CPT Code 00148: Anesthesia for Ophthalmoscopy (Eye Examination) – Complete Billing & Coding Guide

CPT code 00148 describes anesthesia services provided for an ophthalmoscopy — a diagnostic examination of the interior structures of the eye, including the retina, optic disc, choroid, and vitreous. The code falls within the anesthesia for procedures on the eye subsection of the AMA CPT code set (range 00140–00148) and carries a base unit value of 4, reflecting the lower procedural complexity relative to surgical ocular interventions. It is most commonly billed when a patient cannot undergo an awake eye examination due to cognitive impairment, severe anxiety, pediatric age, or neurobehavioral conditions that prevent cooperation. Anesthesia professionals — including anesthesiologists and certified registered nurse anesthetists (CRNAs) — report this code using the standard base-plus-time-unit methodology under the Medicare Physician Fee Schedule (MPFS).

What Does CPT Code 00148 Mean?

CPT 00148 is defined by the AMA as: “Anesthesia for procedures on the eye; ophthalmoscopy.” In plain terms, it is the billing vehicle for anesthesia rendered when an ophthalmologist or other qualified clinician needs to perform a thorough retinal or fundoscopic examination on a patient who requires sedation or general anesthesia to complete the evaluation safely. Unlike surgical eye codes (00140–00147), this code is procedure-specific to diagnostic examination rather than a surgical intervention.

Key attributes at a glance:

• Billable status: Active, valid for billing in 2025 (no descriptor changes)
• Code category: Anesthesia — Procedures on the Head/Eye
• AMA base unit value: 4 base units
• Applicable setting: Outpatient hospital, ambulatory surgical center (ASC), or inpatient facility
• Provider type: Anesthesiologist (MD/DO) or CRNA, with or without medical direction
• Service category: Diagnostic/examination anesthesia — NOT surgical
• Reimbursement methodology: Base units + time units × anesthesia conversion factor

What Services and Procedures Does CPT 00148 Cover?

CPT 00148 encompasses the complete anesthesia service package — pre-anesthesia evaluation, intraoperative monitoring, and post-anesthesia care — delivered for an ophthalmoscopy. This includes indirect ophthalmoscopy, fundoscopic examination under anesthesia (EUA), and examination of the posterior segment of the eye. The code is frequently encountered in ophthalmology practices that serve pediatric patients, individuals with developmental disabilities, or adults with severe procedural anxiety.

Included clinical presentations and service types:

• Examination under anesthesia (EUA) for diagnostic retinal assessment
• Fundoscopic evaluation for retinopathy of prematurity (ROP) screening in premature neonates
• Posterior segment examination when tonometry or slit-lamp exam is not feasible awake
• Optic disc and macula evaluation in patients with neurobehavioral or cognitive conditions
• Forced duction testing combined with ophthalmoscopy when documented under the same anesthetic episode

What Does CPT 00148 Specifically Exclude?

This code does NOT cover the following — coding these scenarios incorrectly under 00148 is a leading audit trigger:

• Lens surgery anesthesia (CPT 00142): Cataract extraction and IOL insertion require 00142, not 00148
• Vitreoretinal surgery (CPT 00145): Pars plana vitrectomy and retinal detachment repair are surgical, not diagnostic
• Iridectomy (CPT 00147): Peripheral or laser iridectomy has its own dedicated code
• General eye surgery not otherwise specified (CPT 00140): Used when no more specific eye code applies
• The ophthalmoscopy procedure itself: The examination is billed by the ophthalmologist using the appropriate eye code (e.g., CPT 92018 or 92019); 00148 covers only the anesthesia component

When Is CPT 00148 the Right Code to Use?

Selecting CPT 00148 over neighboring eye anesthesia codes requires confirming that the underlying procedure is strictly diagnostic ophthalmoscopic examination — not a surgical intervention. In practice, coders frequently encounter charts where the anesthesia record lists “eye procedure” without specifying whether the case was diagnostic or surgical, requiring a deeper chart review before code assignment.

Step-by-step criteria for correct code selection:

1. Confirm the operative or procedural note documents an ophthalmoscopy or examination under anesthesia (EUA) as the primary service — not a surgical repair, extraction, or implantation.
2. Verify that anesthesia was medically necessary: the patient could not have tolerated an awake examination due to age, behavioral, or medical factors (documented in the pre-anesthesia evaluation).
3. Confirm the anesthesia provider is an anesthesiologist or CRNA — this code is not used to report surgeon-administered local or topical anesthesia (which is bundled into the surgical fee).
4. Rule out a more specific surgical code: if the ophthalmoscopy preceded or followed a surgical intervention under the same anesthetic, the surgical anesthesia code with the higher base unit value takes precedence.
5. Confirm the procedure occurred in an appropriate facility setting (hospital outpatient, ASC, or inpatient) — office-based general anesthesia requires additional documentation and state compliance review.

How Does CPT 00148 Differ From CPT 00140?

CPT 00140 is the “not otherwise specified” catch-all for anesthesia for eye procedures. If the record clearly documents an ophthalmoscopy or fundoscopic EUA, 00148 is the more specific and correct code. Using 00140 when 00148 applies violates the AMA CPT guidance to code to the highest level of specificity. The reimbursement impact is minimal since both codes carry the same 4 base units, but specificity is critical for payer edits and audit defensibility.

Note: Base unit values per CMS/VA Table H. Verify annually at the CMS Anesthesiologists Center.

What Documentation Is Required to Support CPT 00148?

Incomplete anesthesia records are among the top reasons claims for CPT 00148 are delayed or denied by Medicare Administrative Contractors (MACs). Thorough documentation serves dual purposes: it establishes medical necessity and it provides the time-unit audit trail.

What Must the Provider Document in the Anesthesia and Clinical Record?

• Pre-anesthesia evaluation: Completed by the anesthesia provider, documenting patient history, ASA physical status classification, medication review, and the specific rationale for why anesthesia is required for this examination (e.g., “Patient is a 4-year-old with ROP; unable to cooperate with awake fundoscopic exam”)
• Anesthesia time: The exact start time (when the anesthesia provider began preparing/attending to the patient) and end time (when the patient was transferred to post-anesthesia care). Time is typically recorded in minutes on the claim
• Intraoperative monitoring record: Continuous vital signs, agent/concentration, airway management, and any intraoperative events
• Post-anesthesia care note: Documentation of patient emergence, recovery milestones, and discharge status
• Medical necessity documentation: An ICD-10-CM diagnosis code that justifies the need for anesthesia (see supported ICD-10 codes in the MAC LCD, such as H35.10 for ROP or F84.0 for autism spectrum disorder affecting cooperation)
• Provider identity and supervision level: The claim must clearly reflect whether an anesthesiologist performed personally (AA modifier), directed a CRNA (QK/QY), or a CRNA performed independently (QZ) or under direction (QX)

How Do Physical Status Modifiers Affect Documentation Requirements?

The ASA Physical Status (PS) classification system assigns a severity level to the patient’s overall health. Physical status modifiers P1 through P6 are appended to the anesthesia code and may affect reimbursement — particularly P3 and above, which many commercial payers recognize for additional payment.

• P1: Normal healthy patient (routine pediatric EUA)
• P2: Mild systemic disease (e.g., controlled asthma in a child with ROP)
• P3: Severe systemic disease (e.g., premature neonate with cardiopulmonary complications)
• P4–P6: Reserved for life-threatening conditions or brain-dead organ donors — rare for ophthalmoscopy cases

In practice, the majority of CPT 00148 cases are P1 or P2 (pediatric EUA for ROP or developmental disability). P3 modifier use requires clinical documentation explicitly supporting the classification to avoid downcoding on audit.

What Are the Documentation Standards for Facility vs. Non-Facility Settings?

How Does CPT 00148 Affect Medical Billing and Reimbursement?

Anesthesia billing under CPT 00148 — and all codes in the 00100–01999 range — does not follow the relative value unit (RVU) methodology used for surgical and E&M codes. Instead, reimbursement is calculated using the base unit + time unit formula: (Base Units + Time Units) × Anesthesia Conversion Factor = Allowable Amount. Per CMS Anesthesia Base Unit Table H, CPT 00148 carries 4 base units. Time units are typically calculated as 1 unit per 15 minutes of anesthesia time. CMS publishes locality-specific conversion factors annually; the national Medicare anesthesia conversion factor for 2025 varies by MAC jurisdiction.

CPT 00148 Reimbursement Formula Breakdown

Note: Actual reimbursement varies by payer contract, geographic locality, and modifier. The example above is illustrative. Verify current rates via the CMS Physician Fee Schedule lookup tool.

What Modifiers Are Commonly Used With CPT 00148?

Are There Any Prior Authorization, Coverage Restrictions, or LCD Requirements?

Per CMS MAC LCD Article A57361 (Monitored Anesthesia Care), CPT 00148 is explicitly listed among codes that may involve MAC. When MAC is provided, the QS modifier is required. The LCD also specifies that anesthesia for otherwise routine procedures — including eye examinations — is not automatically covered; medical necessity must be demonstrated through a supporting ICD-10-CM diagnosis.

• ICD-10 codes that support medical necessity for 00148: H35.10 (ROP, unspecified), F84.0 (autism), F70–F79 (intellectual disabilities), F91.9 (combative patient), Z13.5 (encounter for screening for eye disorders), and others per the applicable MAC LCD
• Prior authorization: Most commercial payers require pre-authorization for facility-based anesthesia for a diagnostic exam — verify plan-specific requirements before scheduling
• CRNA supervision opt-out: Fourteen states have opted out of the Medicare CRNA physician supervision requirement. In these states, CRNAs may bill QZ without a supervising physician — but must verify state law and individual facility credentialing policies
• NCCI bundling: The anesthesia code for the ophthalmoscopy is separate from the surgeon’s procedure code; no NCCI edit bundles 00148 into the ophthalmologist’s examination CPT codes (92018/92019)

What CPT or HCPCS Codes Are Commonly Billed Alongside CPT 00148?

The following codes frequently appear on the same claim or same encounter as CPT 00148. Understanding the pairing context prevents bundling errors and claim rejections.

Which Code Combinations Trigger NCCI or CCI Edits?

Per the CMS National Correct Coding Initiative (NCCI) Policy Manual, Chapter 2, anesthesia services are subject to the following bundling principles:

• One anesthesia code per operative session: When multiple procedures occur under a single anesthetic, bill only the code with the highest base unit value. If a diagnostic EUA (00148, 4 BU) is combined with a vitreoretinal procedure (00145, 6 BU), report 00145 only with total time for both procedures.
• Do not report 00148 with 47 modifier: Modifier 47 (anesthesia by surgeon) is not applicable for ophthalmoscopy — topical or local anesthetic by the surgeon is bundled into the surgical fee, not separately reportable by the surgeon.
• Qualifying circumstances (99100, 99116, 99135, 99140) are NOT bundled: These are legitimately separately reportable when documented — but each requires supporting clinical documentation to withstand audit.

What Coding Errors Should You Avoid With CPT 00148?

Anesthesia billing errors for CPT 00148 generate disproportionate claim denials and audit flags relative to the code’s frequency, largely because the medical necessity threshold for sedating a patient for a diagnostic exam is higher than for surgical procedures.

1. Billing 00148 when a surgical procedure was actually performed: If the ophthalmoscopy leads to a same-session surgical intervention (e.g., laser photocoagulation), the surgical anesthesia code applies. Review the full operative record, not just the scheduled procedure.
2. Missing or incomplete anesthesia time documentation: Payers compute time units from the minutes recorded on the claim. Leaving the time field blank or using a default value results in underpayment or denial.
3. Incorrect modifier for provider type: Appending AA when the case was actually medically directed (QK scenario) triggers overpayment and post-payment audit risk. Each provider in a team model must apply the correct modifier per CMS direction rules.
4. Failing to document medical necessity for anesthesia: Auditors commonly flag 00148 claims where the patient is an adult with no documented cognitive or behavioral barrier to an awake exam. The pre-anesthesia evaluation must articulate why anesthesia was required.
5. Using 00140 instead of 00148: While the base unit value is the same (note: 00140 actually carries 5 BU vs. 4 BU for 00148 — using 00140 for a documented ophthalmoscopy overstates complexity and is not code-specific).
6. Omitting ICD-10 codes that support the need for anesthesia: The diagnosis code(s) on the claim must reflect why anesthesia was necessary — not just the eye condition being examined. Include behavioral, age-related, or systemic diagnosis codes alongside the ocular diagnosis.

What Do Auditors and RAC Reviewers Look for When Reviewing Claims With CPT 00148?

• Medical necessity of anesthesia: Is there documentation explaining why the patient could not cooperate with an awake exam?
• Anesthesia time accuracy: Does the time billed align with the operative timeline in the facility record?
• Provider modifier consistency: Does the modifier on the claim match the anesthesia record’s documentation of provider role and supervision level?
• Correct code specificity: Was the procedure truly an ophthalmoscopy/EUA, or was it a surgical intervention that should have been coded differently?
• Qualifying circumstance documentation: If 99100 was billed for extreme age, is the patient’s date of birth consistent with the age threshold (<1 year or ≥70 years)?

How Does CPT 00148 Relate to Other CPT Codes?

Understanding where 00148 sits within the anesthesia code family helps coders avoid both undercoding (using 00140 when 00148 is correct) and upcoding (using 00148 for surgical cases that require a higher-base-unit code).

What Is the Correct Code Sequencing or Reporting Order When CPT 00148 Appears With Other Codes?

1. List the primary anesthesia code first (00148): The anesthesia CPT code anchors the claim line.
2. Append the provider/supervision modifier: AA, QK, QX, QY, or QZ immediately following the anesthesia code.
3. Append the physical status modifier: P1–P6 as the next modifier in the string.
4. Append QS if MAC was provided: This signals the type of anesthesia delivered.
5. Report qualifying circumstances (99100 etc.) on a separate line: These are separate CPT codes, not modifiers — list them on their own claim line below the primary anesthesia code.

Real-World Coding Scenario — How CPT 00148 Is Applied in Practice

Scenario: A 3-year-old male presents to a pediatric ophthalmology ASC for a scheduled examination under anesthesia to evaluate for retinopathy of prematurity (ROP). The child was born at 26 weeks gestation. The anesthesiologist performs a pre-anesthesia evaluation, documents the patient as ASA P2 (mild systemic disease — former premature infant, now healthy), and administers general anesthesia via laryngeal mask airway. Anesthesia start time: 8:14 AM. The ophthalmologist completes a bilateral indirect ophthalmoscopy. No surgical intervention is required. Anesthesia end time: 8:47 AM (33 minutes). The PACU note documents uneventful emergence.

Correct Code Application

• Anesthesia CPT code: 00148 — ophthalmoscopy confirmed as the only service performed
• Provider modifier: AA — anesthesiologist personally performed
• Physical status modifier: P2 — mild systemic disease documented
• Time on claim: 33 minutes (2 full time units + partial; payer rounds per policy)
• Qualifying circumstance: 99100 appended on separate line — patient is under 1 year of age
• Supporting ICD-10: H35.10 (ROP, unspecified stage) + P07.30 (preterm newborn, history)
• Ophthalmologist bills separately: CPT 92018 (ophthalmological examination, new patient) under the surgeon’s NPI — no bundling conflict with 00148

Common Mistake in This Scenario

• Error 1 — Using CPT 00140 instead of 00148: Some coders default to 00140 (NOS) without reviewing the operative record. 00148 is more specific and, in this case, carries 1 fewer base unit (4 vs. 5) — meaning 00140 would actually overstate complexity and create audit exposure for upcoding.
• Error 2 — Omitting 99100: Failing to append the qualifying circumstance code for extreme age leaves reimbursement (2 additional units) on the table and misrepresents the encounter’s complexity.
• Error 3 — Missing medical necessity ICD-10: Submitting only the eye diagnosis without the prematurity code weakens the justification for why anesthesia — rather than an awake exam — was required.

Frequently Asked Questions About CPT Code 00148

What Is CPT Code 00148 Used For?

CPT code 00148 is used to report anesthesia services provided during an ophthalmoscopy — a diagnostic examination of the eye’s interior structures including the retina and optic disc. It is most commonly billed for examinations under anesthesia (EUA) in pediatric patients, individuals with developmental disabilities, or any patient who cannot safely undergo an awake fundoscopic evaluation. The code covers the full anesthesia service, from pre-anesthesia evaluation through post-anesthesia recovery.

How Many Base Units Does CPT 00148 Carry?

CPT 00148 carries 4 base units per the CMS/ASA nationwide anesthesia base unit crosswalk, which has remained unchanged through CY 2025. These base units represent the relative intensity and complexity of the anesthesia service for an ophthalmoscopy. Total reimbursement is calculated by adding base units to time units (1 per 15 minutes) and multiplying by the locality-specific anesthesia conversion factor published annually by CMS.

Can a CRNA Bill CPT 00148 Without Physician Supervision?

A CRNA may bill CPT 00148 without physician supervision in states that have opted out of the Medicare CRNA supervision requirement (14 states as of 2025) or in facilities where state law permits independent CRNA practice. In these cases, the CRNA appends modifier QZ and bills at 100% of the allowed amount under their own NPI. In states without an opt-out, a supervising physician must be involved and the appropriate direction modifiers (QX for directed CRNA, QY for one CRNA directed by one anesthesiologist) must be applied.

What Is the Difference Between CPT 00148 and CPT 00140?

CPT 00140 is the “not otherwise specified” code for anesthesia for eye procedures and carries 5 base units, while CPT 00148 is procedure-specific to ophthalmoscopy and carries 4 base units. When the clinical record documents an ophthalmoscopy or EUA, 00148 is the correct, more specific code. Using 00140 for a documented ophthalmoscopy overstates complexity and creates potential upcoding liability on audit — even though coders sometimes assume a higher-numbered code is “safer.”

Is CPT Code 00148 Valid for Use in 2025?

CPT code 00148 remains a valid, active code for billing in 2025 with no changes to its descriptor, base unit value, or coverage status. The AMA CPT Editorial Panel has not modified this code in recent update cycles. Coders should verify annually against the AMA CPT Professional Edition and the CMS Physician Fee Schedule to confirm no revisions have been applied. Per the CMS Anesthesiologists Center, anesthesia base units are unchanged for CY 2025.

What ICD-10 Codes Support Medical Necessity for CPT 00148?

Medical necessity for anesthesia during ophthalmoscopy is most commonly supported by diagnoses reflecting inability to cooperate with an awake examination. Per CMS MAC LCD Article A57361, supporting ICD-10 codes include H35.10 (retinopathy of prematurity, unspecified stage), F84.0 (autism spectrum disorder), F70–F79 (intellectual disabilities), F91.9 (conduct disorder / combative patient), and T88.8XXA (other complications of anesthesia — for pediatric age under 18 per MAC policy). Providers must document the specific reason anesthesia was required, not simply the ocular diagnosis being evaluated.

Can CPT 00148 and CPT 92018 Be Billed on the Same Encounter?

Yes — CPT 00148 and CPT 92018 (ophthalmological examination, new patient) can both appear on the same date of service because they are billed by different providers. The anesthesia professional (anesthesiologist or CRNA) bills 00148 for the anesthesia service; the ophthalmologist bills 92018 or 92019 for the examination itself. There is no NCCI bundling conflict because these represent distinct professional services rendered by distinct qualified clinicians.

Key Takeaways for Billing and Coding CPT 00148

• CPT 00148 = anesthesia for ophthalmoscopy (eye examination): Use it exclusively for diagnostic EUA — not surgical eye procedures
• 4 base units, unchanged for 2025: Reimbursement = (4 BU + time units) × locality-specific conversion factor
• Medical necessity documentation is non-negotiable: Document why the patient required anesthesia — not just the ocular diagnosis
• Provider modifier determines reimbursement rate: AA, QK, QX, QY, or QZ must reflect actual supervision and delivery arrangements
• QS modifier required for MAC: If monitored anesthesia care was provided rather than general anesthesia, append QS
• Don’t default to 00140: 00148 is the correct, specific code for ophthalmoscopy — 00140 carries 5 BU and applies only when no specific code fits
• Bill 99100 separately for extreme age: Neonatal ROP exams in patients under 1 year qualify — don’t leave 2 additional units unreported

For current reimbursement rates and locality-specific conversion factors, visit the CMS Anesthesiologists Center and the CMS Physician Fee Schedule lookup tool. For payer-specific MAC and coverage guidance, consult CMS MAC LCD Article A57361 on Monitored Anesthesia Care. For official CPT descriptor language, refer to the AMA CPT Professional Edition.