Medical Billing Audit Checklist: Guide for Healthcare Practices

The claim may not trigger any error message when sent via the billing software but the claim may still have an un-supported procedure code, wrong modifier or even outdated insurance information. In the event that the payor detects that you have committed such an error, the claims would have been subjected to denial, adjustment of payment or documentation.

An audit checklist for medical billing may prove to be an important aid for medical practices as it helps in the analysis of the patient information, clinical information, medical codes, claims, payment process and adherence to the paying guidelines.

As a doctor, billing manager or practice administrator, the objective is not only identifying the errors. Through a proper auditing process, you will get to understand the reasons behind these errors.

What Is a Medical Billing Audit?

A medical billing audit is an activity which involves the analysis of the claims, documentation, coding, and payments of the claims.

The audit will establish if there was correct billing and correct documentation of the charges for the services provided.

The three major areas of the audit are:

Coding – Is the coding right according to the documentation as per the codes of CPT, HCPCS, ICD-10-CM, and modifiers?

Coverage and billing – Can the billing be able to meet the coverage, medical necessity, authorization, and billing criteria?

Payment – Does the payor follow the correct payment procedure in handling the billing?

The audit has to cover the whole billing lifecycle and not just the denied/ rejected claims.

Why Do Healthcare Practices Need Regular Medical Billing Audits?

A billing error does not mean that the insurance provider will automatically deny the claim. There are times that the claim is accepted without proper documentation and/or a wrong code.

According to the CMS FY 2025 Improper Payments Fact Sheet, An estimated percentage of improper payments for the Medicare Fee-for-Service is 6.55% that constitutes $28.83 billion.

This percentage involves different payment errors and is not considered a fraud rate.

For health care providers, this means that it is essential to check claims rather than trust payments only.

Regular medical billing audits can help the practice:

• Identify errors and erroneous billing.
• Recognize problems with eligibility and authorization.
• Study denial trends prior to escalation.
• Identify missing and underpayments.
• Study the accuracy of provider documentation.
• Find compliance concerns and training needs.

The most successful audit systems use this information to improve processes so that errors are less likely to be repeated.

Complete Medical Billing Audit Checklist

Use the below checklist to review the key steps in your revenue cycle. Each point below shows what needs to be reviewed by the reviewers as well as what issues need to be investigated further.

1. Patient Registration and Insurance Verification

The first step that you need to review will be patient information because even the correct service coding can experience payment issues when the claim includes incorrect patient demographics or insurance information.

Audit checklist:

• Ensure that the patient’s name, date of birth and ID information correspond to the registration information.
• Check the subscriber information along with the benefit coordination.
• Ensure that the right payer and plan have been identified by the staff.
• See if the service needs referral and prior authorization.

Finding: The patient switches insurance companies, yet the front office still uses the old insurance. The billing staff submits a claim to the old insurance company and gets a denied claim response.

Solution: Set up verification points to ensure eligibility before visits.

2. Clinical Documentation and Medical Necessity

The documentation in the patient’s chart must support the services and claims made in the claim form. While reviewing, please ensure that the documentation in the patient’s chart is compared with the billed services..

Audit checklist:

• Ensure that the records include service date and responsible provider.
• Examine any needed authentication and signatures.
• Reconcile the billing with services rendered.
• Examine medical necessity documentation.
• Determine if there is documentation to back up the E/M service.

General finding: The practice utilizes an elevated E/M code while the patient’s medical record does not document the required level of decision making or total time.

Resolution steps: Providers need to be educated on the E/M criteria and specific encounter reviews should be conducted to find recurrent discrepancies.

A good chart note describes a patient’s treatment; it is not just a billing note.

3. CPT, HCPCS, and ICD-10-CM Coding Accuracy

Coding errors could be made due to employees making use of outdated code selections, incomplete information or incorrect assumptions on what is expected by the payers.

Checklist for audit purposes:

• Codes for CPT and HCPCS must be the same as the procedures performed.
• ICD-10-CM codes must be correct for provider-confirmed diagnoses.
• Codes must be validated based on date of service.
• Validity of diagnosis and code sequencing must be evaluated.
• Modifiers must be evaluated based on suitability.
• Avoiding duplicate claims and unbundling.

For example, the doctor is performing two procedures on the same individual during the same encounter without thinking of adding an edit between the two procedures for coding purposes. The payer denies one procedure since the procedure does not meet the payer’s coding guidelines.

The reviewer should check the documentation, pertinent edits, and modifiers before editing the claim.

CMS maintains NCCI resources covering procedure-to-procedure edits and medically unlikely edits.

4. Prior Authorization and Payer Requirements

Problems with authorization could result in extra administrative effort being put into place, particularly for those fields that involve frequent processes.

Checklist for an audit:

• Get the authorization required before the provision of the service.
• Compare what was authorized with the services billed.
• Review the dates of authorization and visit limitations.
• Verify the criteria for referral and network.
• Look at payer-specific billing instructions.
• Determine services performed beyond authorized limits.

Remember that prior authorization does not assure payment. It is only the first step in the payment process.

5. Claim Submission and Clearinghouse Review

For a clean claim, correctness of procedure codes is not enough.

Billing identifier errors, date of service or place of service errors could lead to delayed claims processing despite proper supporting clinical documentation.

Audit checklist:

• Check rendering and billing provider identifiers.
• Check taxonomy and place of service codes.
• Identify diagnosis indicators for corresponding claim lines.
• Verify service dates, charge amounts and units.
• Check clearinghouse rejections and corrections history.
• Review payer claim acknowledgments.
• Check timely filing requirements.

Tip: Separate rejections and payer denials on the audit report. Clearinghouse rejection is something that happens prior to payer claim processing, whereas the denial is something that comes after payer claim processing.

6. Payment Posting and Reimbursement Reconciliation

The audit process does not end when the payment is released from the payer.

Billing personnel must check to see if payments, contractual adjustments, and balances are entered accurately.

Audit checklist:

• Compare payments to ERA/EOB details.
• Check the contractual adjustment.
• Research any anomalies in the underpayment.
• Check the patient liability calculation.
• Find duplicates or unapplied payments.
• Balance payment batches and deposits.
• Check the credit balance and overpayment.

For example, a payer releases a payment lower than expected under the contract. Failure to check the difference could mean a recoverable underpayment is overlooked.

An audit of a payment requires checking for meaningful differences between the real transaction and the contract details.

7. Denial Management and Accounts Receivable

Denial audits pinpoint situations in which claim audits would have difficulties finding issues. Instead of conducting audits on claims that were denied individually, conduct an audit of the denials on a grouped basis according to the type of denial, payer, procedure or process.

Audit checklist:

• Categorize denials depending on information provided by CARC and RARC.
• Identify repetitive denials by payers and services.
• Review the status of correction, appeal and resubmission.
• Check outstanding accounts receivable issues.
• Ensure timely response to payers’ and appeals’ deadlines.
• Check recurring issues relating to authorizations and documentation.
• Ensure follow-through by staff.

Highly recurring eligibility denials could be an indication of registration issues, and not coding issues. Likewise, recurring documentation denials could be an issue for staff training, rather than billing edits.

Medical Billing Audit Checklist: Quick Reference Table

Audit Area	What to Review	Common Risk
Patient registration	Demographics and active coverage	Incorrect payer information
Documentation	Encounter notes and medical necessity	Unsupported services
Medical coding	CPT, HCPCS, ICD-10-CM, modifiers	Incorrect or conflicting codes
Authorization	Approvals, dates, visit limits	Missing authorization
Claims submission	Identifiers, units, service dates	Rejections and filing delays
Payment posting	ERA/EOB and contractual adjustments	Underpayments
Denial management	Denial reasons and follow-up	Repeat denials
Compliance	Policies, records, corrective actions	Unresolved compliance risks

Practices can adapt this table to their specialty, payer mix, claim volume, and internal compliance responsibilities.

How to Conduct a Medical Billing Audit Step by Step

A good audit of medical bills is conducted in a systematic manner. Without setting a scope and making any corrections, it’s all for nothing.

Step 1: Scope of the Audit

Identify the type of claim, provider, payer, and/or service that will be audited. An office can opt to audit denied cardiology claims, high dollar E/M services, or chronic authorization problems. 

Step 2 :Select an appropriate sample of claims

Claims are to be picked from multiple providers, payers, services and payment outcomes. Discuss a select few claims as well as a review of high-risk services or unusual billing practices. It is not always possible to fix the number of claims up front.

Step 3: Compare the Claim to the Supporting Documentation

Look at claims, clinical, coding, authorization documents and payment data.

Compare claims with the service requirements as they existed on the date of service.

Step 4 : Analyze the issue by the severity level

Describe a particular discrepancy, its reason and consequences.

A good audit should separate out the documentation errors, coding problems, payment inconsistencies, and the inability to comply with the rules.

Step 5: Take Actions

Determine a person responsible for each problem.

These actions may include training, updating billing systems, physician education, claim correction and conducting a compliance audit.

Step 6: Repeat the Audit 

Perform a follow up audit of claims or processes following the implementation of appropriate measures.

In case of repeated problems, it is necessary to investigate processes and not train employees once again.

Internal vs. External Medical Billing Audits

Both approaches serve a purpose, but they offer different operational advantages.

Internal Audit	External Audit
Uses staff or internal compliance resources	Uses independent reviewers
Supports regular operational monitoring	Offers an outside assessment
Helps identify routine workflow errors	Can identify overlooked risks
Allows faster feedback to billing teams	May provide specialized expertise
May face internal resource limitations	Requires careful coordination and record access

A healthcare practice may decide to conduct periodic internal audits and/or an external audit if it identifies issues that are complex in coding, has a high frequency of reimbursement errors, or has compliance problems.

The following are some of the common medical billing audit mistakes:

If the billing folks don’t take time to consider where the problem is coming from, these folks are the ones who can get in the way of the audit process.

 

Audit based on only denied claims: Claims that have been accepted and paid could be audited incorrectly. All paid, adjusted and denied claims should be included in the auditing process.

Ignoring date of service guidelines: Using current coding guidelines on previous claims could yield wrong conclusions. The audit must be conducted in accordance with the relevant codes and policies to the claim being audited.

In the coding component alone: Coding matters; however, other factors like eligibility, authorization, posting and follow up may also be relevant for the claim.

Failure to act on action documentation: If an audit report is not followed up and acted upon after the audit, it becomes a worthless document.

If they think there was a payment error, they don’t assume it was a fraud: If they believe that the payment has been misplaced, they do not assume it was a fraud.

How Often Should a Medical Practice Conduct Billing Audits?

The schedule of performing audits may vary from one practice to another and is at their discretion to perform internal audits as well as an external audit of their choice.

A practical way would be conducting periodic and occasional audits.

Weekly audits: Look into the causes behind rejections and denials and any oddity in claims.

Monthly audits: Analyze sample claims, coding mistakes and discrepancies in payments.

Quarterly audits: Discover trends among the providers, specialty and payers.

Annual audits: Evaluate the billing policies and compliance issues and corrections of past audits.

These are suggested time durations and not the frequency for conducting federal audits.

Healthcare organizations are supposed to conduct audits frequently in case of introduction of new services and any change in the organization like billing anomalies.

The HHS Office of Inspector General identifies auditing and monitoring as important elements of an effective compliance program.

Key Metrics to Track After a Medical Billing Audit

The final audit report should help practice leaders measure progress.

Metric	What It Reveals
Coding error rate	Frequency of coding discrepancies in reviewed claims
Initial denial rate	Claims denied during initial payer processing
Clean claim rate	Claims passing defined initial submission checks
Days in accounts receivable	Average time receivables remain outstanding
Underpayment variance	Differences between expected and actual allowed payments
Corrective action completion	Progress toward resolving audit findings

Consistently monitor these metrics and keep track of how the practice computes each one.

An increasing denial rate, for instance, indicates possible issues at the front end, while a growing aged receivables rate indicates possible follow-up problems.

Looking at several metrics provides a better assessment of how well the billing is being done.

Frequently Asked Questions

What should be included in a medical billing audit checklist?

A medical billing audit checklist needs to incorporate patient registration, insurance verification, documentation, coding, prior authorization, claims submissions, payments postings, denial management, and compliance.

Who conducts a medical billing audit?

Medical billers, coders, supervisors, internal compliance officers, or external auditors can conduct such reviews depending on the objective of the audit.

How long is a medical billing audit?

It depends on the number of claims, availability of documentation, scope of the audit and its complexity. A focused medical billing audit can require significantly less effort compared to a general compliance audit of an entire facility.

 

Can medical billing audits decrease claim denials?

The audit can be used to determine the repetitive causes of denials, which are coding errors, eligibility issues, and authorization issues. The practice needs to conduct necessary remediation and check future claims to find out whether there were fewer denials.

What is the difference between a medical coding audit and a billing audit?

A medical coding audit focuses on the choice of codes and documentation of the clinical evidence to support it. A medical billing audit focuses on the more extensive process, which might involve eligibility, authorizations, submission of claims, coding, payment, and reconciliation of accounts.

Are medical billing audits required?

The requirements vary depending on the agreements of an organization, participation in programs, laws applicable to the entity, and the need for compliance. Not all health care organizations have to conduct audits according to some universal schedule. An organization should assess its particular requirements.

What will happen in case an overpayment is found in an audit?

The organization has to conduct an investigation and decide whether there was indeed an overpayment, measure its amount and take action to correct the issue.

Improve Claim Accuracy With a Structured Billing Audit

The use of a medical billing audit checklist offers healthcare organizations an easy method for reviewing claims and identifying any issues in order to improve internal control systems.

Nevertheless, completing the checklist alone does not solve recurring problems; standard documentation procedures, thorough claim reviews, accountability of employees, and corrective measures need to be ensured.

Through regular medical billing audits, together with employee training and revenue cycle management, healthcare organizations can deal with their weak points in advance.