ER Billing Compliance 2026: Avoiding High-Risk Denial Triggers in Emergency Department Coding

ER billing compliance in 2026 means coding every emergency department visit to the level the record actually supports, because payers now recalculate level 4 and level 5 claims automatically and federal auditors are reviewing ED codes billed in the wrong setting. The highest-risk denial triggers are unsupported 99284 and 99285 levels, missing diagnosis and workup codes, modifier 25 errors, critical care billed with an ED visit, split/shared visits without modifier FS and ED codes reported with the wrong revenue code or place of service.

This guide explains each trigger, which payers are acting on it in 2026, including Texas plans, and the documentation and claim checks that keep emergency department coding clean. It draws on current payer policies from UnitedHealthcare, Superior HealthPlan and Community Health Choice, a March 2026 HHS OIG audit and the CY 2026 Medicare Physician Fee Schedule.

ER Billing Compliance in 2026 at a Glance

• Biggest trigger: level 4 and 5 ED visits (99284, 99285, G0383, G0384). Payers use tools such as the Optum EDC Analyzer to recalculate the level and pay less.
• Texas focus: Superior HealthPlan and Community Health Choice apply ED leveling to hospital and freestanding ERs. Community Health Choice’s policy took effect October 18, 2026.
• Federal audits: HHS OIG found over $15 million in improper and potentially improper payments for ED codes billed with non-ED settings.
• Professional coding: ED E/M levels are chosen by medical decision making (MDM). Time does not count for 99281 to 99285.
• Same-day services: critical care, procedures and split/shared visits each have their own modifier and documentation rules.
• Best defense: complete diagnosis and procedure coding, a written facility leveling policy, pre-bill audits and fast, documented appeals.

Why ER Billing Compliance Matters More in 2026

Emergency departments have always carried more billing risk than most settings. Visits are unscheduled, documentation is written under pressure and a single patient can generate an E/M service, procedures, imaging and critical care in one encounter. In 2026 three things raised the stakes:

• Automated leveling is spreading. UnitedHealthcare, Superior HealthPlan and Community Health Choice all review facility level 4 and level 5 ED claims and adjust them to a calculated level when the diagnosis and workup codes do not support the billed level.
• Federal auditors are looking at ED codes. A March 2026 HHS OIG audit found Medicare paid $922,524 to physicians for ED procedure codes billed with non-emergency places of service and $14.2 million in potentially improper payments to hospitals that used non-emergency revenue codes.
• Commercial downcoding has gone mainstream. Cigna’s E/M downcoding policy, which started October 1, 2025 for high-level office and consult codes, showed how quickly payers will reduce E/M levels on a claim without asking for records first.

The result is that ER billing compliance is no longer only about avoiding fraud findings. It is about protecting revenue from automated reductions that hit correctly coded claims when the claim itself does not tell the full story.

How ED E/M Levels Work: Professional vs Facility

Emergency department visits are coded twice: once for the physician or advanced practice provider and once for the facility. The two levels are chosen in different ways, which is one of the most common sources of confusion and denials.

	Professional claim (CMS-1500 / 837P)	Facility claim (UB-04 / 837I)
Codes	99281 to 99285	99281 to 99285, or G0380 to G0384 for Type B EDs
Level based on	Medical decision making only. Time does not apply.	Hospital resources used, under the facility’s own leveling guidelines
Place of service / revenue code	POS 23 for a hospital ED	Revenue code 045X
Main payer check	MDM documentation, modifier 25, same-day services	Diagnosis codes and workup codes compared with the billed level

Since the 2023 CPT changes, the professional level is set by MDM: the number and complexity of problems, the data reviewed and analyzed, and the risk of patient management. A level 5 visit needs high MDM, not just a sick-looking patient or a long note. On the facility side, CMS lets each hospital write its own leveling rules, but they must be consistent, based on hospital resources and applied to every patient, so a level 5 facility charge should be reproducible from the chart.

9 High-Risk Denial Triggers in Emergency Department Coding

These are the patterns most likely to cause a downcode, denial or audit finding on ED claims in 2026, with the fix for each.

1. Level 4 and level 5 visits without supporting codes

Payer tools read the claim, not the chart. The Optum EDC Analyzer used by UnitedHealthcare and Superior HealthPlan sets the expected level from three things: the presenting problem diagnosis, the diagnostic services billed (labs, x-ray, EKG, CT, MRI, ultrasound) and patient complexity from secondary and external cause codes. If a 99285 facility claim lists one vague diagnosis and no workup codes, it will be cut even if the patient was very sick.

Tip: Make sure every lab, imaging study and EKG performed in the ED is on the claim, and code comorbidities that affected care. Missing codes are the number one reason correct level 5 claims get downcoded.

2. Modifier 25 on an E/M with a procedure

When the ED provider performs a procedure such as a laceration repair, splinting or a joint reduction, the E/M visit is only separately payable when it goes beyond the normal pre-procedure evaluation. Modifier 25 on every E/M with a procedure is a classic audit flag, and same-day E/M and minor procedure billing is a current OIG audit focus.

Example: A patient with chest pain gets a full cardiac workup and also has a forearm laceration repaired. The chest pain evaluation supports a separate E/M with modifier 25. A patient seen only for the laceration usually does not.

3. Critical care billed with an ED visit

Critical care (99291, 99292) requires at least 30 minutes of qualifying critical care time and a critically ill or injured patient. Medicare allows an ED visit and critical care on the same day by the same practitioner only when the ED visit happened first, before the patient needed critical care, and the time does not overlap. Modifier 25 goes on the critical care code. Critical care billed the same day as ED services has long been an approved CMS Recovery Audit topic, so time and the reason for critical care must be documented separately.

4. Split/shared visits without modifier FS

When a physician and an APP from the same group both see the patient, the visit is billed by whoever performed the substantive portion, measured by more than half the total time or by the substantive part of MDM. Medicare requires modifier FS on split/shared claims, and the billing practitioner must document and sign their part. ED visits are eligible because the ED is a facility setting (POS 23).

5. ED codes with the wrong setting

The OIG audit found ED procedure codes billed by physicians with non-emergency places of service and by hospitals with non-emergency revenue center codes. ED E/M codes belong with POS 23 on professional claims and revenue code 045X on facility claims. Urgent care, clinic or observation settings need their own codes.

6. Weak or missing diagnosis coding

Coding only a symptom when a final diagnosis was reached, leaving out comorbidities or skipping external cause codes for injuries all lower the calculated level and can trigger medical necessity denials such as CO 50. Code the chief complaint, the final diagnosis and every condition that changed management.

7. Retroactive “non-emergency” denials

Some payers deny or reduce ED claims based on the final diagnosis. Under the prudent layperson standard, emergency coverage depends on the symptoms a reasonable person would see as an emergency, not on what the final diagnosis turned out to be. The No Surprises Act also bars prior authorization for emergency services. Keep the presenting symptoms clearly documented so these denials can be overturned.

8. Unbundled facility charges

Facility claims that bill supplies, nursing time or routine services separately when they are part of the ED level, or that report procedures already included in another service, run into NCCI edits and CO 97 bundling denials. Your charge master and leveling policy should state which services are bundled into each level.

9. Copy-forward and template documentation

EHR templates that pull the same review of systems, exam and “high risk” statements into every note make level 5 look routine. Auditors compare notes across patients. Documentation must describe this patient’s problems, the data actually reviewed and the real management decisions.

Payer ED Leveling Policies to Watch

These policies apply to facility claims (UB-04) for level 4 and level 5 ED visits. Each one lets the payer pay a lower level than you billed.

Payer	Codes reviewed	How the level is set	Main exclusions
UnitedHealthcare commercial	99284, 99285, G0383, G0384	Optum EDC Analyzer: diagnosis, workup, complexity	Admission, same-visit surgery, transfer, critical care, under age 2, death in ED
Superior HealthPlan (Texas)	99284, 99285, G0383, G0384	Optum EDC Analyzer; applies to hospital and freestanding EDs	Same as UnitedHealthcare
Community Health Choice (Texas)	99284, 99285	Facility resource use and peer risk adjustment; effective October 18, 2026	Not listed; records needed for appeal

Community Health Choice’s policy covers its STAR, STAR+PLUS, CHIP, Medicare Advantage and Marketplace plans and applies to in-network and out-of-network facilities, including freestanding EDs. Reconsiderations must include medical records or the original decision stands.

Texas ER and Freestanding ER Compliance

Texas has more freestanding emergency rooms than any other state, and they face rules on top of normal ER billing compliance:

• Patient disclosures. Texas HB 2041 requires freestanding ERs to give patients a written statement of facility and observation fees and the health plans they are in network with, or a statement that they are out of network. They may not advertise that they “take” or “accept” a plan unless they are in network.
• Out-of-network emergency claims. Patients cannot be balance billed for emergency care. Payment disputes with state-regulated plans go through Texas arbitration, and disputes with federally regulated plans go through federal IDR under the No Surprises Act. See our guide to federal vs Texas IDR.
• Medicaid managed care leveling. Superior HealthPlan and Community Health Choice now review freestanding ER level 4 and 5 claims, so the same coding standards apply as for hospital EDs.

For freestanding ERs, ER billing compliance and payment recovery are closely tied: an underpaid out-of-network claim can only be recovered through IDR if the original claim was coded and documented correctly. Learn more about our freestanding ER billing in Texas and Texas IDR services.

Documentation That Supports the Level You Bill

Good ED documentation answers the questions an auditor or payer reviewer will ask. For a level 4 or 5 professional visit, the note should show:

1. The presenting problem and why it was a threat to life or bodily function, when that is the case.
2. The differential diagnosis the provider considered and ruled out.
3. Every test ordered or reviewed, independent interpretation of images or EKGs, and history obtained from others such as EMS or family.
4. Management decisions and their risk, such as admission, prescription drugs, parenteral controlled substances or a decision not to admit.
5. Reassessments and the patient’s response to treatment.
6. For critical care: total critical care time, excluding separately billed procedures, and the organ failure or threat being treated.

Key takeaway: A claim is only as strong as the codes on it. ER billing compliance in 2026 means the chart must support the level, and the claim must carry every diagnosis and workup code that proves it.

ER Billing Compliance Checklist

Check	Why it matters
Written facility leveling policy, reviewed yearly	Required basis for facility levels and your first defense in an audit
All labs, imaging and EKGs on the facility claim	Payer leveling tools set the level from these codes
Comorbidities and external cause codes captured	Raises calculated complexity and supports medical necessity
Modifier 25 only with a separate, documented E/M	Current OIG audit focus
Critical care time documented, ED visit before critical care	Long-standing Recovery Audit topic
Modifier FS on split/shared visits	Required by Medicare for physician and APP visits
POS 23 and revenue code 045X on ED claims	OIG found millions paid for ED codes in the wrong setting
Monthly audit of level 4 and 5 rates by provider	Spots outliers before a payer or auditor does
Texas FSER disclosures signed and stored for one year	Required by Texas law

How to Respond to a Downcoded ED Claim

1. Read the remittance and confirm whether the payer changed the level, denied the line or asked for records.
2. Check the exclusions. Admissions, transfers, critical care, patients under 2 and deaths in the ED are excluded from most leveling policies.
3. If codes were missing, send a corrected claim with every diagnosis and workup code.
4. If the claim was complete, request reconsideration with the full ED record and a short letter that ties the documentation to your leveling criteria.
5. Track every downcode by payer and reason. Repeated reductions on correct claims are evidence for contract talks and, for out-of-network claims, for IDR.

Our denial management services team handles this for ERs and freestanding EDs. You can also check whether an underpaid out-of-network claim qualifies for dispute with our free IDR Claim Checker.

How ZanexMed Helps Hospital and Freestanding ERs

ZanexMed works with hospital EDs and freestanding ERs across Texas on coding, claims, denials and out-of-network recovery. We audit level 4 and 5 visits before billing, make sure every diagnosis and workup code reaches the claim, fight downcodes with documented appeals and take underpaid out-of-network ER claims through Texas or federal IDR. See our medical coding services and billing audit services, or request a free billing audit.

ER Billing Compliance FAQs

Sources

• UnitedHealthcare, Emergency Department Facility E/M Coding Policy (2026R6003A)
• Superior HealthPlan, CC.PP.064 Emergency Department E/M Leveling
• Community Health Choice, ED Facility E/M Leveling Policy (effective October 18, 2026)
• HHS OIG, A-07-23-05139: ED procedure codes billed with non-ED sites of service (March 2026)
• CMS, Approved RAC topic 0070: Critical care billed the same day as ER services
• Texas Legislature, HB 2041 bill analysis (freestanding ER disclosures)
• HealthLeaders, Cigna E/M downcoding policy
• CMS, No Surprises Act

This guide is for general billing education and reflects rules and payer policies in effect on November 4, 2026. It is not legal advice. Confirm payer contract terms before submitting claims.