Cataract surgery is one of the highest-volume procedures in Medicare. When the anesthesia line on a cataract claim is denied, the cause is rarely clinical. It is usually base units, modifiers, or missing medical necessity documentation.
CPT code 00142 reports anesthesia for lens surgery. The descriptor is short, the case is fast, and the payment formula depends on three variables most billing teams get partly wrong: the base unit value loaded for each payer, which care team modifier fits the supervision arrangement, and whether monitored anesthesia care was justified in writing before the patient entered the room.
This guide covers the CPT 00142 billing guidelines that decide whether the claim pays: base units, modifiers, documentation, and the denials that follow when any of them slip. It assumes the broader rules of anesthesia medical billing are already in place.
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What Is CPT Code 00142?
CPT code 00142 is the anesthesia CPT code for cataract surgery and other lens procedures. It sits in the 00100–01999 anesthesia section of the CPT code set, inside the eye family at 00140–00148.
The anesthesiologist, CRNA, or anesthesiologist assistant reports 00142 on the CMS-1500. The ophthalmologist bills the surgical code separately. Reviewing the wider set of anesthesia CPT codes before assignment prevents most crosswalk errors.
CPT Code 00142 Description
The AMA CPT descriptor reads anesthesia for procedures on the eye; lens surgery. In practice, anesthesia for lens surgery under this code covers:
- Cataract extraction
- Phacoemulsification
- Intraocular lens (IOL) insertion
- Refractive lens exchange
It applies whether the anesthetic is topical with sedation, regional block, monitored anesthesia care, or general.
Clinical Applications of CPT Code 00142
Routine Phacoemulsification With IOL
A 74-year-old with age-related nuclear cataract, right eye, presents to an ambulatory surgery center. The surgeon performs phacoemulsification with IOL insertion and bills 66984. The CRNA provides sedation and monitoring, documents 19 minutes of anesthesia time, and reports 00142.
Complex Cataract
Zonular weakness and a dense lens push the surgeon to 66982 rather than 66984. The anesthesia code does not change. CPT 00142 still applies, but case length rises, so time units rise with it.
Intracapsular Extraction With IOL
Less common, billed by the surgeon under 66983. Anesthesia remains 00142.
Refractive Lens Exchange
A clear-lens exchange for refractive purposes still meets the descriptor. The coding is identical; the coverage question is not. Many payers treat the procedure as non-covered, which takes the anesthesia line with it.
When Not to Use CPT Code 00142
YAG laser capsulotomy for secondary membrane, billed by the surgeon under 66821, is not lens surgery in the anesthetic sense and rarely supports a separate anesthesia claim at all.
Vitreoretinal and corneal cases belong to their own codes. Submitting 00142 for either is incorrect code selection, and a payer that spots it will treat the error as a pattern rather than a one-off.
CPT Code 00142 vs. Related Eye Anesthesia Codes
| Code | Descriptor | Medicare Base Units |
|---|---|---|
| 00140 | Eye; not otherwise specified | 5 |
| 00142 | Eye; lens surgery | 4 |
| 00144 | Eye; corneal transplant | 6 |
| 00145 | Eye; vitreoretinal surgery | 6 |
| 00147 | Eye; iridectomy | 4 |
| 00148 | Eye; ophthalmoscopy | 4 |
ASA’s Relative Value Guide matches Medicare at 4 units for 00142. Confirm the other five against your current RVG edition before loading commercial fee schedules.
Practices billing across the full eye family benefit from specialty-aligned ophthalmology billing services rather than general coding support.
00142 Base Units and Reimbursement
Anesthesia base units represent baseline complexity, risk, and pre- and post-operative work for a code, independent of case length. You look them up; you never calculate them.
The 00142 base units are 4 for every payer class. The CMS Anesthesia Base Units file assigns 4, and ASA lowered its Relative Value Guide value from 6 to 4 in 2009 after surveying its own members, who valued the code at 4 at both the median and the 25th percentile. Many coding sites still publish 6. Billing 6 units to a commercial payer creates an overcharge that the payer can reduce or recoup.
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CPT 00142 payment formula · CMS 2026 anesthesia conversion factor
Time units are not whole numbers under Medicare. The MAC divides reported anesthesia time by 15 and rounds to one decimal place, so a 22-minute case yields 1.5 time units rather than 1. Report actual anesthesia time in minutes, and exclude any interval during which the practitioner was not furnishing continuous anesthesia care.
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Worked 22-minute cataract case · illustrative commercial contract rate
CMS finalized two anesthesia conversion factors for 2026: $20.4976 for most clinicians and $20.5998 for qualifying APM participants. Both are national figures before geographic adjustment. Your MAC publishes the locality file that actually prices 00142 reimbursement where you practice.
CPT 00142 Modifiers
Every claim needs one care team modifier establishing who delivered the anesthetic.
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Care team modifier selection · CPT 00142
Medical direction requires all seven steps in 42 CFR 415.110: the pre-anesthetic exam and evaluation, prescribing the plan, personal participation in the most demanding parts including induction and emergence where applicable, delegating the rest only to a qualified provider, monitoring at frequent intervals, remaining physically present and available for emergencies, and providing post-anesthesia care. Miss one and QY or QK collapses to AD, which pays on three base units plus a time unit when presence at induction is documented. Whether a CRNA billing QZ needs physician supervision for Medicare depends on your state’s opt-out status, a separate question from medical direction.
Technique and status modifiers:
| Modifier | Use |
|---|---|
| QS | Monitored anesthesia care. Informational; append whenever MAC is billed |
| G8 | MAC for deep, complex, or markedly invasive procedures. Novitas restricts G8 to six anesthesia codes, and 00142 is not among them |
| G9 | MAC for a patient with a history of severe cardiopulmonary disease |
| P1 to P6 | ASA physical status. P3 adds one unit and P4 two under ASA rules; Medicare does not recognize physical status for payment |
| 23 | Unusual anesthesia |
Qualifying circumstance add-on codes. 99100 (extreme age) and 99140 (emergency conditions) are add-on CPT codes, not modifiers. Medicare does not recognize qualifying circumstances for additional payment, though ASA’s payer survey put commercial coverage near 85 percent.
A retrobulbar block administered as the surgical anesthetic is included in 00142. Reporting it separately invites a bundling denial, not additional payment.
Monitored Anesthesia Care Documentation for Cataract Surgery
This is the single largest denial driver on the code. Cataract extraction is routinely performed under topical anesthesia with no anesthesia professional present, so monitored anesthesia care for cataract procedures is never automatically payable. Medical necessity is set by your Medicare Administrative Contractor’s LCD and billing article for anesthesia services, and the requirements vary by jurisdiction. Novitas article A57361 is the reference most often quoted, but 00142 does not appear on its supported code list, so do not assume it governs your claim.
Qualifying conditions include significant anxiety disorder, movement disorders, severe cardiac or pulmonary disease, developmental disability, and communication barriers. Under most MAC policies, patient preference alone does not qualify. Neither does surgeon preference.
A defensible file contains four things:
- The pre-anesthesia evaluation
- A medical necessity statement for MAC naming the qualifying condition
- The anesthesia record showing EKG, pulse oximetry, and blood pressure monitoring
- Documented start and stop times that reconcile with the time units billed
Diagnosis linkage matters just as much. H25.11 and H25.12 are not interchangeable, and the eye on the anesthesia claim must match the operative report. H25.13 covers bilateral disease; H25.9 and H26.9 are unspecified and weaken medical necessity wherever laterality could have been documented.
Common Denials on CPT Code 00142
- CARC B7: provider not certified or eligible for that date of service. Check enrollment, credentialing, and the rendering NPI.
- CO-4: procedure inconsistent with the modifier, or a required modifier missing, such as QX billed without the matching QK or QY claim.
- CO-16: claim lacks information, typically absent start and stop times.
- CO-97: bundling into the surgical payment, raised when the anesthesia line looks inseparable from the surgeon’s service.
- MAC without necessity: no qualifying diagnosis, no documented justification.
- Laterality mismatch: diagnosis eye does not match the operative eye.
Catching these denial codes before submission is the premise of denial management services.
Payer Considerations
Medicare. No separate payment for physical status modifiers or qualifying circumstance codes.
Commercial. Four base units under the current ASA Relative Value Guide, contracted conversion factor, and physical status and qualifying circumstances often payable. Verify per contract.
Facility setting. Most lens surgery happens in an ambulatory surgery center or hospital outpatient department. The anesthesia claim goes on the CMS-1500 in either setting. The facility claim differs: a hospital outpatient department bills on the UB-04, while a Medicare-certified ASC bills on the CMS-1500. Some commercial payers require the UB-04 from ASCs, so check the contract and align both claims through your ambulatory surgery center billing workflow so time documentation reconciles.
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Contact UsConclusion
Three variables decide whether a 00142 claim pays cleanly: the correct base unit value in every payer profile, the care team modifier matched to the documented supervision arrangement, and a MAC justification written before the procedure rather than reconstructed after a denial.
Audit every payer profile in your system for 4 base units on 00142, and the most expensive of those three stops being a judgment call. For the other two, consistent pre-submission review is what separates practices that appeal cataract anesthesia claims from practices that don’t. Our medical billing services team can audit your last 90 days of 00142 claims and show you which bucket you’re in.
