12 common medical billing errors and how to spot them
Updated September 30, 2026 · How we write our guides
Quick answer
Common medical billing errors include duplicate charges, services you didn't get, wrong quantities, a visit billed at a higher level than your records show, and discounts or payments that weren't applied. To find them, compare an itemized bill with your explanation of benefits (EOB) and your own records, 1 line at a time.
Key takeaways
- Check an itemized bill, not just the total, against your explanation of benefits (EOB).
- Some errors are quick fixes, like a wrong ID number, a doubled line, or a payment that wasn't posted.
- Coding questions, like visit levels or services split into parts, are fair to ask about.
- Ask for a corrected bill, and ask the provider to hold your account while it checks.
Mistakes happen on medical bills, and some of them cost you money. This checklist covers 12 common medical billing errors, how to spot each one, and what to do. It's part of our guide on how to lower medical bills.
You don't need to know billing codes to use it. You need an itemized bill, your explanation of benefits (EOB), and your own notes about the visit.
How to find errors on a medical bill
- Get an itemized bill. It lists every charge, 1 line at a time. See how to get an itemized bill.
- Find your EOB. Your insurer mails it or posts it online. Our guide to the EOB vs. medical bill shows how to line them up.
- Gather your own records. Your visit summary, discharge papers, receipts, and notes all help.
- Go through the checklist below. Circle any line you can't explain.
You can also print our medical bill checklist.
The checklist
- Your name, birth date, and insurance ID are right
- No charge appears twice
- You got every service listed
- Quantities and units make sense
- Each visit is billed at the level your records show
- Services that go together aren't billed in parts
- An in-network provider isn't billing more than your EOB share
- Your insurer's discount was applied
- Every payment you made is credited
- Preventive care isn't billed as diagnostic
- The dates of service are right
- The claim reached your insurer, and any denial has a real reason
The 12 errors and what to do about each
1. Wrong patient or insurance details
How to spot it: Check your name, birth date, and insurance ID on the bill and the EOB. A single wrong digit can lead your insurer to deny the claim. The EOB may say the ID and name don't match.
What to do: Call the billing office with your insurance card in hand. Ask them to fix your details and send the claim again.
2. Duplicate charges
How to spot it: Look for 2 lines with the same code, date, quantity, and price. Some repeats are correct, like a drug given twice or a room charge for each day.
What to do: Ask the billing office to check your medical record and remove any true duplicate. See duplicate charges on a medical bill.
3. Services you didn't get
How to spot it: Ask yourself if each line happened. Watch for tests that were canceled, or supplies and drugs you didn't use.
What to do: Ask the provider to check your medical record. If the record doesn't show the service, ask them to take it off.
4. Wrong quantities or units
How to spot it: Check the quantity column. A drug billed as 10 units when you got 1 shot is worth asking about.
What to do: Ask what each unit means. Some drugs are billed in small units, so a high number can be right.
5. A visit billed at a higher level than your records show
How to spot it: Visits are billed at levels, from simple to complex. The level reflects how complex your care was, or for office visits, the time spent. A quick visit for a minor problem billed as a complex one is worth a question. The industry term for this is upcoding, and it can happen by mistake.
What to do: Ask the provider to review your records and explain why they chose that level. Keep it a question, not an accusation.
6. Unbundling
How to spot it: Some groups of services are meant to be billed under 1 code. Unbundling means billing the parts separately, which usually costs more. Medicare and Medicaid coding rules list pairs of codes that generally shouldn't be billed together on the same day. It's hard to spot, but many small lines tied to 1 procedure are a clue.
What to do: Ask the billing office whether those lines should have been billed together. Check your EOB too. If it says a line's payment is included in another service, ask why that line is on your bill.
7. Balance billing by an in-network provider
How to spot it: Compare the amount due with your share on the EOB. For covered services, an in-network provider generally can't bill you more than that. Billing you for more is called balance billing.
What to do: Ask the provider to bill you only your EOB share. If an out-of-network doctor treated you in an emergency or at an in-network hospital, federal law may protect you too. See does the No Surprises Act apply to my bill.
8. Your insurer's discount wasn't applied
How to spot it: In-network providers agree to a set price for each service, called the allowed amount. Your bill should show the difference as an insurance or contractual adjustment. If that's missing, you may be billed the full price.
What to do: Send the billing office a copy of your EOB. Ask them to post the adjustment and send a new bill.
9. A payment wasn't credited
How to spot it: Look for your copay, deposit, and any earlier payments on the bill. Your insurer's payment should show up too.
What to do: Send a copy of your receipt or bank statement and ask them to credit it. If you paid more than you owed, ask for a medical bill refund.
10. Preventive care billed as diagnostic
How to spot it: Most plans must cover certain screenings and shots at no cost from an in-network provider. If a routine checkup or screening shows a copay or deductible, it may have been coded as diagnostic. But if the provider also treated a new problem or did extra tests, you may owe for that part.
What to do: Ask the provider how the visit was coded. If it was a routine screening, ask them to fix the code and resend the claim. See preventive care billed as diagnostic.
11. Wrong date of service
How to spot it: Check each date against your calendar or visit summary. A wrong date can make a claim look like a duplicate. It can also place care outside the dates your coverage was active.
What to do: Ask the provider to correct the date and resend the claim.
12. The claim wasn't sent, or was denied for a fixable reason
How to spot it: If there's no EOB for a bill, your insurer may never have gotten the claim. If the EOB shows a denial, look at the code. Code 16 means information was missing or there was a billing error. Code 22 means another plan may need to pay first.
What to do: Ask the provider to bill your insurer, or to fix the claim and send it again. Our letter asking a provider to bill insurance first puts it in writing. If you have 2 plans, see coordination of benefits. If you have Original Medicare, the law requires providers to file your claims for covered care.
How to correct a medical billing error
- Call the billing office. Give your account number, point to the line, and say what looks wrong. Write down the date, the person's name, and what they said.
- Ask for a hold. Ask them to hold your account while they check, so it doesn't go to collections.
- Call your insurer if the claim is involved. Ask it to reprocess the claim once the provider sends a corrected one.
- Put it in writing if a call doesn't work. See how to dispute a medical bill and our medical bill dispute letter.
- Check the new bill before you pay. Compare it with the new EOB, if there is one.
When to get help
You can fix many errors with a call or 2 and a letter. It's worth getting help when:
- The provider won't explain a code or fix a clear error.
- Your insurer denied the claim, and you're not sure why.
- The bill is already in collections.
- You're checking bills for someone else and you're short on time.
Your insurer's member services team can explain a claim. The number is on your insurance card. For surprise out-of-network bills, call the No Surprises Help Desk at 1-800-985-3059. A medical bill advocate can make the calls for you.
Common questions
How do I find errors on my medical bill?
Ask for an itemized bill that lists every charge. Find the explanation of benefits (EOB) from your insurer for the same visit. Then compare them line by line, along with your notes, receipts, and visit summary. Look for repeats, services you didn't get, odd quantities, and missing payments or discounts. Circle anything you can't explain and ask about it.
Who should I call about a billing error, the provider or my insurer?
Start with the provider's billing office for errors on the bill itself, like a doubled line or a payment that wasn't credited. Call your insurer about how the claim was processed, like a denial or a missing discount. If you're not sure, call both. Each one can often tell you what the other needs to fix it.
Should I pay a medical bill while I question an error?
Ask the billing office to put your account on hold while they review it, and write down who agreed to the hold. Pay any part you agree you owe, so that part doesn't go late. It's usually easier to fix a bill before you pay it than to get a refund later. Keep notes of every call.
Can a provider fix a billing error after I've paid?
Yes, and you can ask them to. Request a corrected bill and a refund of anything you paid that you didn't owe. Put it in writing with copies of the bill, your EOB, and your receipt. If your insurer needs to reprocess the claim, ask the provider to send a corrected claim. Then check the new EOB before you accept the refund amount.
What if the provider won't correct the error?
Put your request in writing and keep a copy. Ask for a supervisor or the hospital's patient advocate. If the problem is how your insurer processed the claim, you can file an appeal. For surprise out-of-network bills, the No Surprises Help Desk takes complaints at 1-800-985-3059. Your state insurance department or attorney general's consumer office may also help.
Check your bill before you pay
A printable list of what to look for on any medical bill, with a link to help for each item.
Sources
- Reading your explanation of benefits (EOB), Centers for Medicare & Medicaid Services. Accessed September 30, 2026.
- Claim adjustment reason codes, X12. Accessed September 30, 2026.
- Balance billing (glossary), HealthCare.gov. Accessed September 30, 2026.
- What is the Medicaid NCCI? (How to use the Medicaid National Correct Coding Initiative tools), Centers for Medicare & Medicaid Services. Accessed September 30, 2026.
- Evaluation and management services (MLN006764), Centers for Medicare & Medicaid Services. Accessed September 30, 2026.
- Preventive health services, HealthCare.gov. Accessed September 30, 2026.
- Yearly "Wellness" visits, Medicare.gov. Accessed September 30, 2026.
- Filing a claim, Medicare.gov. Accessed September 30, 2026.
Keep going
- Start hereHow to lower your medical bills: the complete guideLower a medical bill in the right order: check for errors, fix insurance problems, then ask for charity care, discounts, and an interest-free payment plan.
- Related guideInsurance didn't pay my medical bill: what to do nextInsurance didn't pay your medical bill? Find out why, match the denial code to the fix, and learn when to ask for a rebill and when to file an appeal.
- Next stepHow to dispute a medical bill: steps and letter templateThink your medical bill is wrong? Here's how to dispute it: what to check, what to say, what to put in a letter, and where to turn if you're stuck.
This is general information, not legal or medical advice. Rules can depend on your plan and your state. Romi Care isn't an insurer, law firm, collection agency, or government program.