ICD-10 Guide

Lynch Syndrome

ICD-10 Coding for Lynch Syndrome(Z15.09, Z80.0)

PRIMARY SPECIALTYGenetics

COMPLEXITYHigh

LAST UPDATED09/15/2025

Sam Tuffun, PT, DPT

Physical Therapist | Medical Coding & Billing Contributor

Diagnosis Overview

What is Lynch Syndrome?

Essential facts and insights about Lynch Syndrome

Key Clinical Considerations:

Increased risk of colorectal and endometrial cancers
Presence of mismatch repair deficiency (dMMR)
Family history of Lynch syndrome-associated cancers

Clinical Information

Clinical Criteria & Documentation Requirements

Family history of cancers, especially colorectal and endometrial
Genetic testing results for MMR genes (MLH1, MSH2, MSH6, PMS2)
Clinical findings consistent with Lynch syndrome

Coding Guidelines

Usage Guidelines & Examples

Use Z15.09 for genetic susceptibility; avoid using for unrelated cancers.
Common errors include misclassifying Lynch syndrome as sporadic cancers.

Code Exclusions

Important Exclusions

Familial adenomatous polyposis (FAP)
Other hereditary cancer syndromes

Specialty Focus

Primary Specialty

Genetics

Specialty Applications

Individuals with a family history of Lynch syndrome-related cancers
Genetic counseling and testing clinics

Coding Complexity

High Complexity

This diagnosis requires careful attention to:

Comprehensive clinical documentation
Accurate code selection based on clinical criteria
Proper exclusion considerations
Specialty-specific coding guidelines

Documentation

Documentation Templates

Billing Information

Billing Considerations

Ensure proper documentation for billing
Verify code specificity requirements
Check for any additional codes needed
Review payer-specific guidelines

Common Issues

Insufficient clinical documentation
Incorrect code selection
Missing supporting diagnoses
Timing and frequency documentation

Frequently Asked Questions

Documentation requirements?

Document family history, genetic test results, and clinical findings.

Billing considerations?

Ensure accurate coding for genetic tests and associated cancers.

Lynch Syndrome

Diagnosis Overview

Key Clinical Considerations:

Clinical Information

Clinical Criteria & Documentation Requirements

Coding Guidelines

Usage Guidelines & Examples

Code Exclusions

Important Exclusions

Related ICD-10 Codes

Related CPT Codes

Specialty Focus

Primary Specialty

Specialty Applications

Coding Complexity

Documentation

Documentation Templates

Billing Information

Billing Considerations

Common Issues

Frequently Asked Questions

Documentation requirements?

Billing considerations?

Lynch Syndrome

Diagnosis Overview

Key Clinical Considerations:

Clinical Information

Clinical Criteria & Documentation Requirements

Coding Guidelines

Usage Guidelines & Examples

Code Exclusions

Important Exclusions

Related ICD-10 Codes

Related CPT Codes

Specialty Focus

Primary Specialty

Specialty Applications

Coding Complexity

Documentation

Documentation Templates

Billing Information

Billing Considerations

Common Issues

Frequently Asked Questions

Documentation requirements?

Billing considerations?