CPT® Code 00142

Quick Reference

• Code definition: CPT 00142 captures the anesthesia provider's professional service for any surgical procedure on the crystalline lens, including cataract extraction (phacoemulsification, extracapsular, intracapsular), intraocular lens (IOL) insertion or exchange, and removal of lens material by any technique.
• Key billing rule: Payment is time based using the formula: (Base Units + Time Units + Qualifying Circumstance Units) × Anesthesia Conversion Factor. CMS applies 1 time unit per 15 minutes [3]; commercial contracts frequently use 10-minute or 12-minute intervals. Always verify the payer contract before calculating units.
• Modifier essentials: Medicare requires one provider-type modifier on every 00142 claim: AA (anesthesiologist personally performed), QK (medical direction of 2 to 4 CRNAs), QY (medical direction of one CRNA), QX (CRNA under direction), or QZ (CRNA without supervision). Append QS for monitored anesthesia care (MAC).
• Documentation must-have: Anesthesia start and stop times are required on every claim. Missing times are the single most common denial trigger for 00142 and cannot be reconstructed retroactively [3].
• Top confusion point: Do not bill 00142 when the ophthalmologist administers only topical anesthetic drops and no anesthesiologist or CRNA is present. Billing 00142 in a topical-only case constitutes a false claim and is a named OIG compliance risk [6].
• Payer alert: In the hospital outpatient setting, APC Status Indicator = Packaged, meaning the facility receives no separate payment for anesthesia services [1]. The anesthesia provider's professional claim is still adjudicated separately under the Physician Fee Schedule using the anesthesia conversion factor formula.
• Age qualifier: Report qualifying circumstance code 99100 when the patient is under 1 year or over 70 years old. Because cataract surgery predominantly affects Medicare beneficiaries over 70, 99100 is routinely applicable and frequently omitted, resulting in systematic revenue loss.

When to Use This Code

CPT 00142 applies when a qualified anesthesia provider (anesthesiologist or CRNA) is present and providing anesthesia services during any surgical procedure involving the crystalline lens. Covered procedures include phacoemulsification with IOL implantation, complex cataract extraction, intracapsular cataract extraction, secondary IOL insertion, IOL exchange, and removal of lens material by aspiration, phacofragmentation, or pars plana approach.

The code captures all anesthesia delivery types: MAC with IV sedation, regional nerve block (retrobulbar or peribulbar), and general anesthesia. The anesthesia type does not change the code; it affects documentation requirements and applicable ancillary modifiers.

Scope boundary: Topical-only anesthesia cases fall outside the scope of 00142. When the operating surgeon administers topical anesthetic drops and no anesthesia provider participates in the case, no 00142 claim is supportable. The defining threshold is the presence of a qualified anesthesia provider who assumes patient responsibility, monitors physiologic parameters, and stands ready to convert to deeper sedation or general anesthesia if needed.

Provider and setting: CPT 00142 is the anesthesia provider's code. The operating surgeon bills the applicable surgical CPT (e.g., 66984 for routine phacoemulsification). These are separate providers submitting separate claims; the surgical and anesthesia codes are not bundled against each other. The Global Days indicator for 00142 is XXX, confirming the global concept does not apply to anesthesia services [1].

Code Differentiation Table

The most consequential differentiation is 00142 vs 00145. When cataract surgery and pars plana vitrectomy occur in the same operative session, use the anesthesia code with the higher base unit value from the current ASA Relative Value Guide [5]. Do not bill two anesthesia codes for a single continuous anesthesia service.

Never use 00140 for lens surgery. CPT 00140 is the "not otherwise specified" code for eye procedures; lens surgery has a dedicated specific code and defaulting to 00140 constitutes a coding inaccuracy that auditors flag on review.

Billing and Modifier Rules

Payment formula: Anesthesia services are not reimbursed under standard RVU methodology. CMS calculates payment as [3]:

(Base Units + Time Units + Qualifying Circumstance Units) × Anesthesia Conversion Factor

Anesthesia time begins when the provider assumes responsibility for the patient and ends when care is transferred post-procedure. Time between cases does not count. Verify the current year conversion factor from the CMS Physician Fee Schedule Final Rule each January [4].

Provider-type modifiers (required by Medicare):

One provider-type modifier is required on every anesthesia claim. A claim missing this modifier will deny or return as unprocessable.

MAC-specific modifiers: Append QS to identify monitored anesthesia care. For MAC in a patient with a history of severe cardiopulmonary conditions, G9 applies. G8 (MAC for deep complex or markedly invasive surgical procedures) does not typically apply to routine lens surgery under MAC.

Physical status modifiers (P1 through P5): The CPT codebook requires a physical status modifier on every anesthesia claim. Medicare does not recognize these modifiers for additional payment. Some commercial payers assign extra base units for P3 and P4 per ASA Relative Value Guide conventions [5]. Verify each payer contract individually.

Qualifying circumstance codes (list separately alongside 00142):

• 99100: Patient age under 1 year or over 70. Adds 1 base unit. MUE = 1; report once per session regardless of multiple qualifying conditions.
• 99140: Emergency conditions (e.g., traumatic lens dislocation requiring urgent surgery). Adds 2 base units.
• 99116 (total body hypothermia) and 99135 (controlled hypotension): Rarely applicable for lens surgery.

Add-on code: 0887T, end-tidal control of inhaled anesthetic agents, may be listed separately alongside 00142 when used (introduced in 2024). Verify current payer coverage before billing.

No MUE applies: Anesthesia codes are time based and do not carry a traditional Medically Unlikely Edit. Billing 00142 with multiple units of service for a single continuous anesthesia session is incorrect; additional time is captured through time units, not by repeating the procedure code.

Documentation Essentials

Required elements for every 00142 claim:

• Anesthesia start and stop times: The single most audited element. Document when the anesthesia provider assumes patient responsibility and when care is transferred. Times inconsistent with the surgeon's operative record are a primary audit finding.
• Type of anesthesia: MAC, retrobulbar or peribulbar block, or general anesthesia. Specifying type supports the QS modifier and establishes medical necessity for provider presence.
• Physical status: P1 through P6 with clinical justification in the pre-anesthesia evaluation. P3 and above require documentation of the specific systemic condition.
• Pre-anesthesia evaluation: A documented pre-operative assessment including medical history review, medication list, and the formulated anesthesia plan.
• Post-anesthesia note: Required in the medical record; necessary to demonstrate that post-anesthesia care was provided, which is also a TEFRA medical direction requirement [3].
• Medical necessity for provider presence: For MAC claims, the record must establish a clinical reason the patient required an anesthesia provider. Acceptable documentation includes complex medical comorbidities, patient inability to cooperate, or documented risk factors requiring readiness to convert to general anesthesia.

Audit red flags specific to 00142: OIG has identified MAC billing for cataract surgery as a compliance risk area [6]. Auditors cross-reference the anesthesia claim against operative and nursing records and flag: claims where only topical drops appear in the operative or nursing record with no IV access or sedation agents documented; absence of anesthesia start or stop times; QS modifier with no documentation of IV sedation agents or continuous monitoring entries; and anesthesia time inconsistent with surgical time on the surgeon's claim.

TEFRA medical direction requirements [3]: When billing QK, QY, or the paired QX claim, the anesthesiologist's record must document: pre-anesthesia examination and plan formulation, participation in the most demanding elements of the case, monitoring of the patient, immediate availability to respond, and provision of post-anesthesia care. Missing any element can reduce the claim from the medically directed rate.

Medicare, Commercial and Medicaid Payer Rules

Medicare:

CMS covers anesthesia for lens surgery when an anesthesia provider is present and medical necessity is documented [3]. There is no National Coverage Determination for cataract surgery anesthesia. Multiple Medicare Administrative Contractors have issued Local Coverage Determinations addressing MAC billing for cataract procedures, generally requiring documentation that the patient's medical condition necessitated an anesthesia provider rather than topical anesthesia alone. Verify the applicable MAC LCD before billing MAC for routine uncomplicated phacoemulsification.

The APC Status Indicator for 00142 is Packaged in the hospital outpatient setting, meaning the facility does not receive a separate payment line for anesthesia [1]. The anesthesia provider's professional claim is still adjudicated separately under the Physician Fee Schedule. In ambulatory surgery centers, verify current ASC fee schedule status, as ASC anesthesia payment has historically differed from hospital outpatient payment.

Medicare does not increase payment for physical status modifiers. The modifier is required on the claim for documentation purposes only and does not affect the allowed amount.

Commercial Payers:

Commercial contracts frequently specify time intervals different from CMS; 10-minute or 12-minute time units are common. Apply the contracted interval when calculating units and confirm this before billing. Some commercial payers recognize P3 and P4 physical status for additional base units per ASA Relative Value Guide conventions [5]; verify each contract. Prior authorization requirements for elective cataract anesthesia vary by plan; confirm requirements before the case when the payer policy mandates authorization.

Medicaid:

Coverage varies significantly by state and managed care plan. Some Medicaid plans impose prior authorization or restrict anesthesia coverage for elective cataract surgery to patients meeting specific documented criteria. Verify state policy and any managed Medicaid plan contracts before billing.

Common Denials and Prevention

Missing anesthesia start or stop times Anesthesia payment is time based; without both times, the claim cannot be adjudicated [3]. Retroactive reconstruction of times is not acceptable and creates additional audit exposure. Prevention: build start and stop time fields as mandatory entries in the anesthesia record template before any claim submission.

Topical anesthesia only, no provider present A claim for 00142 is not supported when the anesthesia record shows only topical drops administered by the surgeon with no anesthesiologist or CRNA involvement. Auditors cross-reference operative and nursing documentation [6]. Prevention: establish a pre-billing verification step confirming that an anesthesia provider was actively present and documented in the record before submitting 00142.

Missing or incorrect provider-type modifier Medicare requires AA, QK, QY, QX, or QZ on every anesthesia claim. A mismatch between actual provider roles and billed modifiers triggers compliance review. Prevention: configure claim-level billing edits that reject 00142 claims missing a required provider-type modifier before the claim reaches the payer.

Omission of 99100 for patients over 70 This add-on applies to the majority of cataract surgery patients and is frequently overlooked. Each omission represents systematic revenue loss across a high-volume code. Prevention: build an automated flag on all 00142 claims for patients over 70 that requires 99100 to be confirmed present or actively removed before claim submission.

00140 billed instead of 00142 Using the nonspecific eye anesthesia code for lens surgery creates a coding inaccuracy that surfaces during audit. Prevention: in the billing system, map lens surgery surgical codes (66982, 66984, 66985, and related) to trigger a 00142 prompt on paired anesthesia claims.

Coding Scenarios

Scenario: A 74-year-old patient with age-related nuclear cataract, right eye, undergoes routine phacoemulsification with IOL implantation at an ambulatory surgery center. The anesthesiologist personally administers MAC with IV propofol and midazolam and monitors the patient continuously throughout the procedure.

Correct coding: 00142-AA-QS-P2 + 99100 with diagnosis H25.11 (age-related nuclear cataract, right eye).

Why: AA confirms the anesthesiologist personally performed all aspects of anesthesia at 100% of the allowed fee. QS identifies MAC. P2 reflects mild systemic disease. 99100 is required because the patient is over 70 and adds one base unit to the payment calculation.

Scenario: A 79-year-old patient with posterior subcapsular cataract, left eye, and severe COPD undergoes complex cataract extraction (66982). A CRNA administers MAC under the medical direction of an anesthesiologist who is concurrently directing one other CRNA in an adjacent room.

Correct coding: Anesthesiologist bills 00142-QK-QS-P3 + 99100. CRNA bills 00142-QX-QS-P3 + 99100. Diagnosis: H25.042 (posterior subcapsular polar age-related cataract, left eye) with the applicable COPD code.

Why: QK on the anesthesiologist's claim and QX on the CRNA's claim reflect concurrent medical direction of 2 to 4 CRNAs; each provider bills at 50% of the standard fee. 99100 applies because the patient is over 70.

Scenario: A 5-year-old with unspecified infantile cataract, right eye, requires cataract extraction under general endotracheal anesthesia because the child cannot cooperate with a regional block. The anesthesiologist personally manages the airway throughout.

Correct coding: 00142-AA-P1 with diagnosis H26.001 (unspecified infantile and juvenile cataract, right eye). Do not report 99100.

Why: CPT 99100 applies only to patients under 1 year or over 70 years old; a 5-year-old does not qualify. General anesthesia is appropriate for a pediatric patient who cannot cooperate but does not change the anesthesia code. P1 reflects a healthy child with no systemic comorbidities.

Scenario: A 68-year-old patient with aphakia requires secondary IOL insertion (66985) at a rural critical access hospital. No anesthesiologist is on staff; a CRNA independently administers MAC without physician supervision.

Correct coding: 00142-QZ-QS-P2 with the aphakia diagnosis (H27.01 right eye, H27.02 left eye, or H27.03 bilateral, per laterality in the operative report).

Why: QZ identifies CRNA service without medical direction by a physician. The patient is 68 years old; 99100 does not apply because the threshold is age over 70. If this patient were 71, 99100 would be required.

Related Codes

• 00140: Anesthesia for eye; not otherwise specified. Use only when no more specific eye anesthesia code applies.
• 00144: Anesthesia for eye; corneal transplant. Use for penetrating or lamellar keratoplasty.
• 00145: Anesthesia for eye; vitreoretinal surgery. Use for posterior segment procedures including pars plana vitrectomy.
• 99100: Anesthesia qualifying circumstance, extreme age. List separately alongside 00142 when the patient is under 1 year or over 70.
• 99140: Anesthesia qualifying circumstance, emergency conditions. List separately for urgent or emergent lens surgery (e.g., traumatic lens dislocation).
• 66984: Extracapsular cataract removal with IOL, routine phacoemulsification. The surgical code most commonly paired with 00142; billed by the surgeon, not the anesthesia provider.
• 66982: Complex extracapsular cataract removal with IOL. Paired when the case involves small pupil, subluxated lens, pseudoexfoliation, or pediatric presentation.
• 0887T: End-tidal control of inhaled anesthetic agents. Add-on to 00142 when this technology is used (introduced 2024; verify payer coverage).

Sources

1. CPT Code Set Database, Coding Ahead internal (accessed 2026-03-18): Code descriptors, status indicators, global days, APC status, type of service, modifier usage data, and code history for 00142 and related codes.
2. ICD-10-CM Code Set Database, Coding Ahead internal (accessed 2026-03-18): Code descriptors for H25.x cataract codes, H26.x infantile and juvenile cataract codes, and H27.x aphakia codes.
3. CMS Medicare Claims Processing Manual, Chapter 12: Anesthesia billing rules, time documentation requirements, provider-type modifier requirements, and TEFRA medical direction standards.
4. CMS Physician Fee Schedule: Annual anesthesia conversion factor; verify the current year value each January following the Final Rule publication.
5. ASA Relative Value Guide (RVG): Base unit values for 00142 and qualifying circumstance codes; physical status unit conventions for commercial payers.
6. HHS OIG Work Plan: MAC services for cataract surgery identified as a billing compliance risk area; OIG findings on claims where only topical anesthesia was administered with no anesthesia provider involvement.
7. CMS NCCI Policy Manual: Anesthesia unbundling rules, PTP edit guidance, and services included in the anesthesia package.