A buyer's guide
Medical coding audit services: find where the money leaks, not just the score
A coding audit only earns its cost if it tells you where the revenue is leaking, not just that it is. A percentage-accurate score is a grade. A root-cause finding is a fix. The difference decides whether next quarter's charts code any better than this quarter's did.
Reviewed by Amanda Chuderewicz, Director of Coding & Auditing Services
A medical coding audit is an independent review of coded charts against the documentation, official coding guidelines, and payer policy. It checks whether the assigned ICD-10-CM, CPT, and HCPCS codes, the modifiers, the units, and the diagnosis links are correct, and whether the claim would survive a payer or a compliance review.
The point is not the score. Any audit can return an accuracy percentage. A useful audit returns the pattern behind the errors: the specialty, the provider, the documentation gap, or the rule that keeps producing the same denial, so the next charts are coded differently.
Audits run before the claim goes out (pre-bill) or after (post-bill), and they range from broad compliance reviews to payer-specific and specialty-specific deep dives. What follows is the types, what a good audit surfaces, and how MediCodio runs them.
Types of audit
Four audits, four questions they answer
The right audit depends on the question you are trying to answer. Each catches a different kind of leak.
Pre-bill audit
Charts are reviewed before submission, so errors are corrected before they become denials. It protects revenue on the way out rather than chasing it on a remittance weeks later.
Post-bill audit
Submitted charts are reviewed to quantify accuracy, surface systematic errors, and find undercoding that paid but paid less than the encounter earned. It is how you find the pattern.
Compliance audit
A focused review against coding guidelines, NCCI edits, MUE limits, and coverage policy to reduce exposure before a payer or a regulator finds it first.
Payer or specialty audit
A deep dive on one payer's rules or one specialty's documentation, where denials or underpayments concentrate and a general audit would miss the cause.
How it works
How MediCodio audits a chart
Charts are re-coded against the documentation
The audit re-derives the correct codes from the same documentation the original coder saw, so a disagreement is attributable to a specific chart, rule, and code rather than a general impression.
Every finding is traced to its cause
Each error is logged against the specialty, provider, documentation gap, or rule that produced it. That is what turns a score into a fix, because it names what to change.
Credentialled auditors make the call
AAPC- and AHIMA-credentialled coders and auditors (CPC, CCS, CRC, RHIT, CPC-I) apply official guidelines and payer policy. Where the audit and the original coding disagree, the auditor's determination is the reference.
Findings come back as actions
The result is a set of root causes and the documentation or coding changes that address them, not a single accuracy figure, so the next cycle of charts is measurably better.
AI plus certified auditors
The AI finds the outliers. The auditor makes the call.
MediCodio pairs CODIO with certified auditors. The AI validates code sets against NCCI, MUE, and LCD/NCD policy at scale and surfaces the charts most likely to carry an error, so the audit sample is not random and the auditor's time goes where the risk is.
A credentialled auditor then reviews each flagged chart against the documentation and makes the determination. Every code decision, in coding and in audit, carries the documentation passage and the rule behind it, so a finding can be defended to a provider or a payer rather than asserted.
Accuracy, defined
98% first-pass, measured against a credentialled reference
MediCodio reports 98% first-pass coding accuracy across deployments since 2023, measured at the code level on production charts against a reference review by AAPC- and AHIMA-credentialled coders and auditors applying official guidelines and payer policy to the same documentation. Coverage spans 35+ specialties. The figure that should drive a decision is the one produced on your own charts, audited by your team.
FAQ
Frequently asked questions
What is a medical coding audit?
A medical coding audit is an independent review of coded charts against the documentation, official coding guidelines, and payer policy. It verifies that the assigned ICD-10-CM, CPT, and HCPCS codes, modifiers, units, and diagnosis links are correct and would survive a payer or compliance review, and it identifies the patterns behind any errors.
What is the difference between a pre-bill and post-bill coding audit?
A pre-bill audit reviews charts before submission so errors are corrected before they become denials. A post-bill audit reviews submitted charts to quantify accuracy, find systematic errors, and surface undercoding that paid less than the encounter earned. Pre-bill protects revenue on the way out; post-bill finds the pattern to fix.
What should a good coding audit tell me?
More than a score. A useful audit returns the root cause behind the errors, the specialty, provider, documentation gap, or rule that keeps producing them, and the specific changes that address each one. That is what makes the next cycle of charts code better rather than just measuring the last one.
How does MediCodio run coding audits?
MediCodio pairs CODIO with AAPC- and AHIMA-credentialled auditors. The AI validates code sets against NCCI, MUE, and LCD/NCD policy and surfaces the charts most likely to carry an error, and a certified auditor reviews each flagged chart against the documentation. Every finding is traced to the rule or documentation gap that caused it.
Is the audit process HIPAA compliant?
MediCodio is HIPAA compliant, ISO/IEC 27001:2022 certified, and Veradigm Connect certified, with encrypted PHI exchange, role-based access controls, and an audit log on every code and audit decision so each finding traces back to the documentation and the rule behind it.
