Common Medical Billing Errors: How to Spot and Fix Bill Mistakes
You go to the doctor, get treated, and weeks later a bill arrives. You glance at the total and pay it. Sound familiar? If so, you might be paying too much.
Here's a startling fact: Studies show that more than half of all medical bills contain errors. One patient advocate estimates she finds errors on 9 out of every 10 hospital bills she reviews [citation:5][citation:9]. Whether these mistakes are accidental or intentional, they cost patients billions of dollars every year [citation:9].
In 30 Seconds
- 💸 Billing errors are common – More than 50% of bills have mistakes
- 🔍 You can catch them – Most errors are easy to spot if you know what to look for
- 💪 Don't pay without reviewing – Always check your bill before you pay
- 📋 Keep records – Document everything when you dispute a charge
This guide walks you through the most common medical billing errors—and exactly what to do when you find one.
1. Why Do Medical Billing Errors Happen?
Medical billing is incredibly complex. With more than 70,000 billing codes representing various treatments and procedures, there's plenty of room for mistakes [citation:5]. Here's why errors are so common:
- Complex coding systems – ICD-10, CPT, and HCPCS codes are constantly updated, making it hard to keep up [citation:7]
- Fragmented systems – Different providers (hospitals, labs, physicians) often bill separately and don't communicate well [citation:2]
- Human error – Simple mistakes like typos, wrong dates, or incorrect patient information are frequent [citation:4]
- Lack of transparency – Patients rarely see itemized bills unless they specifically ask [citation:5]
- Systemic complexity – Medicare alone operated over 30 payment programs in 2024, and billing rules vary widely [citation:2]
"The disconnect between what's billed, what's documented, and what's actually true has deepened." [citation:2]
The result? Patients are left to untangle errors, advocate for themselves, and navigate conflicting information—often while dealing with serious health issues [citation:5].
2. The Most Common Medical Billing Errors
Here are the most frequent billing errors you need to watch for. Each one can cost you hundreds or thousands of dollars [citation:9].
Upcoding
Example: Billed for 60-minute session, only had 15What it is: Billing for a more expensive service than what was actually performed. This can be accidental or intentional—and can lead to fraud investigations [citation:1][citation:4].
✅ Fix: Compare the service description to what you actually received. Ask for the code and its definition.Unbundling
Example: Billing a surgery prep, anesthesia, and recovery separatelyWhat it is: Billing multiple CPT codes for components of a procedure that should be covered by a single comprehensive code [citation:1][citation:7].
✅ Fix: Ask if the services should be billed under one code. This is often a red flag for overcharging.Duplicate Billing
Example: Same service billed twice on one visitWhat it is: Being charged multiple times for the same service. This is especially common when multiple providers are involved in your care [citation:3][citation:9].
✅ Fix: Review every line item carefully. If you see the same service twice, call the billing office immediately.Wrong Billing Code
Example: Code for a specialist visit when you saw a nurseWhat it is: Using an incorrect CPT, HCPCS, or ICD-10 code. Even one wrong digit can lead to claim denials or overcharges [citation:4][citation:7].
✅ Fix: Look up each code online and verify the description matches your care. Ask the provider to correct and resubmit.Incorrect Patient Information
Example: Misspelled name or wrong birthdateWhat it is: Simple errors like a misspelled name, wrong date of birth, or outdated insurance ID. These can lead to claim denials [citation:4][citation:9].
✅ Fix: Confirm your name, DOB, and insurance details are correct on every bill.Charges for Services You Never Received
Example: Test ordered but canceled—still on your billWhat it is: Billing for tests, procedures, or medications that were ordered but never actually provided [citation:5][citation:9].
✅ Fix: Request your medical records and compare them to the bill. If it's not documented, it shouldn't be billed.Separate Charges for Included Items
Example: Charging extra for gloves or surgical gownsWhat it is: Billing separately for supplies or services that should already be included in the base cost of a procedure [citation:9].
✅ Fix: Ask if each supply or service is essential and already included in the procedure cost.Mismatched Diagnosis and Procedure Codes
Example: Knee X-ray for a routine physical with no knee complaintWhat it is: The diagnosis code (ICD-10) doesn't justify the procedure code (CPT). This usually leads to claim denials [citation:7].
✅ Fix: Verify the diagnosis supports the treatment. Ask the provider to explain the connection.⚠️ Don't Pay Until You Review
Before paying any bill, run through this quick checklist:
3. Real-World Examples of Billing Errors
These true stories show how common—and costly—billing errors can be:
Patient Story 1 Medical Bill for the Wrong Person: Doug Smith received a $472 bill for blood work at a hospital he'd never visited. He was insured by a company he no longer had coverage with. It turned out a doctor with offices at two different hospitals had ordered blood work for Smith—and the wrong hospital billed him. It took filing a complaint with the state attorney general to resolve [citation:5].
Patient Story 2 Wrong Code Made Life-Saving Surgery Look "Elective": A man recovering from heart surgery discovered his insurance denied coverage because a single incorrect code made his emergency surgery appear "elective." The error cascaded through the system, triggering payment denials and appeals—all because of one entry that went unchecked [citation:2].
Patient Story 3 Cancer Patient Fights $30,000 in Billing Errors: Mary Katherine Snow, a leukemia patient, received $30,000 in bills when her care was mistakenly billed as out-of-network. Over four years, she spent hours on the phone, saw her credit score drop 140 points, and was sent to collections—all while fighting cancer. "I've spent so many hours trying to fix these mistakes. It's like a second job," she said [citation:5].
4. Step-by-Step: How to Spot Errors
Follow these steps to catch billing mistakes before you pay [citation:3][citation:9]:
Your 7-Step Error Check
- Request an itemized bill. Many providers send a summary with just a total. Ask for a detailed list of every charge.
- Check the basics. Confirm your name, date of birth, provider name, and service dates are correct [citation:4][citation:9].
- Compare to your medical records. You shouldn't be billed for anything that isn't documented in your records [citation:3].
- Look up each billing code. Type the code with "medical billing code" into a search engine and read the description. Does it match your care? [citation:3]
- Check for duplicate charges. Look for the same service listed twice [citation:3][citation:9].
- Compare to your EOB. Your Explanation of Benefits from your insurance company should match your bill. If the "patient responsibility" amounts don't match, investigate [citation:3][citation:9].
- Verify quantities. If you were charged for multiple units (e.g., 10 hours in surgery), make sure the number is correct [citation:9].
Pro tip: If you were in the hospital, ask a family member or friend to keep track of who sees you. Patients sometimes receive bills from doctors they've never met [citation:9].
Learn more: How to Read a Medical Bill and How to Read an Explanation of Benefits (EOB).
5. What to Do If You Find an Error
If something on your bill doesn't look right, speak up. Studies show that 74% of people who contact their provider or insurer about a billing error are able to get it corrected [citation:9].
Follow this action plan:
Action Plan
- Gather the facts. Have your itemized bill, EOB, and medical records ready.
- Call the provider's billing office. Ask them to walk you through every charge. If a code seems wrong, ask them to verify and correct it [citation:5].
- Keep detailed records. Write down the name of everyone you speak with, the date and time, and what was said. Ask for written confirmation of any resolution [citation:9].
- If the provider doesn't help, call your insurance company. They may be able to resolve the issue with the provider directly [citation:3].
- Be persistent. It takes patient advocates an average of 25 to 32 calls to resolve a billing case. Don't give up [citation:5][citation:9].
- If you're still stuck, escalate. File a complaint with your state's insurance commissioner, contact a patient advocate, or seek help from a Consumer Assistance Program [citation:3][citation:9].
Need more help? How to Dispute a Medical Bill
Key Reminders
- Don't pay a bill you're disputing – but don't ignore it either. Keep the provider informed [citation:9].
- Watch for deadlines. You typically have 180 days to appeal a claim with your insurer [citation:12].
- You have rights. The No Surprises Act protects you from certain out-of-network bills [citation:9].
6. How to Prevent Future Billing Errors
The best way to deal with billing errors is to prevent them before they happen. Here's what you can do:
Related: How to Lower a Medical Bill and Hospital Financial Assistance Guide.
Frequently Asked Questions
How common are medical billing errors?
Studies show that more than half of all medical bills contain errors. One patient advocate estimates she finds errors on 9 out of every 10 hospital bills she reviews [citation:5][citation:9]. A 2024 survey found that 43% of adults said they've received a medical or dental bill they believed was erroneous [citation:11].
What is upcoding in medical billing?
Upcoding happens when a provider bills for a more expensive service than what was actually performed [citation:1]. For example, billing for a 60-minute therapy session when only 15 minutes were provided. Upcoding can be accidental or intentional—and can lead to fraud investigations [citation:4].
What should I do if I find an error on my medical bill?
Call your provider's billing office and explain the error. Keep detailed records of who you spoke with and what was said. If needed, contact your insurance company and consider filing a formal dispute. 74% of people who speak up are able to get the mistake corrected [citation:9].
Next step: What to Do If You Find an Error
What is unbundling in medical billing?
Unbundling occurs when a provider bills multiple CPT codes for components of a procedure that should be billed under a single comprehensive code [citation:1][citation:7]. This can lead to overcharging and compliance issues. For example, billing separately for the prep, anesthesia, and recovery of a single surgery [citation:1].
How can I check if my medical bill has errors?
Request an itemized bill, compare it to your medical records and Explanation of Benefits (EOB), look up billing codes online, check for duplicate charges, and verify you actually received every service listed [citation:3][citation:9].
Related: Step-by-Step: How to Spot Errors
Can I be sent to collections while disputing a bill?
Yes—it happens more often than it should. Patients have been sent to collections even while they were actively disputing a bill [citation:5]. If this happens, document everything, continue disputing the charge, and consider filing a complaint with your state's insurance commissioner or attorney general.
Final Takeaway
Medical billing errors are incredibly common—but you don't have to be a victim. By taking a few minutes to review your bills, you can catch mistakes before you overpay. The key is to always request an itemized bill, compare it to your EOB and medical records, and speak up if something looks wrong.
Your final task today: Pull out your most recent medical bill. Run through the 7-step error check above. If you find an error, call the billing office and start the dispute process. You could save hundreds—or even thousands—of dollars.
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