What diagnostic code should be used for a patient's condition?

ICD-10 Diagnostic Coding Guidelines

When coding a patient's condition, use the ICD-10-CM system following standardized laterality conventions and specificity requirements, with the primary diagnosis listed first followed by any underlying or contributing conditions. 1

Core ICD-10 Coding Principles

Laterality Coding Standards

• Right side is always coded as 1 1
• Left side is always coded as 2 1
• Bilateral conditions are always coded as 3 1
• When no bilateral code exists and the condition affects both sides, assign separate codes for right and left 1
• Unspecified codes should only be used when no other code option is available 1

7th Character Requirements

• Certain ICD-10-CM categories require a 7th character for all codes within that category 1
• The 7th character must always occupy the 7th position in the data field 1
• If a code requiring a 7th character is not 6 characters long, use placeholder "X" to fill empty character positions 1

Coding for Administrative Encounters

Disability Examination Visits

• Use Z02.71 as the primary code for disability placard evaluation encounters 2
• List the underlying medical condition(s) causing the mobility limitation as secondary codes after Z02.71 2
• Document specific functional limitations and duration of disability to support medical necessity 2
• When underlying conditions have laterality, apply the standard 1-2-3 convention 2

Coding Accuracy Considerations

Documentation Requirements

• The diagnostic code assignment process depends on complete and accurate clinical documentation throughout the patient trajectory 3
• Potential error sources include incomplete information at admission, communication gaps between patients and providers, and variance between electronic and written records 3
• Rely directly on the ICD-10-CM classification system rather than secondary sources like DSM-5-TR for optimal coding accuracy 4

Persistent Coding for Chronic Conditions

• Chronic conditions should be coded persistently across encounters when clinically relevant 5
• Lack of persistent coding can result in incomplete capture of patient complexity and risk 5
• For sixteen common chronic conditions, persistent coding practices significantly impact risk adjustment calculations 5

Common Pitfalls to Avoid

• Never use unspecified laterality codes when specific right/left/bilateral codes are available 1
• Do not omit the 7th character when required by the code category 1
• Avoid coding from memory or secondary sources; always verify codes directly in the ICD-10-CM classification 4
• Do not fail to code underlying conditions when using administrative Z codes 2
• Ensure coder training addresses both intentional errors (upcoding, unbundling) and unintentional errors (misspecification) 3