure. Appropriate candidate for trabeculoplasty.”

✅ Specify laser parameters clearly

• “ALT applied: Argon laser, 50 μm spot, 0.1 second exposure, 600 mW power, 360° treatment with 75 total applications. Blanching endpoints achieved throughout treatment.”
• “SLT applied: Nd:YAG 1064 nm, 400 μm spot, energy 0.8 mJ, 360° coverage, microbubble endpoints achieved, 75 total applications.”

✅ Document pre-op IOP and post-op IOP

• “Pre-op IOP (applanation): Right 27, Left 25 mmHg. Immediate post-laser IOP (rebound tonometry): Right 29, Left 28 mmHg (expected transient elevation). Post-op drops instilled.”

✅ Include post-op inflammatory grading

• “Day 1 post-op: Anterior chamber: Trace reaction OU. Hyphema: None. IOP (applanation): Right 22, Left 21 mmHg. Responding well to topical prednisolone 1% QID.”

✅ Document laterality with modifiers

• Use -RT or -LT on claim to match chart documentation of which eye(s) treated

✅ If repeat treatment planned, document staging

• “Plan: Recheck IOP at 6 weeks. If inadequate reduction, repeat trabeculoplasty other eye (or contralateral eye’s remaining untreated quadrants) with -58 modifier (staged procedure).”

✅ Separate unrelated E/M with modifier -24

• If patient seen for unrelated eye problem during 10-day global period, code that E/M separately with -24 modifier

✅ Prior authorization when required

• Check payer requirements pre-procedure; obtain auth number and document

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FAQ - COMMON QUESTIONS

Q: What’s the difference between ALT and SLT?
A: Both use CPT 65855. ALT (argon laser) creates thermal burns, more scarring, less repeatable. SLT (selective laser, Nd:YAG) targets melanin-containing cells, less thermal damage, possibly repeatable. SLT increasingly used as first-line but both covered under same code.

Q: Can I bill 65855 + office visit (99212-99215) same day?
A: The office visit on the same day as the procedure decision is bundled into the global package (included). A post-op office visit within the 10-day global is also included. A separate, unrelated office visit during the global can be billed with -24 modifier if distinct reason documented.

Q: Is gonioscopy bundled into 65855?
A: Yes. Diagnostic gonioscopy (92020) is included in the global package for 65855. Do not bill separately.

Q: What if trabeculoplasty fails and I need to do trabeculectomy within 10 days?
A: Bill trabeculectomy (66170 or 66172) with -58 modifier (staged/more extensive procedure) on second claim. No reimbursement reduction with -58.

Q: Can I bill 65855 on both eyes same day?
A: Yes. Bill as:

• 65855-50 (bilateral) on single line with quantity 1, OR
• 65855-RT and 65855-LT on separate lines (verify payer preference) Medicare typically reimburses 150% of single-eye RVU for bilateral.

Q: What if I do 180° trabeculoplasty today and 180° another day - how do I code?
A: First treatment (180°): Bill 65855 (standard). Second treatment (180°, within 90-day global period): Bill 65855-58 (staged procedure). If >3 months apart: Bill two separate 65855 codes (new global period).

Q: Is retrograde pyelography part of 65855?
A: No. This is an ophthalmology code; “pyelography” is a urology term. If you’re treating glaucoma, trabeculoplasty is 65855. (Note: Different specialty entirely!)

Q: Can I bill 65855 if I only treated one quadrant due to patient request?
A: Yes, code 65855 even for partial treatment. Consider -52 modifier (reduced services) if significantly curtailed, but check payer policy - many don’t reduce for partial treatment. Document the reason for partial treatment.

Q: How long does effect of trabeculoplasty last?
A: Variable. Average 3-5 years; some patients 10+ years, some 1-2 years. Repeat treatment or escalation to other modalities may be needed.

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BILLING SCENARIOS & EXAMPLES

Scenario 1: SLT as First-Line Therapy (Office)

Patient: 54-year-old female with primary open-angle glaucoma, newly diagnosed (IOP 26 mmHg bilaterally, early field loss OU)

Clinical Decision:

• Baseline IOP 26 mmHg both eyes despite topical prostaglandin analog monotherapy × 3 weeks
• No ocular/systemic contraindications to glaucoma medications
• Patient educated: Can start 2 drops, but SLT is newer first-line option; chooses SLT trial first
• Documented medical justification: “SLT as primary therapy alternative to escalating topical therapy per AAO recent guidelines”

Procedure:

• SLT: 360° bilateral, both eyes same session
• Right eye: 1064 nm Nd:YAG, 75 applications, microbubble endpoints
• Left eye: 1064 nm Nd:YAG, 75 applications, microbubble endpoints
• Immediate post-op IOP: Right 28, Left 29 mmHg (expected spike)
• Topical prednisolone 1% QID and apraclonidine post-op

Coding:

• 65855-50 (bilateral SLT) OR 65855-RT + 65855-LT (payer-dependent)
• ICD-10: H40.1011 (primary open-angle glaucoma, right, mild damage); H40.1021 (left, mild damage)
• Medicare Payment (Non-Facility): ~$235.16\times 150$352.74 (if bilateral reimbursable) or split between two lines depending on payer

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Scenario 2: ALT Following Failed Medical Therapy (ASC)

Patient: 68-year-old male with ocular hypertension on timolol + brimonidine × 6 months, IOP still 24 mmHg both eyes, documented no side effects but inadequate control

Clinical Assessment:

• Prior to procedure: Gonioscopy confirmed open angles, moderate trabecular pigmentation, no angle closure
• Baseline visual fields: Normal (no field loss yet)
• Baseline optic nerve: Cup-disc 0.5 OU, no notching
• Target IOP: 16-18 mmHg
• Decision: Add third topical agent vs laser. Patient motivated for laser; ALT offered.

Procedure:

• ALT: Right eye 360°, left eye 360° (bilateral, same session)
• Argon laser: 50 μm spot, 0.1 sec exposure, 600 mW power
• Right eye: 80 applications, blanching endpoints
• Left eye: 80 applications, blanching endpoints
• Pre-op IOP: Right 24, Left 24 mmHg
• Post-op IOP: Right 26, Left 25 mmHg (transient spike)
• Prednisolone 1% 4× daily, apraclonidine same day

Coding:

• 65855-50 (bilateral ALT)
• ICD-10: H40.0031 (ocular hypertension, right eye); H40.0032 (ocular hypertension, left eye)
• Place of Service: 24 (ASC)
• Medicare Payment (Facility): ~$196.99\times 150$295.49 (if applicable)
• 6-Week Follow-Up: IOP measured: Right 18, Left 19 mmHg - successful ≥20% reduction ✓

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Scenario 3: SLT - Right Eye Only (Office)

Patient: 62-year-old male with advanced glaucoma, right eye worse than left (right IOP 30 mmHg on triple therapy, left IOP 20 mmHg on dual therapy); right eye showing progressive field loss

Clinical Decision:

• Right eye: Primary open-angle glaucoma, advanced, failing medical therapy on right alone
• Left eye: Primary open-angle glaucoma, mild, controlled adequately
• Decision: SLT right eye only; left eye continue observation

Procedure:

• SLT: Right eye only, 360° treatment
• 1064 nm Nd:YAG, 70 applications, microbubble endpoints
• Pre-op IOP: Right 30 mmHg
• Post-op IOP: Right 32 mmHg
• Inflammatory response: Mild anterior chamber reaction expected

Coding:

• 65855-RT (SLT right eye)
• ICD-10: H40.1111 (primary open-angle glaucoma, right eye, advanced damage)
• Medicare Payment (Non-Facility): ~$235.16
• Post-Op Day 1: IOP 24 mmHg (responding well)
• 4-Week Follow-Up: IOP 19 mmHg - significant improvement ✓

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Scenario 4: Repeat SLT (Left Eye, Second Treatment Same Eye)

Patient: 55-year-old female with bilateral primary open-angle glaucoma; underwent SLT both eyes 5 years ago (successful bilaterally), but now left eye IOP creeping up (21-23 mmHg despite ongoing drops); right eye stable (18 mmHg)

Clinical Decision:

• Left eye SLT effect waning after 5 years
• Options: Add/modify drops, repeat SLT, or progress to filtering surgery
• Patient prefers repeat SLT trial (minimally invasive, worked before)
• Global period of prior SLT expired (5 years ago)

Procedure:

• Repeat SLT: Left eye only, 360° treatment
• Similar laser parameters as before
• Pre-op IOP: Left 22 mmHg
• Post-op IOP: Left 25 mmHg

Coding:

• 65855-LT (repeat SLT, left eye)
• ICD-10: H40.1121 (primary open-angle glaucoma, left eye, moderate damage)
• Medicare Payment (Non-Facility): ~$235.16
• This is a NEW procedure (>90-day global from initial), so standard reimbursement applies (NOT -58 modifier)

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Scenario 5: SLT with Post-Op E/M During Global (Unrelated Condition)

Patient: 60-year-old male undergoing SLT today; also has mild dry eye syndrome and calls about eye irritation on post-op day 3

Coding Approach:

• 65855 (SLT) billed for surgical procedure (post-op day 3 is within 10-day global)
• 99212 (office visit E/M) with -24 modifier if visit is for unrelated condition (dry eye irritation, not post-op trabeculoplasty follow-up)
  • -24 modifier on E/M only, not on 65855
  • Different ICD-10 codes: K11.7x (dry eye) vs H40.1x (glaucoma)

Billing:

• 65855 (no modifier) - surgical code
• 99212-24 - office visit for unrelated dry eye issue
• Medicare: Both services may be billable given the distinct, unrelated nature

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REFERENCES & RESOURCES

• CMS Medicare Physician Fee Schedule (MPFS) 2025
• Medicare Medically Unlikely Edits (MUEs) - Current
• CPT® Professional Edition 2025 - American Medical Association
• ICD-10-CM Official Guidelines for Coding and Reporting
• American Academy of Ophthalmology (AAO) Glaucoma Guidelines
• Versant Health Clinical UM Guideline - Laser Trabeculoplasty (CG-SURG-100)
• Optometric Management - “Coding for Selective Laser Trabeculoplasty” (2024)
• American Optometric Association - SLT Scope of Practice by State

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Document Status: Complete & Ready for Obsidian Vault
Last Review: February 2026
Next Update Due: December 2026 (2027 Fee Schedule Release)
Specialty: Ophthalmology - Glaucoma Management
Keywords: Glaucoma, Laser Treatment, RVU, Medicare, Billing, Compliance