Medical Billing 101 – Free Denial Code, CPT & RCM Guides

Guide to building a CO97 denial tracking dashboard in your PM system

Working CO 97 denials one claim at a time will always be reactive. The same NCCI bundling mistake can repeat across dozens of claims before anyone notices a pattern, because most billing teams review denials individually rather than in aggregate. A denial tracking dashboard flips that: instead of asking “why did this claim deny,” it … Read more

Global surgical package guide: reference page on 10-day and 90-day global period billing rules

One of the most common reasons a legitimate, separately payable service gets denied isn’t a coding mistake. It’s a misunderstanding of what’s already bundled into the surgery itself. The global surgical package is the single biggest source of CO 97 denials tied to surgical billing, and it trips up experienced coders just as often as … Read more

I Called Three Commercial Payers About Patellofemoral Arthroplasty Coding: 27438 vs. 27599

Short answer: CPT 27599 (unlisted femur/knee procedure) is the more technically accurate code for patellofemoral arthroplasty (PFA). But across three commercial payers I contacted directly, 27438 processes and pays without a flag while 27599 routes into manual pricing at 60–80% of the 27447 allowable. The right code depends on your payer, your documentation, and whether … Read more

I Called UnitedHealthcare, Cigna, and Aetna About Their CO-197 Criteria

Here’s What the Reps Actually Said vs. What the Policy States A CO-197 denial means the service required prior authorization and either it wasn’t obtained or it wasn’t valid. That’s what the policy says. It’s clean, short, and almost completely useless when you’re staring at a remit with a $4,200 denial and a 45-day timely … Read more

CPT 64772 vs 64999: Thumb CMC Joint Denervation Coding Guide

Category: Surgical Billing | Nerve Surgery | Orthopedic Hand Surgery Coding Reading Time: 9 minutes Last Updated: June 2026 CPT 64999 is the more defensible billing choice for selective thumb CMC joint denervation. This applies when the surgeon has addressed the superficial radial nerve branches. It also applies when the lateral antebrachial cutaneous nerve branches … Read more

Billing Medicare Secondary When Global Imaging Code (74181) Was Paid by Primary Insurance: A Complete Guide to the CMS Anti-Markup Rule

Introduction: The Conflict Between Commercial and Medicare Billing Rules Medical billing professionals who handle coordination of benefits claims frequently encounter a challenging scenario: a global imaging code such as CPT 74181 (MRI abdomen without contrast) was correctly billed and paid by a commercial primary insurer, but the claim must now be submitted to Medicare as … Read more

When to Use Unlisted CPT Codes Without Getting Audited

What Are Unlisted CPT Codes and Why Do They Exist Every CPT code in the AMA’s procedural terminology system describes a specific, defined service. Most of the time, a provider can find a code that accurately fits what was performed. But medicine moves faster than codebooks. New surgical techniques, emerging technologies, and rare procedures regularly … Read more

How to Write a Comparable Procedure Narrative for Unlisted CPT Codes

Why the Comparable Procedure Narrative Exists When a provider bills an unlisted CPT code, there is no relative value unit attached to it. There is no national fee schedule rate. No automated adjudication system can price the claim because the code carries no defined descriptor. That means a human reviewer at the payer sits down … Read more

Category III CPT Codes vs Unlisted Codes: Which One Should You Bill

Why This Decision Matters More Than Most Billers Realize When a provider performs a procedure that has no obvious home in the standard CPT code set, two options appear on the table. The first is a Category III CPT code, sometimes called a T-code because the fifth character is always the letter T. The second … Read more