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ICD-10-CM 2027 diagnosis code

F40.240Claustrophobia

✓ Billable / specific

F40.240 is a valid, billable ICD-10-CM code for claustrophobia. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Claustrophobia.

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 F40.240

F40.240 is the ICD-10-CM diagnosis code for Claustrophobia. 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 billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within F40.24 (situational type phobia), F40.240 is specifically for Claustrophobia. Related codes cover Acrophobia (F40.241), fear of bridges (F40.242), fear of flying (F40.243) and other situational type phobia (F40.248).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 882 (Neuroses Except Depressive, relative weight 0.9952), in MDC 19 (Mental Diseases and Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

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

Before ICD-10, this condition was coded in ICD-9-CM as 300.29 (other isolated or specific phobias).

Notes that apply from higher levels

Instructions written at a parent level also apply to F40.240.

› From F40.2 Specific (isolated) phobias
Excludes2

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

Alphabetic index entries

2 entries

Terms in the official ICD-10-CM index that lead to F40.240.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

MDC 19 · Mental Diseases and Disorders

ICD-9-CM equivalent

Converter →
  • 300.29Other isolated or specific phobiasapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

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 F40.240

Is F40.240 billable?

Yes. F40.240 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can F40.240 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict F40.240 as a principal diagnosis.

Is F40.240 a CC or MCC?

No. F40.240 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does F40.240 group to?

F40.240 is used in the MS-DRG v44.0 logic for MS-DRG 882 (Neuroses Except Depressive). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for F40.240?

The CMS General Equivalence Mappings map F40.240 to ICD-9-CM 300.29.