CPT code 00145 describes anesthesia services provided during vitreoretinal surgery — procedures involving the eye’s vitreous body and retina. According to the AMA CPT code set, the full descriptor reads: “Anesthesia for procedures on the eye; vitreoretinal surgery.” The American Society of Anesthesiologists (ASA) has assigned this code 6 base units, reflecting the specialized monitoring demands and positioning considerations that distinguish posterior segment eye surgery from less complex ophthalmic procedures. This code is reported by anesthesiologists, CRNAs, and anesthesiologist assistants — not by the operating surgeon.
What Does CPT Code 00145 Mean?
CPT 00145 is a standalone anesthesia procedure code covering the complete anesthetic episode for vitreoretinal surgical procedures. It falls within the 00100–01999 anesthesia code range and sits under the subcategory “Anesthesia for procedures on eye.”
Key attributes of this code:
- Billable status: Active; no AMA descriptor changes pending as of 2026
- Applicable setting: Hospital inpatient, hospital outpatient, and ambulatory surgery center (ASC)
- Provider type: Anesthesiologist (MD/DO), CRNA, or Anesthesiologist Assistant (AA) — always billed separately from the surgeon’s procedural claim
- Service category: Anesthesia — reported using base units + time units, not the standard RVU-based physician fee schedule formula
- Unilateral code: CPT 00145 is a unilateral service by default
What Procedures Does CPT 00145 Cover?
CPT 00145 applies when an anesthesia provider manages the anesthetic care for any vitreoretinal surgical intervention, regardless of the specific surgical CPT code the ophthalmologist uses. Vitreoretinal surgery broadly targets the posterior segment of the eye — the vitreous gel, retina, macula, and associated vasculature.
Clinical scenarios appropriately covered under this code include:
- Pars plana vitrectomy (PPV) for diabetic vitreous hemorrhage, retinal detachment repair, or epiretinal membrane removal
- Scleral buckle procedures for rhegmatogenous retinal detachment
- Membrane peeling for macular pucker or vitreomacular traction
- Pneumatic retinopexy with cryotherapy requiring full anesthetic management
- Endolaser photocoagulation performed under general or regional anesthesia
- Foreign body removal from the posterior segment
- Intravitreal injection procedures when performed in the OR under full anesthesia (less common but appropriate when the clinical situation demands it)
What Does CPT 00145 Specifically Exclude?
Not every ophthalmic anesthesia service falls under 00145. The following services require separate codes:
- Anterior segment procedures (lens extraction/cataract surgery) → CPT 00142
- Corneal transplant (penetrating keratoplasty or DSAEK) → CPT 00144
- Iridectomy (surgical or laser, when requiring full anesthesia) → CPT 00147
- Diagnostic ophthalmoscopy requiring anesthesia → CPT 00148
- MAC (monitored anesthesia care) only for in-office intravitreal injections billed without an OR setting — these are typically not separately billable under Medicare
When Is CPT 00145 the Right Code to Use?
Correct selection of CPT 00145 requires confirming four criteria before the claim is submitted:
- Confirm the surgical target is the posterior segment. If the operative report references the vitreous, retina, macula, or subretinal space, 00145 is appropriate. Procedures limited to the cornea, lens, or iris belong to adjacent codes.
- Confirm that a qualified anesthesia provider — not just the surgeon — managed the anesthetic. Surgeons administering their own local anesthesia are reported differently (modifier 47, rarely applicable here).
- Confirm the anesthesia type. General anesthesia is most common, but regional block (retrobulbar or peribulbar block with monitored sedation) also qualifies when the anesthesia provider manages the entire episode.
- Confirm the case is unilateral as documented in the operative report. If bilateral vitreoretinal procedures are performed under a single anesthetic administration — an uncommon but valid scenario — modifier 50 should be appended.
How Does CPT 00145 Differ From 00142, 00144, and 00147?
In practice, the most common misapplication involves confusing 00145 with 00142 (lens procedures), particularly when a combined cataract and vitrectomy case is performed. When multiple eye procedures are performed under a single anesthetic, only the highest base unit code is reported — the total anesthesia time covers all concurrent work.
| CPT Code | Procedure | ASA Base Units | Key Differentiator |
|---|---|---|---|
| 00142 | Lens surgery (cataract) | 6 | Anterior segment; crystalline lens |
| 00144 | Corneal transplant | 7 | Full-thickness or lamellar keratoplasty |
| 00145 | Vitreoretinal surgery | 6 | Posterior segment; vitreous/retina |
| 00147 | Iridectomy | 4 | Iris removal; lower complexity |
| 00148 | Ophthalmoscopy | 4 | Diagnostic; lowest complexity |
Note: When a combined cataract extraction + PPV is performed, select the single code with the highest base unit value. Because 00144 (corneal transplant, 7 units) ranks above both 00142 and 00145 (6 units each), the tiebreaker between those two in a combined case defaults to 00142 per ASA Crosswalk® guidance — verify with your payer.
What Documentation Is Required to Support CPT 00145?
Anesthesia documentation follows a different framework than surgical or E&M coding. The anesthesia record — whether paper or integrated within the EHR — serves as the primary source document for both compliance and claims adjudication.
What Must the Anesthesia Provider Document in the Clinical Record?
The anesthesia record must capture all of the following to support a compliant 00145 claim:
- Pre-anesthesia evaluation — ASA physical status assignment, relevant comorbidities, airway assessment, and medication reconciliation, completed before induction
- Anesthesia start time — the moment the provider begins preparing the patient for induction in the OR or procedure suite (not the time of surgical incision)
- Anesthesia end time (stop time) — documented as the moment the anesthesia provider’s personal attendance ends and the patient is transferred to post-anesthesia care (PACU or equivalent)
- Type of anesthesia — general endotracheal, LMA, regional block, or MAC, as applicable
- Medications administered — agents, dosages, routes, and times
- Monitoring modalities — ECG, pulse oximetry, capnography, arterial line if used
- Intraoperative events or complications — including any changes in patient status that justify a physical status upgrade or qualifying circumstance code
- Post-anesthesia care transfer note — confirming safe handoff
What Are the Time Documentation Standards for CPT 00145?
Accurate start and stop times are legally and financially critical. Key rules:
- Time is calculated from preparation for induction to safe transfer to PACU — not from surgical incision to closure
- CMS and most commercial payers require time in minutes (not hours), typically entered in Box 24G of the CMS-1500 form or the equivalent 5010 EDI segment
- One time unit = 15 minutes under Medicare; some commercial payers round to the nearest minute
- Missing stop time is a False Claims Act audit trigger — the CMS Medicare Claims Processing Manual, Chapter 12 explicitly addresses this requirement
- EHR-generated anesthesia records must sync with manually recorded start/stop times — discrepancies between systems are a common RAC review target
How Does CPT 00145 Affect Medical Billing and Reimbursement?
Anesthesia reimbursement does not follow the standard RVU-based physician fee schedule formula. Instead, payment is calculated using the anesthesia unit formula:
(Base Units + Time Units + Physical Status Units* + Qualifying Circumstance Units*) × Conversion Factor = Allowed Amount
*Medicare does not reimburse physical status or qualifying circumstance units; many commercial payers do — verify by contract.
| Component | CPT 00145 Value | Notes |
|---|---|---|
| Base Units (ASA/CMS) | 6 | Fixed for all 00145 claims |
| Time Units | Variable | 1 unit per 15 min of anesthesia time |
| Physical Status Units (P3–P5) | +1 to +3 units | Commercial payers only; Medicare excluded |
| Qualifying Circumstance Units | +0 to +5 units | Based on 99100, 99116, 99135, 99140 |
| 2026 CMS Anesthesia Conversion Factor | $20.4976/unit | Per CY 2026 Physician Fee Schedule Final Rule |
Illustrative example: A 75-year-old diabetic patient (P3 classification) undergoes a 90-minute vitrectomy. Billing under Medicare: (6 base + 6 time) × $20.4976 = $147.58. Under a commercial payer recognizing P3 (+1 unit): (6 + 6 + 1) × commercial CF = higher reimbursement.
Billing teams at multi-specialty practices routinely undervalue these claims by failing to capture complete time or overlooking the physical status classification on the pre-op evaluation note.
What Modifiers Are Commonly Used With CPT 00145?
Anesthesia payment modifiers must be appended in the first modifier position. Claims submitted without these modifiers will be denied as a billing error by most payers.
| Modifier | Description | When to Apply | Reimbursement Impact |
|---|---|---|---|
| AA | Anesthesiologist personally performed | MD/DO provides full case | 100% of allowed amount |
| QK | MD medical direction of 2–4 concurrent CRNAs | Anesthesiologist directing multiple simultaneous rooms | 50% of allowed amount |
| QY | MD medical direction of one CRNA | Single concurrent direction | 50% of allowed amount |
| QX | CRNA with MD medical direction | CRNA bills concurrent case | 50% of allowed amount |
| QZ | CRNA without MD direction | Independent CRNA in opt-out states | 100% of CRNA fee schedule |
| AD | MD supervising >4 concurrent procedures | Exceeds medical direction threshold | 3 base units only; no time |
| P1–P6 | Physical status | All cases; reflects patient health status | Additive units (commercial only) |
| 23 | Unusual anesthesia | General anesthesia for procedure normally under MAC/local | No additional payment; explains clinical necessity |
| 50 | Bilateral procedure | Bilateral simultaneous vitreoretinal surgery | Rate adjustment per payer policy |
| 99100 | Qualifying circumstance: extreme age | Patient under 1 year or over 70 | Additive units (commercial payers) |
Are There Prior Authorization, Coverage Restrictions, or LCD Requirements?
- Medicare covers CPT 00145 when medically necessary anesthesia is provided during a covered vitreoretinal surgical procedure. No national coverage determination (NCD) restricts 00145 directly, but the underlying surgical procedure must meet medical necessity requirements under applicable Local Coverage Determinations (LCDs) for retinal surgery.
- Medicaid coverage varies by state. Some state Medicaid programs require prior authorization for non-emergency vitreoretinal procedures; confirm with the applicable state MAC or managed Medicaid plan.
- Commercial payers may require PA for elective vitreoretinal cases. Anesthesia authorization is typically bundled with the surgical authorization — confirm this with pre-cert teams before the date of service.
- ASC setting: CMS bundles anesthesia payments for Medicare patients receiving services in ASCs under the Outpatient Prospective Payment System (OPPS); the facility fee typically covers anesthesia costs when surgery is performed in an ASC under Medicare.
What CPT or HCPCS Codes Are Commonly Billed Alongside CPT 00145?
The following codes frequently appear on the same date of service as 00145. Understanding pairing context and bundling risk is essential for clean claims.
| Associated Code | Description | Typical Pairing Context | Bundling Risk |
|---|---|---|---|
| 67108 | Repair of retinal detachment, vitrectomy | Primary surgical procedure driving 00145 | No — separate claims |
| 67113 | Complex retinal detachment repair | High-complexity vitreoretinal case | No — separate claims |
| 67040 | Endolaser panretinal photocoagulation | Add-on to vitrectomy | Review NCCI edits |
| 99100 | Qualifying circumstance: extreme age | Patient ≥70 or <1 year | No — additive to anesthesia claim |
| 99135 | Qualifying circumstance: hypotensive/controlled anesthesia | When deliberate hypotension used | No — additive |
| 01999 | Unlisted anesthesia procedure | When procedure falls outside standard descriptors | Requires documentation |
| G8 / QS | MAC monitoring codes | When MAC is performed rather than general/regional | Modifier only; not billed as separate code |
Which Code Combinations Trigger NCCI or CCI Edits?
- CPT 00145 billed with the surgical CPT code on the same claim line will be denied — the anesthesia code is always billed on the anesthesiologist’s claim, not the surgeon’s claim. This is a common submission error in small practices.
- Billing 00145 and 00142 together for a combined cataract + vitrectomy case is incorrect — only the highest base unit code applies. Submit the single applicable code with the combined case time.
- Qualifying circumstance codes (99100, 99116, 99135, 99140) are add-ons, not standalone codes — they cannot be submitted without an accompanying anesthesia base code. Submitting them as primary codes triggers an NCCI edit.
- Review CMS NCCI Chapter 2 (Anesthesia Services) annually, as edits are updated quarterly.
What Coding Errors Should You Avoid With CPT 00145?
In practice, the following errors account for the majority of 00145 claim denials, audits, and compliance findings:
- Omitting the payment modifier — Claims submitted without AA, QK, QZ, or equivalent modifiers are denied outright by most payers. The modifier must appear in the first modifier position.
- Misidentifying the surgical target — Coding 00145 for an anterior segment procedure (e.g., cataract extraction alone) when 00142 is correct. Always crosswalk the operative CPT code against the anesthesia code before billing.
- Incorrect time documentation — Recording surgical incision-to-close time instead of anesthesia start-to-transfer time. These are rarely identical and the discrepancy is flagged during RAC reviews.
- Billing both 00145 and the surgical code on one claim — Anesthesia is always a separate claim from the surgeon’s claim.
- Failing to assign physical status — Even if Medicare doesn’t pay for P-modifiers, they must still be documented and appended for commercial claims. Omitting P-status results in underpayment on commercial contracts.
- Upcoding qualifying circumstances without documentation — Appending 99100 (extreme age) or 99135 (controlled hypotension) without the pre-op evaluation or anesthesia record to support it is an OIG-flagged risk pattern.
What Do Auditors and RAC Reviewers Look for When Reviewing CPT 00145 Claims?
- Mismatch between claimed anesthesia time and OR log time — RAC auditors routinely cross-reference the facility’s OR records against the anesthesiologist’s time claim
- Missing pre-anesthesia evaluation note — Required by CMS for all general anesthesia cases; its absence signals incomplete documentation
- Concurrent case billing without clear direction documentation — When QK or QY modifiers are used, the anesthesiologist must document all seven medical direction requirements outlined in the CMS Medicare Claims Processing Manual, Chapter 12, Section 50
- Physical status upgrades without clinical justification — Assigning P4 or P5 to a routine diabetic patient without documented systemic compromise is an audit red flag
How Does CPT 00145 Relate to Other Anesthesia CPT Codes?
| Related Code | Relationship Type | Key Distinction |
|---|---|---|
| 00142 | Peer code (same subcategory) | Anterior segment; lens surgery |
| 00144 | Peer code (same subcategory) | Corneal transplant; 1 more base unit |
| 00147 | Peer code (same subcategory) | Iridectomy; lower complexity (4 units) |
| 00148 | Peer code (same subcategory) | Diagnostic ophthalmoscopy; lowest complexity |
| 00140 | Parent-range code | General “procedures on eye” NOS; use only when no specific code applies |
| 99100 | Add-on/qualifying circumstance | Extreme age; appended to 00145, not standalone |
| 99135 | Add-on/qualifying circumstance | Controlled hypotension; appended to 00145 |
| 01999 | Unlisted anesthesia | When procedure is not covered by existing anesthesia descriptor |
What Is the Correct Code Sequencing When CPT 00145 Appears With Other Codes?
- Report CPT 00145 as the primary anesthesia code on the anesthesia claim.
- Append the appropriate provider payment modifier in the first modifier position (AA, QK, QY, QX, QZ, or AD).
- Append the appropriate physical status modifier (P1–P5) in the second modifier position.
- If applicable, append qualifying circumstance codes (99100, 99116, 99135, or 99140) as separate line items on the same claim — these are CPT add-on codes, not modifiers.
- Report ICD-10-CM diagnosis codes that establish medical necessity for both the vitreoretinal procedure and the anesthesia service (e.g., H33.001 for unspecified retinal detachment with retinal break, right eye).
- If multiple anesthesia procedures occur on the same date under a single anesthetic, report only the code with the highest base unit value — report total continuous time across all procedures.
Real-World Coding Scenario — How CPT 00145 Is Applied in Practice
Patient encounter: A 68-year-old patient with proliferative diabetic retinopathy and non-clearing vitreous hemorrhage presents to an ophthalmology ASC for planned pars plana vitrectomy (PPV) with endolaser photocoagulation of the right eye. The patient has well-controlled Type 2 diabetes and hypertension managed with oral agents — no systemic compromise beyond routine chronic disease management. An anesthesiologist personally administers general anesthesia via laryngeal mask airway. Anesthesia preparation begins at 8:02 AM; the patient is transferred to PACU at 10:14 AM — total anesthesia time of 132 minutes (8.8 time units, rounded to 8 units per Medicare’s 15-minute unit convention).
Correct Code Application
- CPT 00145 – AA – P2 (anesthesiologist personally performed; patient is P2 — mild systemic disease, controlled DM/HTN without end-organ compromise)
- 132 minutes reported in Box 24G on the CMS-1500
- ICD-10-CM H35.311 (nonexudative AMD) → Correction: H35.61 (retinal hemorrhage) or H36 (retinal disorders in diseases classified elsewhere, i.e., diabetic retinopathy) — confirm with surgeon’s pre-op diagnosis
- Total Medicare units billed: 6 (base) + 8 (time) = 14 units × $20.4976 CF = $286.97 approximate Medicare allowable
Common Mistake in This Scenario
- Incorrect: Billing the case as P3 (+1 unit for commercial payers) based solely on the diagnosis of diabetes, without documented evidence that diabetes creates a substantive increase in anesthetic risk.
- Why it fails: P3 requires documented evidence of significant systemic disease that is a substantive functional limitation — controlled DM/HTN in a functionally active 68-year-old typically meets P2. Upcoding to P3 without clinical documentation supporting functional limitation is a payer audit trigger and OIG compliance risk.
- Incorrect: Submitting the claim without a modifier. Without AA in position one, the claim is denied as a billing error.
Frequently Asked Questions About CPT Code 00145
Is CPT Code 00145 Still Valid for Use in 2026?
CPT code 00145 remains an active, billable anesthesia code with no descriptor changes for 2026. Coders should verify annually against the AMA CPT Professional Edition and the CMS Physician Fee Schedule Final Rule to confirm no modifications to base unit values or coverage policy have been applied.
How Is CPT 00145 Reimbursed Under Medicare?
Medicare reimburses CPT 00145 using the anesthesia unit formula: (Base Units + Time Units) × the applicable Medicare Anesthesia Conversion Factor, which is $20.4976 per unit for 2026 per the CY 2026 PFS Final Rule. Medicare does not add payment for physical status modifiers or qualifying circumstance codes — those additional units apply only under commercial payer contracts that explicitly recognize them.
What Is the Difference Between CPT 00145 and CPT 00142?
CPT 00142 covers anesthesia for lens surgery (including cataract extraction), while CPT 00145 covers vitreoretinal procedures targeting the posterior segment of the eye. Both carry 6 base units under the ASA RVG, but the correct code is determined by the surgical target documented in the operative note — not the diagnosis or provider preference. When both procedures occur under a single anesthetic, only the highest base unit code is billed with the combined time.
Does CPT 00145 Apply to In-Office Intravitreal Injections?
No. In-office intravitreal injections (CPT 67028) are typically performed with topical anesthesia only and do not involve a separate anesthesia provider. CPT 00145 applies when a qualified anesthesia professional manages the anesthetic care in an OR or procedure suite setting. Occasionally, intravitreal procedures are performed under MAC in an ASC — in those situations, MAC modifier (QS) may apply, but 00145 would still describe the base service if the anesthesia episode meets the threshold for full anesthesia management.
What Physical Status Modifier Should Be Used for a Diabetic Retinopathy Patient?
The correct physical status assignment depends on the patient’s functional status — not the diagnosis alone. A patient with controlled Type 2 diabetes and no systemic complications is typically P2. If the diabetic retinopathy patient has documented end-organ compromise (nephropathy, cardiovascular disease, peripheral neuropathy with functional limitation), P3 may be appropriate. P4 applies only when the systemic disease is a constant threat to life. Document the clinical basis for the assigned P-status in the pre-anesthesia evaluation note; it must be defensible on audit.
Can a CRNA Bill CPT 00145 Without Physician Supervision?
Yes, but only in states that have opted out of the CMS physician supervision requirement for CRNAs. In opt-out states, a CRNA may bill CPT 00145 with modifier QZ (CRNA without medical direction) and receive 100% of the applicable CRNA fee schedule rate. In non-opt-out states or under commercial payer contracts requiring supervision, the CRNA reports modifier QX and receives 50% of the allowed amount, with the supervising anesthesiologist reporting the complementary modifier (QK or QY) on a separate claim.
What Happens When a Vitreoretinal Procedure Is Combined With Cataract Surgery Under One Anesthetic?
When combined vitreoretinal and anterior segment surgery is performed under a single anesthetic administration, bill only the anesthesia code with the highest ASA base unit value using the total anesthesia time for both procedures. Since CPT 00142 (lens surgery, 6 units) and CPT 00145 (vitreoretinal, 6 units) share the same base unit value, the tiebreaker should follow ASA Crosswalk® guidance and payer-specific rules. When in doubt, query your MAC or reference the payer’s anesthesia policy for combined procedure billing.
Key Takeaways for Billing and Coding CPT 00145
- CPT 00145 is the correct anesthesia code for all vitreoretinal surgery — including PPV, scleral buckle, retinal detachment repair, and membrane peeling; it does not apply to anterior segment ophthalmic procedures
- Base unit value is 6 per the ASA Relative Value Guide® and CMS — among the higher values in the ophthalmology anesthesia subcategory
- Reimbursement follows the anesthesia unit formula: (Base + Time + Qualifying Units) × Conversion Factor — accurate time documentation is the single most audited element
- A provider payment modifier (AA, QK, QZ, QX, etc.) is mandatory in position one; claims without it will be denied
- Physical status modifiers (P1–P6) are required on all claims but only generate additional payment under commercial payer contracts that recognize them — verify by contract
- For combined ophthalmic procedures under a single anesthetic, bill only the highest base unit code with the total continuous time
- Vitreoretinal patients commonly present with diabetic comorbidities — careful and defensible P-status documentation protects against both underpayment and audit exposure
For further guidance on anesthesia billing documentation requirements, refer to the CMS Medicare Claims Processing Manual, Chapter 12 and the ASA Relative Value Guide®. NCCI bundling edit rules specific to anesthesia are published quarterly at CMS NCCI guidelines. Revenue cycle compliance teams should also review the OIG Work Plan for active anesthesia audit priorities.
