Common Medical Billing Errors

Duplicate charges are the most straightforward billing error and among the most common. They occur when the same service, medication, or supply is billed twice for the same date of service.

Duplicates happen for mundane reasons: a nurse records a medication at bedside, and the pharmacy system independently logs the same dose. A lab test is ordered by your ER doctor, and the admitting physician re-orders it without realizing. A charge is entered manually after a system migration and the original record is also retained.

To spot duplicates, review your itemized bill for identical billing codes on the same date. Not all duplicates are obvious — sometimes the same service appears under different descriptions or revenue codes. If two charges seem to describe the same thing, ask the billing department to verify that both represent distinct services.

Duplicates are the easiest errors to get corrected because they're objectively verifiable. A simple call pointing out that CPT 85025 (complete blood count) appears twice on the same date usually results in immediate removal of the duplicate.

Upcoding occurs when a provider bills for a higher-level (more expensive) service than what was actually performed. This is one of the costlier errors because the price difference between coding levels can be hundreds or thousands of dollars.

The most common upcoding involves evaluation and management (E/M) codes:

• —Level 3 ER visit (CPT 99283): ~$800
• —Level 4 ER visit (CPT 99284): ~$1,500
• —Level 5 ER visit (CPT 99285): ~$2,500+

If you went to the ER for a straightforward issue — a minor laceration, a sprained ankle, a simple infection — and your bill shows a level 4 or 5 visit code, it may be upcoded. The coding level should reflect the complexity of medical decision-making, the amount of data reviewed, and the number of problems addressed.

Upcoding is harder to dispute than duplicates because it involves clinical judgment. However, if the code description clearly doesn't match your experience, request a coding review from the billing department. Hospitals are required to have processes for reviewing coding accuracy upon patient request.

Unbundling is the practice of billing individual components of a service separately instead of using the correct bundled code. The sum of unbundled charges is always higher than the single bundled rate.

Common unbundling examples:

• —A comprehensive metabolic panel (CPT 80053) covers 14 tests for roughly $50-$150. Unbundled as 14 individual tests, the total can exceed $500.
• —A surgical package typically includes the procedure, local anesthesia, and standard post-operative care. Unbundled, each component generates a separate charge.
• —Imaging studies with multiple views may be unbundled into separate charges per view rather than billed as a single multi-view study.

The Centers for Medicare & Medicaid Services (CMS) publishes National Correct Coding Initiative (NCCI) edits — rules that define which codes should not be billed together because one includes the other. While these rules technically apply to Medicare claims, they represent the industry standard for proper coding.

To spot unbundling, look for clusters of related charges on the same date. If you see five or six lab charges that seem like they should be one panel, or surgical charges that seem like they should be part of one procedure, ask the billing department whether a bundled code applies.

Billing errors caused by incorrect patient information are more common than most people realize. A wrong date of birth, a misspelled name, or an incorrect insurance ID number can cascade into denied claims, incorrect charges, or even charges from another patient appearing on your bill.

Common patient information errors include:

• —Incorrect insurance details — leading to claims being denied and billed to you at self-pay rates instead of at your insured rate
• —Wrong date of service — charges appearing on the wrong day, which can affect insurance coverage and deductible calculations
• —Patient mix-ups — in busy hospital settings, charges intended for another patient with a similar name can end up on your account
• —Incorrect diagnosis codes — the wrong ICD-10 diagnosis code can cause insurance denials even if the procedure code is correct

Always verify the basic information at the top of your bill: your name, date of birth, date of service, and insurance information. If anything is wrong, it could mean some or all of the charges are incorrect. Contact the billing department immediately to correct patient information errors — they often resolve insurance denials and reduce your balance automatically.

Being billed for services you never received is a clear-cut error, but it happens more often than you'd expect. In complex hospital stays involving multiple departments and providers, charges can be generated for procedures that were ordered but cancelled, tests that were planned but never performed, or services intended for a different patient.

Common scenarios:

• —A test or procedure was ordered but not performed because your condition changed or you were discharged before it happened
• —A specialist consultation was scheduled but never occurred — yet the consult charge was generated when the order was placed
• —Supplies were issued from the pharmacy or supply chain but returned unused — the charge was recorded at issue but the return credit was missed

Review your bill against your discharge summary and any records of what actually happened during your visit. If you see a charge for a procedure you don't remember receiving, ask the billing department to verify it against the clinical record. You have the right to request proof that a billed service was actually provided.

This type of error accounts for a significant portion of the 80% of bills estimated to contain mistakes ². It's also one of the easiest to resolve once identified, since the hospital's own records will confirm whether the service occurred.

Errors in quantity and dosage billing are particularly common with medications and supplies. Being charged for 10 doses of a medication when you received 3, or being billed for the 500mg tablet when you received the 250mg, can significantly inflate your bill.

These errors arise from several sources:

• —Pharmacy dispensing records may show the full quantity dispensed to the floor, not the amount actually administered to you
• —Unit-of-measure confusion — a medication might be dispensed in vials but billed per milligram, or dispensed in packs but billed per individual unit
• —Supply kits may be billed as complete kits even when only a few items from the kit were used
• —Rounding up on time-based charges — a 45-minute procedure billed as two full hours of OR time

To catch these errors, look at medication and supply charges carefully. If you were in the hospital for one day, a charge showing 7 days of a medication is obviously wrong. For surgical supplies, charges for multiple units of high-cost items should be verified. If something looks off, ask the billing department to reconcile the billed quantities against the clinical administration records.

Even small quantity errors add up. An extra $20 charge across five medications is $100 — and hospitals process millions of these transactions, so systemic rounding errors are profitable to maintain.

Catching billing errors requires a methodical approach. Here's a step-by-step process that covers the most common issues.

Step 1: Get your itemized bill. Call the billing department and request a fully itemized statement with billing codes, descriptions, dates, and amounts for every charge.

Step 2: Verify patient information. Confirm your name, date of birth, date of service, and insurance details are correct at the top of the bill.

Step 3: Cross-reference with your EOB. If you have insurance, compare every line item against your Explanation of Benefits. Look for discrepancies in amounts, services, and patient responsibility.

Step 4: Scan for duplicates. Sort or review charges by date, looking for identical or near-identical billing codes on the same day.

Step 5: Check for unbundling. Look for clusters of related charges that might be components of a single bundled procedure.

Step 6: Verify services rendered. Compare each charge against your memory of the visit and any discharge paperwork. Flag anything you don't recognize.

Step 7: Compare against market rates. Upload your bill to compare each billing code against what other facilities in your area charge. Charges significantly above the local median deserve scrutiny.

Step 8: Document and dispute. For every error you find, note the specific charge, billing code, amount, and the nature of the error. Then contact the billing department — by phone first, then in writing.