Common ER Bill Errors and How to Catch Them

The average emergency room visit in the United States costs roughly $2,200, according to data from the Health Care Cost Institute. For visits that require imaging, lab work, or procedures, that number climbs fast -- bills of $5,000 to $15,000 are not unusual. And ER bills are among the most error-prone in all of medical billing.

The reason is structural. When you go to the ER, you may be treated by an emergency physician, a radiologist, an anesthesiologist, a lab technician, and a nurse -- each of whom may bill separately, often through different billing companies. The hospital itself sends a separate facility charge. This fragmentation creates dozens of opportunities for errors, duplicates, and overcharges that patients rarely catch because they are overwhelmed, in pain, or simply unaware of how the billing works.

This guide covers the seven most common ER billing errors, how to spot them on your itemized bill, and what to do about each one.

How ER billing works

Before diving into errors, you need to understand the basic structure. An ER visit typically generates two or more separate bills:

• The facility fee -- charged by the hospital for using the ER space, equipment, supplies, and nursing staff. This is the big one. It is billed using revenue codes (often 0450-0459 for ER services) and usually includes a CPT code for the ER visit level.
• The physician fee -- charged by the emergency medicine doctor who treated you. This is a separate professional service bill, coded with E/M codes 99281 through 99285 depending on the complexity of your visit.
• Ancillary bills -- separate charges from radiologists (for reading X-rays or CTs), pathologists (for lab interpretation), anesthesiologists (if sedation was used), and any specialists who were consulted.

Each of these bills is legitimate in concept. The problem is that errors compound across them. A duplicate charge on the facility bill, an upcoded physician fee, and an out-of-network radiologist you never chose can collectively add $1,000 or more to your total cost.

Facility fee vs. physician fee double billing

This is one of the most common and most confusing ER billing errors. It happens when the same service appears on both the facility bill and the physician bill in a way that results in you paying twice for the same thing.

Here is how it works. The hospital charges a facility fee that includes ER nursing care, monitoring equipment, and basic supplies. The physician charges a professional fee for their evaluation and management of your case. Both charges are legitimate -- but the line items should not overlap.

What to look for:

• The same CPT code (e.g., 99284) appearing on both the facility bill and the physician bill without appropriate modifiers. The facility bill should carry a different revenue code structure.
• Supplies like IV starts, wound care kits, or splints charged on the facility bill when they are already bundled into the physician's E/M code for the same service.
• Nursing assessments or triage evaluations billed as separate line items when they are part of the facility fee.

Request both your hospital facility bill and your physician bill. Compare them side by side. If you see identical descriptions or CPT codes on both bills for the same date, one of them is likely a duplicate.

ER level upcoding (99281-99285)

Emergency department visits are coded on a five-level scale from 99281 (minor, self-limited problem) to 99285 (high severity, life-threatening). Each level carries a significantly different price:

• 99281 -- Minor problem, straightforward decision-making. Medicare rate: approximately $30-50.
• 99282 -- Low to moderate severity. Medicare rate: approximately $50-80.
• 99283 -- Moderate severity. Medicare rate: approximately $95-130.
• 99284 -- High severity, urgent evaluation required. Medicare rate: approximately $145-200.
• 99285 -- High severity with immediate significant threat to life or function. Medicare rate: approximately $215-280.

Upcoding means billing at a higher level than the clinical situation warranted. A patient who comes in with a sprained ankle and gets an X-ray and an ACE bandage should be coded at 99282 or 99283. If the bill says 99285, that is upcoding. The difference between a level 3 and level 5 ER visit can be $150-$250 or more just for the physician fee -- and the facility fee scales similarly.

How to spot it:

• Compare the ER visit level code on your bill to what actually happened during your visit. Were you on a cardiac monitor? Did you receive IV medications? Was a specialist called in? If none of these things happened, a level 4 or 5 code is hard to justify.
• Check if the hospital and physician used different ER levels for the same visit. While they use different criteria, a 99282 from the physician paired with a facility fee equivalent to a level 5 visit is a red flag.
• Look up the CPT code on your bill using our CPT/HCPCS lookup tool to see the Medicare rate and understand what each level requires clinically.

A 2017 study published in JAMA Internal Medicine found that ER upcoding increased significantly over the prior decade, with level 4 and level 5 visits rising from 45% to 59% of all ER claims. Not all of this represents errors -- patients visiting the ER are getting sicker on average -- but it means you should always verify the level on your bill.

Observation vs. inpatient status billing

This is not technically a billing error in the traditional sense, but it is one of the most financially devastating classification decisions in hospital billing. If you are kept in the hospital after an ER visit, your status matters enormously for your bill.

• Observation status -- You are technically an outpatient. The hospital bills outpatient rates, and you pay outpatient copays and coinsurance, which are often higher. Medicare Part B applies, not Part A. Self-administered medications you bring from home may not be covered.
• Inpatient status -- You are formally admitted. The hospital bills under a DRG (diagnosis-related group), and your inpatient benefits apply. For Medicare patients, Part A covers the stay after the deductible.

The critical issue: many patients who spend one, two, or even three nights in the hospital are classified as "observation" and never formally admitted. They assume they were admitted because they were in a hospital bed. They find out the truth when the bill arrives.

What to check:

• Look for revenue codes on your bill. Revenue code 0762 indicates observation services. If you see this code and you spent more than 24 hours in the hospital, ask why you were not converted to inpatient status.
• Under the Medicare Outpatient Observation Notice (MOON) Act, hospitals must notify Medicare patients within 36 hours if they are on observation status. If you are a Medicare beneficiary and were not notified, that is a compliance violation you can report.
• Under the Two-Midnight Rule, if your physician expects you to need hospital care spanning two midnights, you should generally be admitted as an inpatient. If you crossed two midnights on observation status, ask the hospital to review whether your admission status was correct.

Surprise out-of-network ER physicians

You go to an in-network hospital. You assume everyone who treats you is also in-network. They are not. The emergency physician, the radiologist, and the anesthesiologist may all be employed by separate staffing companies that have no contract with your insurer.

Before the No Surprises Act took effect on January 1, 2022, this was one of the most common sources of unexpected medical bills. A 2020 study in the New England Journal of Medicine found that roughly 20% of ER visits at in-network hospitals involved at least one out-of-network physician charge.

What the No Surprises Act changed:

• For emergency services, out-of-network providers cannot bill you more than your in-network cost-sharing amount. Period. This applies to all emergency services, including ancillary services like radiology and anesthesiology provided during the ER visit.
• The provider and your insurer must work out the payment between themselves through an independent dispute resolution (IDR) process. You are held harmless.
• Your insurer must count out-of-network emergency charges toward your in-network deductible and out-of-pocket maximum.

What to look for on your bill:

• Any bill from an ER visit at an in-network hospital where the provider is listed as out-of-network and you are being asked to pay more than your in-network cost-sharing.
• An EOB showing out-of-network benefits applied to emergency services.
• A balance bill (the difference between what the provider charged and what your insurer paid) sent directly to you from an ER provider.

If you receive any of these, you have strong grounds to dispute under the No Surprises Act. See our dispute letter generator to create a letter citing the specific statute.

Balance billing and the No Surprises Act

Balance billing is when a provider bills you for the difference between their charge and what your insurance paid. In the ER context, this was historically devastating -- a provider might charge $3,000, your insurer might pay $800, and you would get a bill for $2,200.

The No Surprises Act (Public Law 116-260, Division BB, Title I) bans balance billing in the following ER situations:

1. All emergency services -- regardless of whether the provider or facility is in-network or out-of-network. This includes the emergency physician, the facility, and all ancillary providers (radiology, pathology, anesthesiology) involved in your emergency care.
2. Post-stabilization services -- services provided after you are stabilized in the ER but before you can be safely transferred or give informed consent to continue care with an out-of-network provider.
3. Air ambulance services -- provided by out-of-network air ambulance providers (note: ground ambulance is not covered by the No Surprises Act).

Your rights under the law:

• You can only be charged your in-network cost-sharing amount (copay, coinsurance, or deductible).
• The provider cannot require you to waive your balance billing protections as a condition of receiving emergency care.
• If you believe you have been balance billed in violation of the No Surprises Act, you can file a complaint with CMS at 1-800-985-3059 or through the CMS No Surprises Help Desk.

If you receive a balance bill for emergency services, do not pay it without first checking whether it violates the No Surprises Act. The law is clear: for emergency care, you owe only your in-network cost-sharing amount.

Unbundling of ER services

Unbundling -- also called fragmentation -- occurs when a provider bills separately for services that should be included in a single bundled code. In the ER, this inflates bills significantly.

Common ER unbundling errors:

• IV access billed separately from IV medication administration. Starting an IV line (36000) is typically bundled into the IV infusion code (96360 or 96365). If both appear on your bill, the IV access charge may be an unbundling error.
• Wound care components billed individually. A simple wound repair (12001-12007) includes local anesthesia, wound exploration, and closure. If you see separate charges for local anesthetic injection (64450) alongside a wound repair code, that is likely unbundled.
• Lab panels broken into individual tests. A comprehensive metabolic panel (80053) includes 14 individual tests. If your bill shows the panel plus individual charges for glucose (82947), sodium (84295), or potassium (84132), those individual tests are already included in the panel and should not be billed separately.
• CT scan with contrast billed as two studies. A CT of the abdomen with contrast (74178) is a single study. Some facilities bill it as a CT without contrast (74150) plus a CT with contrast (74160) to inflate the charge. This is a well-known unbundling scheme.

You can check any two codes from your ER bill for NCCI bundling violations using our free NCCI code pair checker. CMS maintains over 190,000 code-pair edits that define which codes cannot be billed together.

Charges for services not received

It sounds obvious, but it happens constantly: you get billed for services, supplies, or medications that were never actually provided during your ER visit. Studies suggest this occurs on 30-40% of hospital bills.

Common phantom charges in ER bills:

• Medications ordered but never administered. A doctor may order a medication, but the order gets cancelled before the nurse gives it. The charge still posts to your account.
• Supplies charged but not used. Surgical trays, splint materials, or specialty supplies may be charged when they are opened in preparation but ultimately not needed.
• Duplicate imaging. If an X-ray is repeated because the first one was poor quality, you should only be billed for one. Both may appear on your bill.
• Specialist consultations that never happened. A specialist may be paged but never arrive before you are discharged. A consultation charge (99241-99245) may still appear.
• Cardiac monitoring billed for extended hours. If you were in the ER for 3 hours but the bill shows 8 hours of cardiac monitoring (revenue code 0730), the time is wrong.

How to catch phantom charges:

1. Write down everything you can remember about your ER visit as soon as possible -- what tests were done, what medications you received, how long you were there.
2. Request your medical records from the ER visit. The nursing notes and physician documentation will show what was actually ordered and administered.
3. Compare your medical records against your itemized bill line by line. Any charge that does not have a corresponding entry in your medical record is suspect.

How to check your ER bill step by step

1. Request an itemized bill from every provider. You will likely receive multiple bills -- one from the hospital, one from the ER physician group, and possibly separate bills from radiology, pathology, or anesthesiology. Request an itemized statement from each one. You have the right to this under federal law. See our guide on how to read an itemized medical bill for help interpreting each field.
2. Get your EOB from your insurer. Your Explanation of Benefits shows what your insurer approved and what your patient responsibility is. If any provider is billing you more than what the EOB says you owe, that is a red flag.
3. Check the ER visit level. Look for the E/M code (99281-99285) on both the facility and physician bills. Compare it to what actually happened during your visit.
4. Run the math. Add up the individual line items. Does the total match what the bill says you owe? Use our bill math checker to verify.
5. Check for NCCI violations. Pick any two CPT codes from your bill and run them through our NCCI code pair checker. Focus on lab panels, wound care codes, and IV-related charges.
6. Verify your admission status. If you were kept overnight, confirm whether you were classified as observation or inpatient -- and whether that classification was correct.
7. Check for balance billing. If any ER provider is billing you for the difference between their charge and what insurance paid, check whether this violates the No Surprises Act.

What to do when you find an error

1. Document the specific error. Note the CPT code, line item number, date of service, and the amount. Identify the type of error (duplicate, unbundled, upcoded, phantom charge, or balance billing violation).
2. Call the billing department. Start with the billing office for whichever provider sent the bill. Reference the specific line item and explain why you believe it is an error. Many ER billing errors are resolved with a single phone call.
3. Send a written dispute. If the phone call does not resolve it, send a formal dispute letter via certified mail. Our dispute letter generator can create a letter with the correct regulatory citations for your situation.
4. Contact your insurer. If the provider will not correct the bill, call your insurance company's member services number (on the back of your insurance card). Ask them to review the claim. Insurers have audit teams that can flag the same errors you found.
5. File a complaint. For No Surprises Act violations, call 1-800-985-3059 or file through the CMS No Surprises Help Desk. For other billing disputes, file a complaint with your state insurance commissioner.

For more on the dispute process, see our universal dispute guide and our complete guide to medical billing errors. If an ambulance brought you to the ER, check our ambulance billing errors guide for that portion of the bill. For state-specific balance billing protections, see our state rights guide.

Disclaimer: This guide is for educational purposes only and does not constitute legal, financial, or professional advice. Laws and regulations vary by state and situation. The No Surprises Act provisions described here are based on the federal law as of early 2026 -- state laws may provide additional protections. Consult a licensed professional for advice specific to your circumstances.