What is the ICD‑10‑CM diagnosis code for a left second toe contusion with sub‑ungual hematoma and the CPT code for nail removal?

ICD-10-CM and CPT Coding for Left Second Toe Contusion with Subungual Hematoma

For a left second toe contusion with subungual hematoma, use ICD-10-CM code S90.212A (Contusion of left lesser toe(s) with damage to nail, initial encounter) and CPT code 11730 (Avulsion of nail plate, partial or complete, simple; single) or 11740 (Evacuation of subungual hematoma) depending on the procedure performed.

ICD-10-CM Diagnosis Code

The appropriate diagnosis code is S90.212A, which specifically captures:

• S90.2 = Contusion of toe(s)
• 12 = Left lesser toe(s) (2nd through 5th toes)
• A = Initial encounter

This code is more specific than the unspecified codes and accurately describes both the contusion and the nail damage (subungual hematoma). The seventh character "A" indicates this is the initial encounter for this injury.

Alternative Codes to Consider:

• Use S90.212D for subsequent encounters during healing
• Use S90.212S for sequelae (late effects) if applicable

CPT Procedure Codes

The CPT code selection depends on the specific procedure performed:

For Nail Removal:

• 11730: Avulsion of nail plate, partial or complete, simple; single

  • Use this when removing the entire nail plate or a significant portion
  • Covers simple nail removal procedures

• 11732: Avulsion of nail plate, partial or complete, simple; each additional nail plate (add-on code)

  • Only use if multiple nails are removed

For Drainage Only:

• 11740: Evacuation of subungual hematoma
  • Use this for trephination (drilling/burning a hole through the nail to drain blood)
  • This is the appropriate code when the nail plate is preserved and only drainage is performed 1

Clinical Decision Algorithm

Choose the procedure code based on:

1. If nail plate remains intact → Use CPT 11740 (trephination/drainage)

   • Indicated when hematoma involves <50% of nail bed
   • No nail bed laceration suspected
   • Nail plate is adherent and stable

2. If nail plate is removed → Use CPT 11730 (nail avulsion)

   • Indicated when hematoma involves >50% of nail bed
   • Suspected nail bed laceration requiring repair
   • Nail plate is already avulsed or unstable
   • Need to inspect/repair underlying nail bed

Important Coding Considerations

• External cause codes: Consider adding an external cause code (V00-Y99) to document mechanism of injury, which improves data completeness for injury surveillance 2
• Laterality is mandatory: ICD-10-CM requires specification of left vs. right
• Encounter status matters: The seventh character (A, D, or S) must be included for proper coding
• Documentation requirements: Ensure clinical documentation clearly specifies the toe involved, laterality, and presence of nail damage to support code specificity 3

Common Pitfalls to Avoid

• Don't use unspecified codes when specific information is available (e.g., S90.219A for unspecified toe) - this reduces data quality 4
• Don't confuse CPT 11740 with 11730 - they represent different procedures with different indications
• Don't omit the seventh character on the ICD-10-CM code - it's required for valid coding
• Don't forget laterality - "left" must be documented and coded