Medical billing and coding errors are among the top causes of claim denials—and they can be costly. From missed reimbursements to delayed cash flow, even small mistakes can create big setbacks for your practice. According to a 2024 report, the problem with denials boils down to bad data. Many denials are preventable, and the process of protecting revenue starts long before the claim is submitted. In fact, it begins the moment your patient schedules an appointment. By identifying and addressing common errors—such as eligibility issues, incorrect coding, or underutilization of your practice management system—you can improve your clean claim rate and ensure faster payments.
Let’s take a deeper look at the most frequent issues and how to prevent them.
1. Patient Eligibility Issues
Eligibility verification is one of the most basic—and most critical—steps in the revenue cycle. Denials frequently occur because a patient’s insurance coverage is inactive or their information is simply entered incorrectly.
Example: A patient’s coverage may have terminated at the end of the previous month, but without verifying eligibility, your front desk may not discover this until after services are rendered and the claim is denied.
Best Practice: Use your practice management system or payer portals to verify eligibility at least 48–72 hours before the appointment. Many systems allow for automatic batch checks for upcoming appointments. Verifying ahead of time gives staff an opportunity to resolve issues—such as expired insurance or incorrect ID numbers—before the patient arrives.
2. Incomplete Verification of Benefits
Once you have properly verified eligibility, reviewing the types of benefits your patient is eligible for is the next key step. Even if a patient has active coverage, failing to verify specific benefits can result in avoidable denials.
Example: A patient schedules an annual physical assuming it’s covered. However, their plan defines “annual” as once every 12 months, not once per calendar year. If their last visit was in March and they return in January, the claim will likely be denied.
Best Practice:
Don’t just check for active insurance—confirm that the services you plan to provide are covered under the patient’s benefit plan, and that any frequency limitations or pre-authorizations are addressed.
3. Inaccurate Coding
With over 90,000 unique billing and clinical codes in use, medical coding is a complex and ever-evolving process. Using outdated or incorrect codes or failing to code to the highest level of specificity often leads to denials.
There are multiple code sets that are updated on an annual basis. Most commonly known are Current Procedural Coding (CPT), HCPCS, and ICD-10. Updates to CPT and HCPCS are published and made effective January 1st each year. To prepare your practice for the upcoming changes that may impact the services you bill, the new, revised, and deleted codes should be reviewed immediately when the new publication is released.
ICD-10 updates become effective annually on October 1st. As more specific diagnoses are released, payers may deny claims that used to be approved for lack of specificity. Diagnosis should be coded to the highest specificity to avoid denials.
Other common coding denials relate to bundling services. The National Correct Coding Initiative Procedure-to-Procedure Coding Edits is made available by CMS and is updated quarterly. When coding multiple procedures on a claim, this resource identifies if the codes are billable together.
In addition to the Procedure-to-Procedure Coding Edits, CMS also provides Medically Unlikely Edits (MUE). Denials will occur when the maximum units are exceeded for a procedure code. MUEs provide the number of times a procedure can be billed on a claim for a single date of service. The rational is also included for each CPT to indicate the reasoning for the max number of units.
Example: Billing CPT code 93000 (EKG) along with a preventive visit (e.g., 99396) without appending modifier 25 when the EKG was medically necessary and separately identifiable could result in the EKG being denied.
Best Practice:
Regularly review CPT, HCPCS, and ICD-10 code updates.
Use CMS tools such as the National Correct Coding Initiative (NCCI) Edits and Medically Unlikely Edits (MUEs) to check for code pair restrictions and unit limits. For example, if the MUE for a specific injection is “1,” billing it twice on the same date of service will lead to denial unless appropriately justified.
4. Missing Prior Authorizations and Incorrect Payer Billing
Some of the most frustrating denials stem from administrative oversight—billing the wrong payer, missing a required authorization number, or using outdated plan information.
Example: A claim is submitted to a commercial payer when the patient has recently transitioned to Medicaid. Not only is the claim denied, but timely filing limits with the correct payer may expire before the error is discovered.
Best Practice:
- Confirm insurance details at every visit—not just the first.
- Set up flags and alerts in your practice management system for services requiring prior authorization.
- Educate staff on payer-specific rules and use customized system edits to prevent known errors before claims are sent.
5. Underutilization of Your Practice Management System
During the coding and billing process, you can expect human error to some extent. These errors can include simply billing the incorrect payer or missing the authorization number on a claim for payers where it is known to be required. With each claim resubmission and corrected claim sent, the odds of reimbursement decrease. Your practice management system can be your best defense against denials—if used effectively. Many practices don’t take full advantage of tools like customizable claim edits, eligibility automation, and real-time alerts.
Taking the appropriate steps to utilize existing resources can minimize common denials, turning into faster and more accurate claims payment.
Example: A practice fails to set up claim edit rules to flag missing referring provider NPI for specialist visits. Claims are submitted, denied, and must be manually corrected—slowing down cash flow.
Best Practice:
Regularly review system reports, track your clean claim rate, and update your internal edits to match common denial trends. Leverage automation wherever possible to reduce manual entry errors.
From Appointment to Payment, Precision Matters
Every step of the patient’s journey impacts your reimbursement. By prioritizing accuracy in eligibility checks, benefits verification, coding practices, and claim submission workflows, your organization can significantly reduce preventable denials. Establish a proactive process that includes regular training, system optimization, and continuous monitoring of denial trends. Doing so will not only increase cash flow but also reduce administrative burden and improve the patient financial experience. Taking the time to invest in these preventive strategies today will save your team time, money, and frustration tomorrow.
Ready to take the next step toward preventing denials before they can occur? Check out our white paper, Denials in 3D, for perspectives from across the industry on how to reduce denials, expedite cash flow, and improve the overall patient financial experience.
