Coding Emergency Services

Documents Required

• Complete ED physician note (history, exam, MDM, disposition)
• Nursing triage assessment and vital signs documentation
• Procedure notes for all ED procedures performed
• Critical care time documentation (start time, end time, total time, activities)
• Observation orders and status documentation (if applicable)
• Admission orders and H&P (if admitted from ED)
• Trauma activation documentation (if applicable)
• Radiology, laboratory, and other diagnostic results

Step 1 — Select the ED E/M Code Level (99281–99285)

Apply 1995/1997 Documentation Guidelines for ED visits.

• 99281 — Problem-focused: Self-limited or minor problem. Brief HPI, limited exam (1 body area or organ system), straightforward MDM.
• 99282 — Expanded problem-focused: Low to moderate severity. Brief HPI, limited exam (affected area + related systems), low complexity MDM.
• 99283 — Expanded problem-focused: Moderate severity. Extended HPI, extended exam (2–7 organ systems), moderate complexity MDM.
• 99284 — Detailed: High severity without immediate threat to life. Extended HPI, detailed exam (extended exam of affected area + related systems, or 8+ organ systems), moderate complexity MDM.
• 99285 — Comprehensive: Immediate significant threat to life or function. Comprehensive HPI, comprehensive exam (8+ organ systems with complete exam of each), high complexity MDM.

Key ED-specific rules:

• New vs. established patient distinction does NOT apply — all ED visits use the same code set regardless of prior visits.
• ED E/M codes can be billed by the ED physician even if the patient is subsequently admitted — the ED service is separately billable from the admitting physician's initial hospital care.
• If the ED physician admits the patient, do NOT bill both an ED E/M and an initial hospital care E/M — bill only the initial hospital care code (99221–99223) with the ED documentation combined.

Step 2 — Code Critical Care Services (99291–99292)

Apply critical care time-based billing rules strictly.

• 99291: First 30–74 minutes of critical care. Requires a minimum of 30 minutes.
• 99292: Each additional 30 minutes beyond the first 74 minutes.
• Time does not need to be continuous but must be documented with total time spent.

Time calculation:

Critical care definition: Direct delivery by a physician of medical care for a critically ill or injured patient where illness/injury acutely impairs one or more vital organ systems with a high probability of imminent or life-threatening deterioration.

Procedures bundled into critical care time (do NOT bill separately):

• Chest X-ray interpretation (71045/71046)
• ABG interpretation (blood gas analysis)
• Pulse oximetry (94760–94762)
• Ventilator management (94002–94004)
• Vascular access procedures (36000, 36410, 36415, 36591, 36600)
• CPR (92950)
• Temporary transcutaneous pacing (92953)
• Gastric intubation (43752, 43753)
• Bladder catheterization (51701, 51702)

Procedures NOT bundled (bill separately and subtract time from critical care):

• Intubation (31500)
• Central line placement (36555–36573)
• Chest tube insertion (32551)
• Lumbar puncture (62270)

Step 3 — Code ED Procedures

Assign CPT codes for procedures performed during the ED visit.

• Wound repair: Simple (12001–12021), Intermediate (12031–12057), Complex (13100–13160). Measure wound length in centimeters. Aggregate wounds of the same complexity in the same anatomic group.
• Fracture/dislocation management: Code based on type (closed/open), manipulation (with/without), and anatomic site. Example: 25600 (closed treatment distal radius fracture without manipulation).
• Incision and drainage: 10060 (simple I&D) vs. 10061 (complicated I&D — multiple, deep, or extensive).
• Foreign body removal: Based on depth and complexity — superficial (10120), deep/complicated (10121), eye (65205–65265).
• Conscious sedation: 99151–99153 by the performing physician; 99155–99157 by a different provider. Document start time, end time, monitoring intervals.
• When billing ED E/M + procedure on the same date, evaluate whether modifier 25 is needed for the E/M.

Step 4 — Handle Observation Services

Apply observation coding rules for ED-to-observation transitions.

• Observation status: Place of service 22 (on-campus hospital outpatient). Observation services are outpatient, not inpatient.
• Initial observation care (99218–99220): Billed by the physician who orders observation. Includes all E/M services on the date observation begins.
• Observation discharge (99217): Billed on the date the patient is discharged from observation (if different from admission date).
• Same-day admit/discharge from observation (99234–99236): If the patient is admitted to and discharged from observation on the same calendar date.
• ED E/M + Observation: If a different physician sees the patient in the ED and a different physician admits to observation, each physician bills their own service. If the SAME physician provides ED and observation care, bill only the observation admission code (not both ED E/M and observation).
• Observation to inpatient conversion: If the patient is admitted to inpatient from observation, bill only the initial inpatient code (99221–99223). The observation care is bundled.

Step 5 — Facility Coding Considerations (UB-04)

Apply facility-specific ED coding rules.

• Revenue code 0450: ED general classification (facility charge for ED use).
• Revenue code 0451–0459: Specific ED service categories (EMTALA screening, beyond initial examination, etc.).
• Trauma activation fee (revenue code 068x): Billed when a trauma team is activated per hospital protocol. Requires documented trauma activation criteria. Only one trauma activation fee per ED visit.
• Facility E/M: Many hospitals use the ACEP (American College of Emergency Physicians) facility ED E/M leveling system or a locally developed system — this is separate from professional E/M coding.
• APC grouping: ED visits group into APCs for Medicare OPPS payment. Higher-level E/M codes group into higher-paying APCs. Composite APCs apply to ED visits with certain combinations of services.
• EMTALA compliance: All patients presenting to the ED must receive a Medical Screening Examination (MSE) regardless of ability to pay — the facility codes this even if no professional E/M is generated.

Checkpoint B — Review

• ED E/M code level is supported by 1995/1997 Documentation Guidelines (not 2021+ framework)
• Critical care time is documented with total minutes and reflects only qualifying activities
• Procedures bundled into critical care are NOT separately billed
• Procedures NOT bundled are separately coded with time deducted from critical care total
• Observation coding follows same-physician vs. different-physician rules
• Observation-to-inpatient conversion billing is correct (only initial inpatient code)
• Modifier 25 is applied appropriately for ED E/M + same-day procedure
• ICD-10-CM diagnoses reflect the ED encounter (not just the admitting diagnosis if admitted)

Quality Audit

• Critical care time documentation includes start time, activities performed, and total time
• ED E/M level distribution matches expected acuity mix (bell curve centered around 99283–99284)
• Procedure coding is complete — all documented procedures are captured on the claim
• Split billing rules are followed when ED physician also admits the patient
• Observation hours are tracked for medical necessity (CMS 24-hour/48-hour benchmarks)
• Trauma activation fees are billed only when documented activation criteria are met
• Teaching physician attestation requirements are met for resident-provided ED care

Guidelines

• Apply 1995 or 1997 CMS Documentation Guidelines for ED E/M code selection (not 2021+ E/M framework)
• Follow CMS Medicare Claims Processing Manual Chapter 12 §30 for critical care billing rules
• Reference AMA CPT guidelines for critical care (99291–99292) including bundled procedure list
• Apply CMS OPPS rules for facility ED coding and APC assignment
• Follow ACEP guidelines for facility E/M leveling if hospital uses that methodology
• Comply with EMTALA requirements for medical screening examination documentation
• Never bill critical care for time spent on procedures that are separately reportable — deduct that time
• Mark with [VERIFY] any critical care time documentation that lacks specific start/end times or total minutes
• Include disclaimer that ED coding rules are complex and payer-specific variations may affect reimbursement