What is the ICD-10 (International Classification of Diseases, 10th Revision) code for a patient presenting with left-sided weakness or palsy?

ICD-10 Coding for Left-Sided Weakness/Palsy

For left-sided weakness or palsy, use ICD-10 code G81.92 (Hemiplegia, unspecified affecting left dominant side) or G81.94 (Hemiplegia, unspecified affecting left nondominant side), depending on the patient's dominant hand. 1

Understanding ICD-10 Laterality Coding

The ICD-10-CM system uses a standardized approach to indicate laterality in diagnosis codes:

• Right side is always coded as "1" 1
• Left side is always coded as "2" 1
• Bilateral is always coded as "3" 1

This laterality designation appears in the final character of the code, regardless of which digit position it occupies (4th, 5th, or 6th digit). 1

Specific Code Selection for Left-Sided Weakness

Primary Hemiplegia Codes (G81 Category):

• G81.92: Hemiplegia, unspecified affecting left dominant side 2
• G81.94: Hemiplegia, unspecified affecting left nondominant side 2

The distinction between dominant and nondominant side is clinically significant and must be documented to select the appropriate code. 2

Alternative Codes Based on Etiology:

If the underlying cause is known, more specific codes should be used:

• G81.02/G81.04: Flaccid hemiplegia affecting left side (dominant/nondominant) 2
• G81.12/G81.14: Spastic hemiplegia affecting left side (dominant/nondominant) 2
• I69.35x: Hemiplegia following cerebral infarction affecting left side 2
• I69.05x: Hemiplegia following nontraumatic subarachnoid hemorrhage affecting left side 2

Critical Coding Principles

Always code to the highest level of specificity available in the medical documentation. 3, 2 Unspecified codes should only be used when there is no other code option available or when documentation does not support a more specific diagnosis. 1

Documentation Requirements:

• Determine if weakness is complete paralysis (hemiplegia) or partial (hemiparesis) 2
• Document whether left side is dominant or nondominant 2
• Identify underlying etiology if known (stroke, trauma, etc.) 2
• Specify if weakness is flaccid or spastic in nature 2

Common Pitfalls to Avoid

Do not rely solely on secondary sources like DSM-5-TR for ICD-10 coding. 3 The ICD-10-CM itself and the ICD-10-CM Official Guidelines for Coding and Reporting are the authoritative sources and should be consulted directly. 3, 2

Verify code accuracy, especially early in documentation practice. 4 The transition to ICD-10's vastly larger and more detailed code set requires careful attention to selecting the most accurate code. 4

Distinguish between related conditions that require separate coding:

• Hemiplegia/hemiparesis (motor weakness) is distinct from aphasia (language disorder) 1, 5
• Facial palsy (cranial nerve VII) uses different codes than limb weakness 1, 6
• Dysarthria (articulation disorder) is coded separately from hemiplegia 7