The 5 Billing Mistakes Hospitals Make Most Often at the End of the Year

Every year, from Thanksgiving through New Year’s, hospital billing systems get messy. Staffing changes, higher patient volume, and insurance plan resets create the perfect storm for errors. These mistakes are not small. They can turn a simple visit into a bill that makes your stomach drop.

If you get a hospital bill in December or January, you need to look at it with fresh eyes. I want to walk you through the five most common mistakes hospitals make at the end of the year and what to do about each one.

This is not about blaming staff. Most hospitals are overwhelmed. But the mistakes are real, and they end up in your mailbox.

1. Incorrect insurance information

Insurance plans change January 1. People switch employers. Deductibles reset. ID numbers change. Hospitals know this, but registration teams are often rushed. A small error in the insurance field is enough to cause:

• A rejected claim
• A full balance billed to you
• A “patient responsibility” charge that should be zero

What to do: Call your insurance company and ask if the hospital billed the claim correctly. Have them read the submitted information back to you. If anything is wrong, ask them to send the correction electronically and tell the hospital to reprocess.

Small fix. Big savings.

2. Wrong provider or facility coding

This is one of the most common billing issues I see in December. A visit that should be billed as urgent care gets coded as an emergency department visit. A simple treatment gets billed with a complex-level code. Facility fees get added where they should not be.

These errors can raise your bill by hundreds or thousands.

What to do: Request your itemized bill. Look for:

• CPT codes you do not recognize
• ED facility fees for simple problems
• Charges for services you never received

If something looks wrong, ask the hospital to audit the claim. They are required to review it.

3. Duplicate charges

Holiday periods often involve multiple handoffs. That is where duplicate charges sneak in. You might see:

• Two lab draws
• Two imaging studies
• Multiple supply charges
• Repeat injections

The only way to spot duplicates is through the itemized bill. Hospitals do not send this unless you ask.

What to do: Circle each duplicate. Ask the billing office to remove every repeated charge and reprocess the claim with your insurer.

4. Out-of-network providers inside an in-network hospital

This problem peaks during holidays because hospitals use more contract providers to fill staffing gaps. Even if the hospital is in network, the physician in the room may not be.

The result is a surprise bill that you did not consent to and did not expect.

What to do: Under federal law, you have protections if this was an emergency or if you had no ability to choose an in network provider. Tell the hospital you are disputing the charges under the No Surprises Act and ask for a corrected bill.

Most people do not realize this is an option. It is.

5. Charges tied to services that did not happen

This one is simple. December is chaotic. Mistakes happen. Sometimes a charge gets added to your record by accident. Maybe the test was started but not completed. Maybe the order was placed but canceled. Maybe the clinician clicked the wrong box.

What to do: Compare your bill to what actually happened in the ER or clinic. If a provider ordered something but never delivered it, challenge it.

“Please remove any charges for services that were not performed.”
That is all you need to say.

Bonus: You may qualify for financial assistance even if you think you do not

Most hospitals offer discounts at 300 to 400 percent of the Federal Poverty Level. Many people think they are over the threshold. They are not.

The end of the year is the perfect time to apply because financial assistance looks at your full-year income. If you had months with reduced hours, job changes, or temporary hardship, it can improve your eligibility.

What to do: Ask for the financial assistance application. Fill it out. Submit pay stubs, bank statements, or any proof of income.
There is no downside to applying.

Why this matters

Bills that arrive in December or January carry more mistakes than any other time of year. You are not imagining it. You are not overreacting. You are responding to a system that is stretched thin.

This is why I wrote Hospital Bill Survival Guide. Not to make anyone an expert in medical billing, but to give people the tools that should have been provided to them from the start. No one should feel alone or embarrassed when a bill shows up. You can understand it. You can question it. You can fix it.

You deserve clarity and fairness, even in the most chaotic month of the year.