Navigating the Coding Minefield: Labs Struggle with RCM Rejections Amid Rising Scrutiny from Payers

Clinical laboratories and pathology groups face mounting pressure as they navigate increasingly complex coding requirements for laboratory billing and lab revenue cycle management (lab RCM) for diagnostic tests. Constant regulatory updates, payer-specific rules, and the increasing use of automated claim review systems, compounded by outdated laboratory information system (LIS software) unable to catch errors before submission, have driven up claim rejections, denials, and post-payment clawbacks, creating significant financial and operational strain across the industry.

"Every fiscal year, new coverage determinations are released, usually based on CMS guidelines, and many payers follow those closely," said Aram Avakyan, a laboratory revenue cycle management expert with deep insight into the lab billing space. "Sometimes, it's a drastic change. Other times, it's minimal. Regardless, we've seen the noose tighten. It's become harder to reach that low-hanging fruit."

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The Most Common Causes of Lab Rejections 

According to Avakyan and industry data, the most common causes for lab claim rejections include:

• Outdated or incorrect coding due to frequently updated CPT and ICD-10 codes
• Evolving medical necessity documentation requirements
• Missing or inaccurate patient and payer data, often from human error
• Improper use of modifiers or units
• Errors in bundling and unbundling protocols
• Missing or unrequested prior authorizations

These long-standing challenges have escalated in recent years, particularly with the rise of automation and AI tools on the payer side.

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The Growing Threat of Post-Payment Scrutiny and AI-Driven Audits

"Payers are reviewing claims more closely than ever before," Avakyan explained. "If the CPT code does not align with the diagnosis ICD-10 code, the payer will likely reject the claim. Even if a claim makes it through initially, they might claw it back months later."

This post-payment scrutiny is a growing concern for labs, especially when claims involve high-dollar tests such as flow cytometry or advanced immunochemistry.

"Tests that cost more than $300 or $500 per unit are much more likely to be scrutinized," said Avakyan. "You won't see 10 units of a CPT code getting reimbursed easily as you might have five or ten years ago."

The Role of AI in Rising Denial Rates 

Some industry observers believe that artificial intelligence holds a significant role in the growing rate of denials, enabling payers to flag questionable claims that would have been too time-consuming for human reviewers.

"I can't confirm it 100 per cent, but it's an absolute possibility," said Avakyan. "We're working on similar AI-driven tools, where the lab revenue cycle management module housed within the all-in-one LigoLab Informatics Platform reviews combinations of ICD-10 and CPT codes and flags inconsistencies before submission. It's reasonable to think payers are doing the same."

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Prevention Is Key: Laboratory Billing Best Practices 

Keep the First-Pass Ratio as High as Possible 

Avakyan emphasized that preventing denials is most effectively achieved through a proactive, well-structured laboratory billing process.

"The name of the game these days is to avoid clawbacks and denials altogether," he said. "It's about keeping that first-pass ratio as high as possible."

Six Strategies to Reduce Rejection and Denial Rates

Based on LigoLab's internal data and client outcomes, Avakyan recommended the following strategies:

Regularly Update Systems: Ensure laboratory billing software reflects the latest CMS codes and local coverage determinations.

Pre-Submission Audits: Review claims before submission to identify documentation errors and ensure coding alignment.

Monitor Regulatory Changes: Stay current with CMS bulletins and payer policy shifts.

Engage in Ongoing Education: Participate in CMS webinars and offer internal coding training to enhance skills.

Hire Certified Coders: Employ experienced lab billing staff who understand the nuances of CPT, ICD-10, and payer-specific requirements.

Implement Smart Claim Review Systems: Leverage advanced laboratory billing solutions that apply hard stops or warnings when claims are likely to be denied by the payer.

Configurable RCM Tools for Payer-Specific Control

Avakyan described how his lab billing software team has developed configurable revenue cycle management tools that empower medical labs to tailor their claim scrubbers to the specific requirements of different payers or payer groups.

"Our billing software for labs checks against updated NCD and LCD lists, monitors MUEs, and flags nonspecific diagnosis codes," he said. "And our rule engine can be configured for any lab's unique RCM cycle workflow. It's all about giving the lab control and visibility before the claim leaves the lab billing platform."

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The Cost of Inaction

As scrutiny intensifies and AI-driven audits become more common, clinical laboratories and pathology groups can no longer afford to treat lab billing and coding as a back-office function. It is now a frontline strategy for preserving revenue and improving profitability.

"The preemptive approach is essential," Avakyan concluded. "Because once you're in the back-and-forth of appeals or clawbacks, it's already too late. That's when it becomes expensive, both in time and dollars."

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Unify, Automate, and Maximize: How the LigoLab Platform Transforms Laboratory Revenue Cycle Management

A Comprehensive, End-to-End Medical LIS & Lab RCM Solution

The all-in-one LigoLab Informatics Platform is a comprehensive, end-to-end diagnostic lab software solution that unifies and optimizes the operational and financial aspects of pathology and clinical laboratory management. Built for scalability, compliance, and efficiency, the platform seamlessly integrates advanced LIS laboratory information system functions with modern lab revenue cycle management tools, enabling testing organizations to streamline workflows, eliminate silos, and maximize reimbursement.

Real-Time, Rules-Based Architecture

LigoLab stands out for its real-time, rules-driven architecture. It seamlessly unifies the diagnostic and billing sides of the laboratory. This integrated approach ensures accurate coding, complete documentation, and clean claims from the outset. By automating complex lab billing processes, such as CPT and ICD code validation, insurance eligibility verification, claim scrubbing, and compliance with MUE, NCD, and LCD requirements, LigoLab helps minimize denials, accelerate cash flow, and reduce administrative overhead.

Full Visibility and Proactive Revenue Integrity 

The platform also features customizable dashboards, audit trails, and pre- and post-billing analytics, providing unparalleled visibility and control over every step of the laboratory billing process. With built-in RCM tools for prior authorization management, payer-specific rules, and automated appeals workflows, LigoLab empowers labs to manage revenue integrity proactively.

Whether you're scaling an anatomic pathology practice or a growing reference lab, LigoLab's modular, cloud-based solution adapts to your needs and supports your long-term success.

Discover More: Essential Anatomic Pathology LIS Software Features to Optimize Laboratory Workflow

Ready to Take Control of Your Lab's Financial Performance? 

Connect with a LigoLab product specialist today to see how a unified medical LIS software with an integrated lab billing module can transform your laboratory’s operations and boost profitability. See what’s possible when LIS and RCM workflows merge into one unified source of truth.

Take Action: Contact a LigoLab Product Specialist Today!

Frequently Asked Questions About Laboratory Billing Rejections and Coding Compliance

Why are lab claim rejections and denials increasing?

Claim rejections are rising due to a combination of more frequent regulatory updates, payer-specific coding requirements, and the growing use of automated and AI-driven claim review systems on the payer side. Even claims that pass initial review are increasingly subject to post-payment audits and clawbacks, particularly for high-dollar tests.

What are the most common causes of lab billing rejections?

The most common causes include outdated CPT and ICD-10 codes, incomplete or inaccurate patient and payer information, incorrect use of modifiers or units, coding errors related to bundling and unbundling, and medical necessity documentation requirements. 

What is a first-pass claim ratio, and why is it important?

The first-pass claim ratio measures the percentage of claims accepted and reimbursed on the first submission (without rejection or denial). A higher ratio means faster reimbursement, less time in accounts receivable, and fewer resources spent on appeals, directly improving a lab's cash flow and profitability.

How does LigoLab's platform help prevent claim rejections before submission?

LigoLab's lab billing module reviews combinations of ICD-10 and CPT codes, flags inconsistencies, checks against updated NCD and LCD lists, monitors Medically Unlikely Edits, and applies payer-specific rules, all before a claim is submitted. This proactive approach significantly reduces the risk of rejection and post-payment clawbacks.

What is a post-payment clawback, and how can labs protect themselves?

A post-payment clawback occurs when a payer recoups previously paid claim amounts after a subsequent audit reveals coding errors or compliance issues. Labs can protect themselves by implementing pre-submission audits, regularly updating lab billing software to reflect current CMS guidelines, and utilizing configurable claim scrubbers that catch potential issues before submission.

How does AI affect lab claim denials?

Payers are increasingly using AI and automated tools to flag claims where CPT and ICD-10 codes don't align or where billing patterns appear inconsistent with clinical norms. It has made it harder for labs to pass high-dollar claims without precise documentation and coding. LigoLab is developing similar AI-driven tools on the lab side to flag potential issues before claims are submitted.

What lab revenue cycle management best practices should labs adopt to reduce denials?

Labs should regularly update their laboratory billing systems with the latest CMS codes, conduct pre-submission claim audits, monitor regulatory changes, invest in ongoing coder training, hire certified coders, and implement smart claim review systems with hard and soft stops that catch likely denials before submission.

Can LigoLab's rule engine be configured for different payers?

Yes. LigoLab's rule engine is fully configurable, enabling customers to tailor claim scrubbers and billing workflows to the specific requirements of individual payers or payer groups. This gives labs granular control and visibility at every stage of the laboratory billing process.