Gastroenterology billing and coding can be complex due to the specialized nature of presenting problems and coding variation for similar procedures. Even small errors in documentation, ICD-10 diagnosis code, or incomplete or missing reports can result in claim denials, delayed reimbursement, and compliance audits.
Understanding and avoiding common errors can significantly improve claim submission accuracy and ensure proper reimbursement for doctors’ services. Below are 10 of the most frequent mistakes seen in gastroenterology billing and coding, along with tips on how to avoid them.
1. Incorrect Level of Evaluation and Management (E/M) Codes
Even though we might think we have mastered E/M coding, the most frequent audit practices face is for Over or Under coding E/M services. Unscrutinized billing can lead to coding errors.
When was the last time you audited your documentation with the application of your E/M audit sheet?
You might be surprised at how much you will learn about your billing practices just by auditing one exam note per week. One of the most common errors in gastroenterology billing is documenting an incorrect level of E/M code.
How to Avoid
Ensure that all E/M services are documented in detail, including the history, examination, and decision-making processes. Coders should be well-versed with the guidelines for selecting the appropriate level of E/M service. The level of medical decision-making (MDM) will determine the E/M level for most Gastroenterology visits. These can be straightforward, low, moderate, and high.
MDM depends on three elements; two out of these three elements must meet the level of code you will bill. Three elements of MDM are:
- The number and complexity of problems addressed
- Amount or complexity of data to be reviewed, and analyzed
- Risk of complications and/or morbidity or mortality of patient management
Some subcategories must be met for each of these categories. If you need assistance with billing E/M codes, you can always reach out to us for a meeting.
2. Failure to Link Diagnosis Codes Correctly
Every exam, procedure, test, anesthesia service, and lab work must be linked with relevant diagnosis codes to justify the medical necessity. A common error in gastroenterology billing is failing to link covered diagnosis codes to the corresponding services. This can result in denied claims, as payers may deem the service not medically necessary.
How to Avoid
Review your documentation thoroughly to ensure that each service is supported by an appropriate and specific diagnosis code. If you have scribes creating your documentation, be sure to review the entire note before signing and finalizing for billing.
Try to avoid coding unspecified codes. Unspecified codes tend to cause claim rejections. If there is a more specific ICD-10 code that supports the service, always document that code.
3. Incomplete Documentation – Leading Cause of Claim Denials for Procedures
Gastroenterology providers are required to make detailed documentation for procedures, such as colonoscopies, endoscopies, biopsies, video capsules, and other procedures. One of the leading causes of claim denials is incomplete or unsupported documentation for procedures. Missing details, such as the extent of the procedure or additional findings, can lead to coding errors and insurance denials for over-coding or unsupported coding.
How to Avoid
Physicians need to provide detailed documentation of all procedures, including the reason for the procedure, findings, pictures, and documentation of any interventions performed. Diagnosis specificity will give needed support for billed codes and ensure claims are properly reimbursed.
4. Improper Use of Modifier 59
Modifier 59 is used to indicate a procedure or service that was distinct or separate from other services performed on the same day. However, this modifier is often misused, either by applying it when it is not necessary or by failing to use it when appropriate.
Keep in mind Modifier 59 is for unbundling procedures or tests. This modifier cannot be used with E/M codes. Misusing Modifier 59 can trigger audits or claim denials.
How to Avoid
Use Modifier 59 only when the supporting documentation for the procedure is distinct and separate from other services performed on the same day.
For example, biopsies done on separate anatomical locations may require an unbundling modifier. When in doubt, consult current coding guidelines and carefully review your Local Coverage Determination. Build a strong billing and coding team to ensure the accuracy of your billing.
5. Not Following Local Coverage Determinations (LCDs)
Each payer may have their own coverage guideline, referred to as Local Coverage Determination (LCD). Failing to adhere to these guidelines is also one of the common reasons for claim denials, particularly when submitting claims for procedures like diagnostic endoscopies, which may not be covered for certain indications or medical history.
How to Avoid
Familiarize yourself with the LCDs of the major payers your practice is contracted with. Be sure to check for updates, as these guidelines can change. Keep your payer in mind when scheduling patients for procedures.
Guidelines for pre-authorization and referral may vary as well. When in doubt, always call insurance and document the information you receive, and note the call reference number and name of the representative. Submitting claims following LCDs will reduce the likelihood of denials and delays in payments.
6. Bundling Issues
Some procedures, tests, and anesthesia services are considered part of a larger comprehensive service and should not be billed separately. For example, for a colonoscopy, if anesthesia is done by the same provider who is performing the procedure, it is often included in the overall procedure, not billed as a separate service. Failing to bundle appropriately can result in overcharging and audits.
How to Avoid
Review National Correct Coding Initiative (NCCI) edits to ensure proper bundling of procedures. Use the correct codes for comprehensive procedures to avoid submitting separate line items for services that should be billed as a single unit.
7. Coding Mistakes for Screening Colonoscopies
Screening colonoscopies are among the most common procedures in gastroenterology. Coding errors could result in large balances for patients. Screening colonoscopies are generally covered without patient cost-sharing, while diagnostic colonoscopies may involve a higher cost to the patient.
How to Avoid
To ensure that screening colonoscopies are coded appropriately, it is imperative to code correctly.
Medicare service codes for screening colonoscopy are:
- G0121 – Screening Colonoscopy for individuals who is Not considered high-risk
- G0105 – Screening Colonoscopy for high-risk individuals
Commercial Insurance service codes for screening colonoscopy are:
45378 – screening colonoscopy with no polyp detected. Add modifier 33 to indicate colonoscopy was for screening purposes only.
For Carefirst, you might need to add the modifier PT to indicate screening. Use modifier 53 for discontinued procedures. Using proper modifier will ensure insurance covers the procedure in full, for patients 45 years or older.
8. Failure to Appeal Denied Claims
A denied claim is not necessarily the end of the road. Many gastroenterology practices lose revenue because billers do not take the time to find details for denials and do not create effective appeals.
How to Avoid
Denied claims should be addressed the same day you receive them. Review the remark codes carefully. Look ahead to see if there is any other information missing in your claim or your documentation. Correct all errors to avoid any further denials.
If any information needs to be added to the documentation, carefully create an addendum to your note. It might suffice to resubmit only the claim with corrections, but if needed, attach medical records, and add comments in box 19 of the claim form.
Don’t assume the person reviewing your claim will know all your abbreviations, shortcuts, and jargon. Add all pertinent information in detail. If resubmission of a claim fails to bring in payment, create a strong appeal with a brief note from the doctor about the necessity of the service. Follow your resubmissions and appeals closely.
9. Error in ICD-10 Code Selection
Selecting the wrong diagnosis code or a less specific code can lead to claim denials or improper reimbursements. It is easy to choose an ICD-10 code that is too general, unspecified, or one that does not accurately reflect the patient’s condition.
How to Avoid
Keep the current year’s ICD-10 book handy. Choose your diagnosis code as specific to the condition as possible. If a general code is used when a more specific one is available, the claim may be rejected or flagged for further review. Training, regular updates on ICD-10 codes, and good knowledge of LCDs are essential for ensuring coding accuracy.
10. Failure to Verify Insurance Coverage
Failing to verify a patient’s insurance coverage and benefits before performing procedures or tests is another common mistake. This can lead to denied claims or delayed payments, especially if the patient’s insurance has lapsed or does not cover a specific procedure.
How to Avoid
Establish a routine process for verifying insurance coverage for each patient before any procedures are performed. This should include confirming benefits, eligibility, and pre-authorization requirements. Don’t rely on clearing house or insurance portal information; they may have incorrect or old information which can be misleading. Make a list of questions from studying your previous denials and take the time to call insurance for verification of high-value services.
Final Thoughts
Gastroenterology billing involves complex procedures, evolving payer requirements, and specialty-specific coding rules. Managing these moving parts consistently requires both clinical coding knowledge and a structured revenue cycle process. That’s why many GI practices partner with specialists like FC Billing for Gastroenterology Billing Services, helping improve coding accuracy, reduce denials, and maximize reimbursement.
