CPT® Code 00145

Quick Reference

• Code definition: CPT 00145 covers anesthesia services provided by a separate anesthesia provider (anesthesiologist or CRNA) for surgical procedures targeting the vitreous body and retina, performed in a hospital outpatient department or ambulatory surgical center.
• Payment formula: Anesthesia billing is not RVU-based. Payment equals (base units + time units + qualifying circumstance units) multiplied by the anesthesia conversion factor and local GPCI. CPT 00145 carries 7 ASA base units, the highest value in the ophthalmic anesthesia subrange [2][4].
• Time units: 1 unit per 15 minutes of documented anesthesia time. Anesthesia time runs from the start of continuous anesthesia provider presence (pre-induction preparation) through patient handoff to the post-anesthesia care unit. Billed time must reconcile exactly with the anesthesia record [2].
• Modifier essentials: A care modifier is required on every claim. Selection among AA, QK, QX, QY, QZ, and AD determines the payment rate. QS identifies monitored anesthesia care (MAC) and is informational for Medicare but required by many commercial payers.
• Documentation must-have: The anesthesia record must include start and end times, ASA physical status classification, provider identity and role, and explicit medical necessity justification for the anesthesia type when general or MAC anesthesia is used for a procedure where local anesthesia is a recognized alternative [2][3].
• Top confusion point: CPT 00145 applies only when a separate anesthesia provider bills independently. When the operating ophthalmologist personally administers a retrobulbar block, topical anesthesia, or personal sedation, no anesthesia code is separately billable; that service is included in the surgical global [2].
• Payer alert: No NCD or national LCD governs CPT 00145. Coverage is determined by the reasonable and necessary standard. The CY2026 Medicare anesthesia conversion factor is $33.4009 for non-QPP participants, up from $32.3465 in CY2025 [1].
• Age qualifying circumstance: CPT 99100 (extreme age, younger than 1 year or older than 70) is extremely common in the Medicare vitreoretinal population and adds 1 unit to the payment calculation. The threshold is strictly more than 70 years; a 70-year-old does not qualify.
• Emergency qualifying circumstance: CPT 99140 applies when surgical delay would substantially increase threat to vision or life. Acute macula-on retinal detachments and massive vitreous hemorrhage threatening central vision meet this threshold when properly documented.

When to Use This Code

CPT 00145 is the correct anesthesia code when an anesthesiologist or CRNA provides anesthesia services for any surgical procedure targeting the posterior segment of the eye, specifically the vitreous body and retina. Covered surgical procedures include pars plana vitrectomy (CPT 67036), vitrectomy with epiretinal membrane stripping, vitrectomy with endolaser panretinal photocoagulation, macular hole repair with ILM peel (CPT 67042), retinal detachment repair with vitrectomy (CPT 67108), and complex retinal detachment repair involving PVR or giant retinal tears (CPT 67113).

The code is appropriate in hospital outpatient departments (POS 22) and ambulatory surgical centers (POS 24). Inpatient cases (POS 21) for complex or urgent vitreoretinal surgery also use this code. Operative times range from approximately 45 minutes for straightforward vitrectomy to more than 3 hours for complex PVR repair, making formal anesthesia services appropriate across the full clinical spectrum.

CPT 00145 does NOT apply to:

• Office-based intravitreal injections (e.g., anti-VEGF agents such as aflibercept or ranibizumab). These are not surgical vitreoretinal procedures, and billing anesthesia services for them is a compliance risk directly flagged by the OIG ophthalmology work plan series [7].
• Anterior segment procedures. Cataract extraction (CPT 00142), corneal transplant (CPT 00144), and iridectomy (CPT 00147) each have distinct anesthesia codes within the same subcategory.
• Anesthesia administered by the operating surgeon. When the surgeon places a retrobulbar block or manages personal sedation without a separate anesthesia provider present, no anesthesia code is billable by the surgeon; the service is part of the surgical global [2].

Time calculation and worked example: One time unit equals 15 minutes of documented anesthesia time. Pre-operative evaluation and post-anesthesia recovery care on the day of surgery are bundled into the anesthesia fee and do not extend billable time.

Example: 74-year-old patient, vitrectomy for macular hole, MAC, anesthesia time 75 minutes.

• 7 base units + 5 time units (75 min divided by 15) + 1 qualifying circumstance (CPT 99100, patient is 74) = 13 total units × $33.4009 × local GPCI

Code Differentiation Table

The critical differentiator within the ophthalmic anesthesia subrange is the location of the surgical target. Procedures on the posterior segment (vitreous and retina) use 00145. When the same operative session includes both a vitreoretinal procedure and a cataract extraction, use only 00145; CPT prohibits reporting two anesthesia codes from the 00100 to 01999 range for the same operative session per patient [2].

Billing & Modifier Rules

Care Modifiers (Required on Every Claim)

The care modifier must reflect the actual service delivery arrangement for each case. Selecting the wrong modifier is both a billing error and a compliance risk [2][4]:

MAC Identification Modifiers

Modifier QS identifies monitored anesthesia care and may be stacked with the care modifier (e.g., AA and QS). It does not alter the Medicare payment calculation but is required by many commercial payers to confirm MAC delivery. Most vitreoretinal cases under 00145 are performed under MAC rather than general endotracheal anesthesia [2].

Modifiers G8 (MAC for a deep complex or markedly invasive surgical procedure) and G9 (MAC for a patient with severe cardiopulmonary condition) are supplemental MAC identifiers recognized by some payers. Review individual payer policy before appending either.

Unusual Anesthesia (Modifier 23)

Modifier 23 is appropriate when general anesthesia is used for a procedure that would normally be performed under local or regional anesthesia due to patient-specific circumstances. For vitreoretinal surgery, general anesthesia is often clinically appropriate given the complexity and duration of the procedure, so modifier 23 is most relevant for shorter, simpler posterior segment procedures where GA was required because of a specific patient condition (severe movement disorder, dementia, extreme claustrophobia). The anesthesia record must explicitly document why regional or local anesthesia was not appropriate [2].

Qualifying Circumstance Add-On Codes

Qualifying circumstance codes are add-ons reported in addition to 00145 and are never billed standalone. They carry Global status ZZZ (bundled) and must accompany the primary anesthesia code:

• CPT 99100: Extreme age (younger than 1 year or older than 70). Common in the Medicare vitreoretinal population. The threshold is strictly more than 70; age 70 does not qualify.
• CPT 99140: Emergency conditions. Apply when delay would substantially increase threat to the patient. Acute macula-on retinal detachments and massive vitreous hemorrhage threatening central vision meet this threshold when documented.
• CPT 99116: Total body hypothermia. Not applicable to routine vitreoretinal surgery.
• CPT 99135: Controlled hypotension. Not applicable to routine vitreoretinal surgery.

Add-On Code: 0887T

CPT 0887T (end-tidal control of inhaled anesthetic agents and oxygen to assist anesthesia care delivery) is a 2024 Category III add-on code reportable in conjunction with 00145 when applicable. It carries carrier-priced MPFS status; verify individual payer coverage before billing.

NCCI and Bundling

CPT 00145 and the surgeon's vitreoretinal procedure code (e.g., 67108) are submitted on separate claims by separate providers. No NCCI PTP edit pairs anesthesia codes with surgical procedure codes, and the anesthesiologist's claim is not subject to surgical global bundling rules [5].

Only one anesthesia code from the 00100 to 01999 range may be reported per operative session per patient. Billing 00145 alongside any other ophthalmic anesthesia code (00140, 00142, 00144, 00147, 00148) for the same session is prohibited [2].

CPT 00145 has no MUE. Anesthesia codes are time-based and are excluded from the CMS MUE program [2].

Documentation Essentials

The anesthesia record is the primary audit document. It must contain [2][3]:

• Patient identification, procedure date, surgical procedure name, and operating surgeon name
• Anesthesia start time (pre-induction) and end time (transfer to PACU)
• Continuous vital sign monitoring data (blood pressure, heart rate, oxygen saturation, end-tidal CO2)
• Anesthetic agents and doses administered
• ASA Physical Status classification (P1 through P6)
• Identity and role of each anesthesia provider (personally performing anesthesiologist, directing anesthesiologist, CRNA under direction, or independent CRNA)

Audit red flags specific to CPT 00145:

Anesthesia type justification absent. Medicare presumes ophthalmic procedures can be performed under topical or local anesthesia. The 2025 OIG anesthesia report identified $177 million in potentially improper payments attributable in part to absent or inadequate documentation of medical necessity for anesthesia when local alternatives exist [6]. The pre-anesthesia evaluation must record patient-specific factors justifying MAC or general anesthesia: examples include dementia or cognitive impairment preventing cooperation, severe anxiety or movement disorder, pediatric age, or anticipated procedure duration and complexity rendering local anesthesia clinically impractical.

Time unit discrepancy. Billed time units must reconcile exactly with the anesthesia record start and end times. Auditors calculate expected units from the documented times and compare against the claim. Any positive discrepancy constitutes an overpayment; systematic patterns trigger false claims scrutiny [2].

Care modifier inconsistency. The care modifier must match the actual service delivery arrangement documented in the anesthesia record and credentialing files. Billing AA when the anesthesiologist was directing concurrent cases (requiring QK) is an overpayment and a misrepresentation. Medical direction under QK requires documentation of all seven required elements: pre-anesthesia examination, prescribing the anesthesia plan, presence at induction and emergence, continuous availability, regular monitoring intervals, post-anesthesia evaluation, and no other simultaneous involvement incompatible with direction [4].

For hospital inpatient admissions, a post-anesthesia note is separately required in the medical record [3].

Medicare, Commercial & Medicaid Payer Rules

Medicare

CPT 00145 is payable as a professional Part B service when billed by an anesthesiologist or, in CRNA opt-out states, by a CRNA independently. No NCD or national LCD governs this code. Coverage is determined by the reasonable and necessary standard under §1862(a)(1)(A). Jurisdiction-specific MAC LCDs may apply; coders should consult the CMS Medicare Coverage Database for their MAC's anesthesia coverage policy.

CMS assigns no Work, PE, or MP RVUs to CPT 00145 (status J: Anesthesia Service). Payment is calculated exclusively via the base unit and time unit formula [1]:

• CY2026 conversion factor: $33.4009 (non-QPP participants); $33.57 (qualifying APM participants)
• CY2025 conversion factor: $32.3465 (3.3% year-over-year increase in CY2026)

APC status is "Packaged into APC Rates." On the facility OPPS claim, anesthesia cost is packaged into the surgical APC payment. The anesthesiologist's professional Part B claim is separate and does not interact with facility APC reimbursement.

Appropriate places of service are POS 21 (Inpatient Hospital), POS 22 (Outpatient Hospital), and POS 24 (ASC). Billing 00145 in POS 11 (office) for a surgical anesthesia case is a significant compliance concern and an audit trigger [2].

CRNA opt-out states: in states where the governor has exercised the Medicare physician supervision opt-out election, CRNAs may provide anesthesia without physician supervision and bill under QZ at the full conversion factor rate. Outside opt-out states, Part A hospital payment requires physician supervision, though the anesthesiologist's Part B billing is independent of this requirement [4].

Commercial Payers

Commercial payers generally follow the Medicare base unit and time unit framework but apply negotiated conversion factors that are not publicly listed. Key divergences to verify with individual payer contracts:

• Prior authorization requirements for MAC anesthesia in ASC settings or for cases anticipated to exceed a defined duration.
• QS modifier requirements vary; some commercial payers require QS on all MAC claims, others do not recognize it.
• G8 and G9 applicability varies by contract; review payer-specific policies before appending.
• CRNA supervision rules under commercial plans may differ from Medicare framework independent of state opt-out status.

Medicaid

State Medicaid programs vary substantially in anesthesia reimbursement methodology. Some use a unit-based formula similar to Medicare; others apply flat rates or require prior authorization for MAC anesthesia. Managed Medicaid plans may require preauthorization for elective vitreoretinal surgery anesthesia. Verify plan-specific requirements before billing.

Common Denials & Prevention

Insufficient documentation of medical necessity for anesthesia type

The most common audit finding for ophthalmic anesthesia cases. Occurs when the anesthesia type (MAC or general) is not justified in the pre-anesthesia evaluation relative to procedure complexity and patient-specific factors. The OIG's 2025 anesthesia report cited absent medical necessity documentation as a primary driver of improper payments in anesthesia for procedures where local alternatives exist [6].

Prevention: The pre-anesthesia evaluation must record patient-specific factors that preclude local or regional anesthesia. Acceptable examples include documented inability to cooperate due to cognitive impairment, anticipated procedure duration exceeding the threshold for patient cooperation under local technique, active movement disorder, or severe anxiety refractory to anxiolysis.

Time unit discrepancy between claim and anesthesia record

Billing time units that do not match documented start and end times. Auditors calculate expected units from the anesthesia record and compare against billed units. Systematic positive discrepancies generate recoupment demands and may trigger prepayment review [2].

Prevention: Extract start and end times directly from the anesthesia record for each claim. Apply partial unit rounding consistently per payer convention. Audit a random sample of claims quarterly for time unit reconciliation.

Incorrect care modifier selection

Billing AA when the anesthesiologist was medically directing concurrent CRNA cases (requiring QK) results in overpayment and misrepresentation. Using AD when the anesthesiologist was actually meeting all seven medical direction requirements (entitling QK) results in significant underpayment (3 base units versus 7) [4].

Prevention: Establish case-level attestation forms confirming the care arrangement. Train billing staff to distinguish between medical direction (2 to 4 concurrent cases, QK) and medical supervision (more than 4 concurrent cases, AD). Audit care modifier usage quarterly against anesthesia records and credentialing documentation.

Anesthesia billed for office-based intravitreal injection

Billing 00145 for an office-based intravitreal injection under sedation is a fraud risk. Intravitreal injections are not vitreoretinal surgery under the 00145 descriptor, and anesthesia billing for these injections is among the OIG's active ophthalmology work plan concerns [7].

Prevention: Confirm the procedure is a surgical vitreoretinal case performed in an ASC or HOPD before applying 00145. POS 11 with 00145 is a de facto audit trigger. Billing and coding staff should be trained on the distinction between surgical cases (CPT 67036 to 67113) and injection services (e.g., CPT 67028).

Qualifying circumstance applied to ineligible patient

Billing CPT 99100 for a patient aged 70 (not more than 70) or without age documentation in the record [2].

Prevention: Verify patient date of birth from the medical record before appending 99100. The criterion is strictly more than 70 years. Train billers on the exact age threshold; the margin of one year is a common underpayment or overpayment source in Medicare practices with high elderly patient volume.

Coding Scenarios

Scenario 1: Elective vitrectomy for macular hole, anesthesiologist personally performing MAC

A 74-year-old Medicare beneficiary undergoes elective pars plana vitrectomy with ILM peel and gas tamponade for a Stage 3 macular hole at an outpatient ASC. The anesthesiologist personally administers MAC. Anesthesia time is 75 minutes. No concurrent procedures are performed.

Correct coding: 00145 with AA and QS + 99100 / H35.31x (macular hole, appropriate laterality)

Why: AA confirms personal performance; QS confirms MAC delivery. 99100 applies because the patient is 74 (more than 70). Total units: 7 base + 5 time + 1 qualifying circumstance = 13 units. The surgeon independently bills CPT 67042 on a separate claim. The anesthesiologist's claim does not include the surgical CPT code.

Scenario 2: Emergency retinal detachment repair, macula-on, anesthesiologist directing 1 CRNA

A 68-year-old patient presents with an acute macula-on rhegmatogenous retinal detachment. Emergency vitrectomy (CPT 67108) is performed in the hospital OR. An anesthesiologist directs one CRNA under a medical direction arrangement. Anesthesia time is 120 minutes.

Correct coding: Anesthesiologist: 00145 with QY + 99140 / H33.001 to H33.009 (appropriate laterality). CRNA: 00145 with QX + 99140.

Why: QY and QX confirm the 1:1 medical direction arrangement; each provider bills at 50% of the conversion factor. 99140 applies because surgical delay would risk foveal involvement and permanent central vision loss; this must be explicitly stated in the documentation. The patient is 68 (not more than 70), so 99100 does not apply. Total units per provider at 50%: 7 base + 8 time + 2 qualifying circumstance (99140 = 2 units) = 17 units.

Scenario 3: Complex PVR repair, anesthesiologist directing 3 concurrent cases

A 77-year-old patient undergoes complex retinal detachment repair (CPT 67113) for stage C-2 proliferative vitreoretinopathy under general anesthesia. Anesthesia time is 210 minutes. The anesthesiologist is simultaneously directing CRNA cases in two other operating rooms.

Correct coding: Anesthesiologist: 00145 with QK + 99100 / H33.40 to H33.49 (appropriate laterality). CRNA: 00145 with QX + 99100.

Why: The anesthesiologist is directing 3 concurrent cases (within the QK threshold of 2 to 4). Billing AA would be a misrepresentation and would generate an overpayment. QK requires documentation of all seven medical direction elements. Total units at 50%: 7 base + 14 time (210 min divided by 15) + 1 qualifying circumstance (99100, patient is 77) = 22 units per provider at 50% each.

Scenario 4: Vitrectomy for diabetic vitreous hemorrhage, independent CRNA in opt-out state

A 71-year-old patient with type 2 diabetes undergoes vitrectomy (CPT 67036) for non-clearing vitreous hemorrhage from proliferative diabetic retinopathy. The ASC is in a CRNA Medicare opt-out state; no anesthesiologist is involved. Anesthesia time is 60 minutes.

Correct coding: 00145 with QZ + 99100 / H43.10 to H43.13 with E11.xx as applicable

Why: QZ applies when a CRNA provides anesthesia without physician direction or supervision in a state with the Medicare opt-out election. The patient is 71 (more than 70), so 99100 applies. Total units: 7 base + 4 time + 1 qualifying circumstance = 12 units at the full conversion factor rate.

Related Codes

• CPT 00140: Anesthesia for procedures on eye; NOS. Default ophthalmic anesthesia code when no specific subcategory fits; 5 base units.
• CPT 00142: Anesthesia for lens surgery. Cataract extraction and IOL procedures; 6 base units. Superseded by 00145 when combined anterior and posterior segment surgery is performed at the same session.
• CPT 00144: Anesthesia for corneal transplant. Penetrating and lamellar keratoplasty; anterior segment.
• CPT 99100: Qualifying circumstance; extreme age (younger than 1 year or older than 70). Extremely common add-on in Medicare vitreoretinal cases.
• CPT 99140: Qualifying circumstance; emergency conditions. Apply for acute, vision-threatening retinal emergencies with documented urgency.
• CPT 67036: Vitrectomy, mechanical, pars plana approach. The most common surgical procedure paired with 00145; billed by the operating ophthalmologist on a separate claim.
• CPT 67108: Repair of retinal detachment with vitrectomy. Most common retinal detachment repair code in the Medicare population; global 090.
• CPT 67113: Repair of complex retinal detachment (PVR, diabetic traction, giant tear) with vitrectomy and membrane peeling. Highest-complexity vitreoretinal surgical code; global 090.
• CPT 0887T: End-tidal control of inhaled anesthetic agents. Category III add-on reportable with 00145 when provided; carrier-priced; verify payer coverage.

Sources

1. CY2026 Medicare Physician Fee Schedule Final Rule (CMS-1832-F) Fact Sheet — CMS, October 2025 — CY2026 anesthesia conversion factor of $33.4009 (non-QPP), effective January 1, 2026.
2. CMS Claims Processing Manual, Chapter 12 (Physicians/Nonphysician Practitioners) — CMS — Anesthesia billing rules including time units, qualifying circumstances, care modifiers, medical direction requirements, and bundling policy (§40).
3. CMS Medicare Benefit Policy Manual, Chapter 15 (Covered Medical and Other Health Services) — CMS — Coverage of anesthesia services and MAC anesthesia policy.
4. 42 CFR §414.46 — Anesthesia Services — HHS/eCFR — Governing regulation for Medicare anesthesia payment formula, medical direction requirements, and CRNA payment rules.
5. CMS NCCI Policy Manual for Medicare Services — CMS — Anesthesia bundling rules; confirms no PTP edit pairing anesthesia codes with surgical procedure codes; one anesthesia code per session policy.
6. OIG: Medicare Could Have Saved an Estimated $177 Million — Anesthesia During Spinal Pain Management Procedures — HHS OIG, 2025 — Documents OIG scrutiny of anesthesia billed for procedures where local anesthesia is normally adequate; compliance standard applicable to ophthalmic anesthesia.
7. OIG Work Plan Series W-00-24-30100 — Intravitreal Injections — HHS OIG, 2024 — Ophthalmology compliance focus; flags risk of billing anesthesia for office-based vitreoretinal injections versus surgical procedures.