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ICD-10-CM 2027 diagnosis code

F40.21Animal type phobia

Not billable — use a more specific code

F40.21 is a header code, so it can't be reported by itself. Choose one of the 2 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About F40.21

F40.21 is the ICD-10-CM diagnosis code for animal type phobia. It belongs to category F40 (phobic anxiety disorders), block F40-F48 (anxiety, dissociative, stress-related, somatoform and other nonpsychotic mental disorders) and chapter 5 (mental, Behavioral and Neurodevelopmental disorders). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.

Within F40.2 (specific (isolated) phobias), F40.21 is specifically for animal type phobia. Related codes cover natural environment type phobia (F40.22), blood, injection, injury type phobia (F40.23), situational type phobia (F40.24) and other specified phobia (F40.29).

To report this condition, pick the subcode that matches the documentation: F40.210 (Arachnophobia) and F40.218 (phobia).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under F40.21

Notes that apply from higher levels

Instructions written at a parent level also apply to F40.21.

› From F40.2 Specific (isolated) phobias
Excludes2

Broader instructions also apply from Chapter 5: Mental, Behavioral and Neurodevelopmental disorders.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about F40.21

Is F40.21 billable?

No. F40.21 is a header code. Report one of its more specific subcodes instead.