CPT® Code 00840

Quick Reference

• Code definition: 00840 covers anesthesia for intraperitoneal surgical and laparoscopic procedures within the lower abdominal peritoneal cavity when no more specific anesthesia code exists. The "not otherwise specified" qualifier is load-bearing: always exhaust more specific codes first.
• Key billing rule: Anesthesia is billed using a unit-based formula: (Base Units + Time Units + Modifying Units) x Anesthesia Conversion Factor. For 00840, base units are 7 (per ASA Relative Value Guide; verify annually at asahq.org). Time is reported in minutes on the CMS-1500; the payer converts to units at 1 unit per 15 minutes [1].
• Modifier essentials: A supervision or role modifier is required on every Medicare anesthesia claim. AA (personally performed), QK/QX (medically directed, 2-4 concurrent), QY/QX (medically directed, 1 CRNA), and QZ (independent CRNA) are the core set. Physical status modifiers (P1-P6) are appended for all payers but carry no additional Medicare payment units [1].
• Documentation must-have: Anesthesia start and stop times in minutes, recorded in the anesthesia record, must match claim submission exactly. Time discrepancies are the leading OIG overpayment finding for anesthesia claims [2].
• Top confusion point: 00840 covers intraperitoneal lower abdominal procedures; 00860 covers extraperitoneal lower abdominal procedures including the urinary tract. Using 00840 for a cystoscopy or retroperitoneal dissection is a systematic miscoding error. Review the operative note for peritoneal access before assigning either code.
• Payer alert: Medicare does not pay physical status modifiers (P1-P6) as additional units. Many commercial payers do pay P3 (+1 unit) through P5 (+3 units). Verify individual payer contracts before assuming additional payment for high-acuity physical status [1].
• Add-on code: 0887T (end-tidal control of inhaled anesthetic agents) may be reported in addition to 00840 when applicable per CPT guidelines.

When to Use This Code

00840 applies when anesthesia is provided for a surgical procedure that: (1) is performed within the lower abdominal peritoneal cavity, (2) includes or could include laparoscopic access, and (3) has no more specific anesthesia code in the 00800-00882 range.

Clinical indications that map to 00840 include laparoscopic hysterectomy (total, supracervical), myomectomy, oophorectomy, salpingectomy, salpingo-oophorectomy, laparoscopic appendectomy, laparoscopic sigmoid or left colectomy, diagnostic laparoscopy of the pelvis or lower abdomen, and laparoscopic lysis of adhesions or peritoneal biopsy. Open lower abdominal intraperitoneal procedures with no dedicated anesthesia code also fall here.

Scope boundaries are defined by anatomy and approach. The lower abdominal peritoneal cavity includes the sigmoid colon, rectum, appendix, peritoneal surface of the bladder, uterus, ovaries, fallopian tubes, and pelvic peritoneum. The key exclusion is any procedure that accesses the retroperitoneal space, urinary tract, or abdominal wall without entering the peritoneum. Hernia repairs in the lower abdomen have their own code (00830) and should never fall to 00840 NOS.

Provider and setting context: 00840 is billed by the anesthesiologist or CRNA, never the operating surgeon. It is reported on the professional fee schedule, not bundled into facility charges. The APC status indicator for 00840 is "Packaged" on the hospital outpatient side. The code applies in hospital ORs, ambulatory surgery centers, and outpatient procedure suites.

Anesthesia time rules: Time begins when the anesthesiologist begins preparing the patient for induction in the OR or equivalent area, and ends when the anesthesiologist is no longer in personal attendance and the patient has been safely transferred to post-anesthesia care staff [1]. Pre-operative and post-operative evaluation visits are separate services and do not count toward anesthesia time. Time is continuous; breaks in attendance (e.g., leaving the room) must be documented and can jeopardize medical direction claims.

Code Differentiation Table

The 00840-vs-00860 distinction is the highest-risk differentiation error in this range. The operative note is the only reliable source. Look for language describing peritoneal entry, trocar placement into the peritoneal cavity, or visualization of intraperitoneal structures. If the note describes a retroperitoneal dissection or transurethral approach without peritoneal access, 00860 or a urologic anesthesia code applies, not 00840.

Billing & Modifier Rules

Anesthesia Payment Formula

Payment for 00840 is calculated as:

(Base Units + Time Units + Modifying Units) × Anesthesia Conversion Factor

Base units for 00840 are assigned by the ASA Relative Value Guide (reported as 7 units; verify current value annually at asahq.org, ASA membership required) [3]. Time units accrue at 1 unit per 15 minutes; partial units are reported per payer policy (some payers round, others prorate). The anesthesia conversion factor is updated annually in the CMS Physician Fee Schedule Final Rule and varies by geographic locality [4].

Supervision Modifiers

CMS requires a supervision or role modifier on every anesthesia claim. Choosing the wrong modifier is auditable via cross-referencing anesthesiologist and CRNA claims for the same case.

QK paired with QX yields 100% of the allowed amount split equally between the directing physician and the directed CRNA. AD carries severe payment reduction to 3 base units only and is an OIG audit target; documentation rarely substantiates more than 4 concurrent medically directed cases [2].

Physical Status Modifiers

P1 through P5 are appended to 00840 for all payers. Medicare treats these as informational only; no additional units are paid. Commercial payers frequently pay P3 (1 additional unit), P4 (2 additional units), and P5 (3 additional units) per ASA RVG values. Verify each payer contract. P6 (brain-dead organ donor) is not billable.

Medical Direction: Seven Required Activities

To support QK or QY, the directing physician must document all seven required activities for each medically directed case [1]:

1. Perform pre-anesthetic examination and evaluation
2. Prescribe the anesthesia plan
3. Personally participate in the most demanding parts, including induction and emergence
4. Ensure procedures are performed only by qualified individuals
5. Monitor the course of anesthesia at frequent intervals
6. Remain physically present and available for immediate diagnosis and treatment of emergencies
7. Provide indicated post-anesthesia care

A single undocumented activity invalidates the medical direction claim and triggers recoupment on audit. Absence from induction or emergence is the most commonly cited deficiency.

Add-On Codes

0887T (end-tidal control of inhaled anesthetic agents and oxygen to assist anesthesia care delivery) is reported in addition to 00840 per CPT guidelines when this technology is used. It is listed separately; do not report it as a standalone code.

Qualifying circumstance add-on codes are listed separately in addition to 00840 when clinically supported:

• 99100: Patient under 1 year or over 70 years of age (MUE: 1 per day)
• 99116: Total body hypothermia (rare with lower abdominal procedures)
• 99135: Controlled hypotension
• 99140: Emergency conditions where delay would significantly increase risk to life

Multiple qualifying circumstances may be billed together when each condition independently exists (e.g., 99100 for age and 99140 for emergency on the same claim). The clinical record must affirmatively support each qualifying circumstance claimed.

Documentation Essentials

The anesthesia record is the primary audit document. It must contain:

• Exact start and stop times in minutes, matching what is submitted on the claim. CMS and MACs audit time against operative records; inflated time is the most common OIG anesthesia overpayment finding [2].
• Pre-anesthesia evaluation with patient history, physical examination findings, and ASA physical status assignment, documented before the procedure.
• Intraoperative monitoring record showing continuous vital signs, oxygen saturation, end-tidal CO2, and temperature at intervals consistent with the standard of care.
• Drugs and dosages with administration times.
• Post-anesthesia evaluation note confirming patient status at transfer.
• Informed consent documentation.

For medically directed cases (QK/QY), each of the seven required activities must appear in the record by name or clear implication. A note stating "present for induction and emergence" satisfies two activities; a checklist embedded in the anesthesia record is common practice and acceptable when completed contemporaneously.

For qualifying circumstances, the record must connect the clinical condition to the code. For 99140 (emergency), document explicitly why delay would have increased risk to the patient; do not rely on the surgical team's characterization of urgency alone.

Audit red flags specific to 00840:

• Anesthesia time exceeds the expected operative duration without a documented complication or extraordinary circumstance
• QK or QY billed without a corresponding CRNA claim or without documentation of all seven activities
• 00840 billed for a procedure that has a more specific anesthesia code (e.g., 00830 for hernia repair)
• 99140 billed for cases scheduled in advance without emergency documentation

Medicare, Commercial & Medicaid Payer Rules

Medicare

Anesthesia for medically necessary intraperitoneal lower abdominal surgery is covered when the underlying surgical procedure is covered [5]. There is no national NCD specific to anesthesia for lower abdominal procedures; coverage follows the covered surgical indication.

CMS does not maintain an LCD for 00840 itself. MAC-specific LCDs governing anesthesia services may apply by jurisdiction; search the CMS Medicare Coverage Database by procedure code 00840 and your MAC locality to confirm. Pre-anesthesia evaluation is a covered service when performed on the day before or day of surgery.

The anesthesia conversion factor is updated annually in the CMS Physician Fee Schedule Final Rule and varies by locality via Geographic Practice Cost Indices [4]. Verify the current year value before setting contract rates or estimating payment.

APC status for 00840 is "Packaged" under the hospital outpatient prospective payment system. On the facility side, anesthesia is typically packaged into the APC rate for the surgical procedure; the professional anesthesia claim is separate.

CRNA opt-out states: CMS has approved opt-out of the physician supervision requirement for CRNAs in a number of states. In opt-out states, independent CRNAs bill QZ without a supervising physician requirement. This affects modifier selection but not code 00840 itself. Confirm current opt-out status with your MAC before allowing unsupervised QZ billing in a given state.

Commercial Payers

The primary commercial divergence from Medicare is physical status modifier payment. Most commercial contracts recognize P3 through P5 as additional billable units; confirm this in writing per contract before billing.

Some commercial payers apply pre-authorization requirements for elective gynecologic laparoscopic procedures. Authorization is typically obtained by the surgeon for the surgical procedure; verify whether the payer requires separate authorization for the anesthesia service.

Commercial payers do not uniformly accept qualifying circumstance add-on codes (99100, 99116, 99135, 99140). Payer-specific policies govern whether these codes are recognized and paid separately. Submit with clinical documentation attached when payer policy is unclear.

Common Denials & Prevention

Incorrect anesthesia code (wrong site/approach) Using 00840 for a procedure that is extraperitoneal, retroperitoneal, or accesses the urinary tract without peritoneal entry. Payers may not catch this on initial processing, but it surfaces on audit. Prevention: Establish a mapping table linking common lower abdominal surgical CPT codes to their correct anesthesia code before claim submission. Flag any case where the surgical code falls in the urologic or retroperitoneal range for manual review.

Time discrepancy between record and claim Anesthesia start or stop time on the claim does not match the time documented in the anesthesia record. CMS and MACs routinely compare claim time against operative documentation during audits; even 15-minute discrepancies generate recoupment demands [2]. Prevention: Implement a reconciliation step between the anesthesia record and the billing system before claim generation. Verify total minutes; recalculate units before submission.

Medical direction modifier without complete seven-activity documentation QK or QY billed but the anesthesia record does not document all seven required activities, or the physician was not present at induction or emergence. Prevention: Use a structured intraoperative documentation template that explicitly captures each of the seven activities with time stamps. Train anesthesiologists that departure before emergence, even briefly, disqualifies the entire case from medical direction billing [1].

Qualifying circumstance without clinical support 99140 (emergency) billed for a case that was scheduled in advance, or 99100 billed for a patient between ages 1 and 70. Prevention: Apply qualifying circumstance codes only when the anesthesia record contains explicit clinical language supporting the condition. For 99140, the record must state that delay in surgery would have increased risk to the patient's life.

Physical status upcode without documentation Commercial claim submitted with P3 or P4 appended without documentation of the specific systemic disease and its severity in the pre-anesthesia evaluation. Prevention: The pre-anesthesia evaluation must name the condition, its severity, and its clinical impact. "Hypertension, controlled" supports P2; "Hypertension with end-organ damage" supports P3. Unspecified "comorbidities" without detail will not sustain P3 or higher on appeal.

Coding Scenarios

Scenario 1: Elective Laparoscopic Oophorectomy, ASA P1

A 45-year-old woman with no significant comorbidities (ASA P1) undergoes elective laparoscopic right oophorectomy for an ovarian cyst. Anesthesia time: 75 minutes. The anesthesiologist personally performs, no CRNA involved.

Correct coding: 00840-AA-P1. Calculation: 7 base units + 5 time units (75 min / 15) = 12 units x conversion factor. Surgeon bills 58661 separately.

Why: The ovarian cyst resection is an intraperitoneal lower abdominal procedure with no more specific anesthesia code. AA confirms personal performance. P1 is informational only; adds no Medicare payment units.

Scenario 2: Emergency Laparoscopic Appendectomy, Age 73, ASA P3

A 73-year-old man with controlled type 2 diabetes and hypertension (ASA P3) presents with acute appendicitis. The surgeon determines emergency surgery is required; delay would increase peritonitis risk. Anesthesia time: 90 minutes. Anesthesiologist personally performs.

Correct coding: 00840-AA-P3 + 99100 + 99140. Calculation: 7 base + 6 time units (90 min) + qualifying circumstance units per payer contract x conversion factor. Surgeon bills 44970 separately.

Why: Both qualifying circumstances independently apply: age over 70 (99100) and documented emergency condition where delay increases risk (99140). P3 adds no Medicare units but is required on all anesthesia claims. The anesthesia record must explicitly state why delay was clinically dangerous to support 99140.

Scenario 3: Medically Directed CRNA, Laparoscopic Hysterectomy

An anesthesiologist is medically directing a CRNA providing anesthesia for a laparoscopic hysterectomy (58570) on a 52-year-old woman (ASA P2). The physician is concurrently directing one other case (2 concurrent). Anesthesia time: 120 minutes.

Correct coding: Anesthesiologist bills 00840-QK-P2 (50% of allowed). CRNA bills 00840-QX-P2 (50% of allowed). Calculation for each: 7 base + 8 time units (120 min) x conversion factor x 50%.

Why: QK (physician directing 2-4 concurrent) and QX (CRNA under direction) together yield 100% of the allowed amount split evenly. All seven medical direction activities must be documented for QK to be valid. Absence from induction or emergence on either case disqualifies the medical direction claim entirely.

Scenario 4: Wrong Code Identification, Retroperitoneal Lymph Node Dissection

A coder receives an anesthesia claim coded as 00840 for a bilateral retroperitoneal lymph node dissection (RPLND). The operative note describes a retroperitoneal approach without peritoneal entry.

Correct coding: 00860 (anesthesia for extraperitoneal procedures in lower abdomen), not 00840.

Why: RPLND accesses the retroperitoneal space; the peritoneal cavity is not entered. 00840 is intraperitoneal only. Using 00840 when the procedure is retroperitoneal misrepresents the service and constitutes incorrect code selection. Review the operative note before finalizing any lower abdominal anesthesia claim where peritoneal access is not explicit.

Related Codes

• 00800 (CPT): Anesthesia, lower anterior abdominal wall; NOS. Use for wall-based procedures without peritoneal access.
• 00820 (CPT): Anesthesia, lower posterior abdominal wall. Use for posterior wall procedures.
• 00830 (CPT): Anesthesia, hernia repairs in lower abdomen; NOS. More specific code; use instead of 00840 for all lower abdominal hernia repairs.
• 00860 (CPT): Anesthesia, extraperitoneal procedures including urinary tract; NOS. Critical sibling; use for retroperitoneal and urologic lower abdominal cases.
• 99100 (CPT): Qualifying circumstance, extreme age. Add-on to 00840 for patients under 1 or over 70.
• 99140 (CPT): Qualifying circumstance, emergency conditions. Add-on to 00840 when emergency is documented.
• 0887T (CPT): End-tidal control of inhaled anesthetic agents. Add-on to 00840 when technology is used.
• 44970 (CPT): Laparoscopic appendectomy. Commonly paired surgical code (billed by surgeon separately).
• 58661 (CPT): Laparoscopic removal of adnexal structures. Commonly paired surgical code for oophorectomy and salpingectomy cases.
• 58570 (CPT): Laparoscopic total hysterectomy, uterus 250 g or less. Commonly paired surgical code for laparoscopic hysterectomy cases.
• 49320 (CPT): Diagnostic laparoscopy of abdomen and peritoneum. Commonly paired surgical code for diagnostic cases.

Sources

1. CMS Medicare Claims Processing Manual, Pub. 100-04, Chapter 12 — CMS — Authoritative rules for anesthesia billing formula, time definition, supervision modifiers (AA/AD/QK/QX/QY/QZ), seven medical direction activities, CRNA billing, and documentation requirements.

2. HHS OIG Work Plans: Anesthesia Services — HHS OIG — Recurring compliance focus areas for anesthesia: time reporting accuracy, medical direction documentation, concurrent procedure limits, and qualifying circumstance support.

3. ASA Relative Value Guide — American Society of Anesthesiologists — Official source for anesthesia base unit values by CPT code; updated annually; ASA membership required.

4. Federal Register: CY 2025 Physician Fee Schedule Final Rule — CMS/Federal Register — Annual update to anesthesia conversion factor and geographic payment adjustments.

5. CMS Medicare Coverage Database — CMS — Search by CPT 00840 and MAC jurisdiction for applicable LCDs governing anesthesia coverage.