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F51.3

F51.3Sleepwalking [somnambulism]

Billable / specific codeICD-10-CM

F51.3 is a billable, specific ICD-10-CM code for sleepwalking [somnambulism]. It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Non-rapid eye movement sleep arousal disorders, sleepwalking type

Risk adjustment

F51.3 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

F51.3 is named in 16 Medicare coverage policies 14 listing it as supporting medical necessity, and 2 listing it as NOT covered. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A52434Health and Behavior Assessment/Intervention – Medical Policy Articlenot covered
  • A56865Billing and Coding: Psychiatric Inpatient Hospitalizationnot covered
  • A56903Billing and Coding: Polysomnography and Other Sleep Studies
  • A56923Billing and Coding: Outpatient Sleep Studies

How F51.3 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to F51.3.

  • Somnambulism
  • Insomnialearned
  • Sleepwalking
  • Walkingsleep
  • Disordernon-rapid eye movement sleep arousalsleepwalking type
  • Disordersleepwalking

Related codes at this level

Codes that share F51. If F51.3 is not quite right, the correct code is usually one of these.

Questions about F51.3

Is F51.3 a billable ICD-10-CM code?
Yes. F51.3 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does F51.3 sit in the tabular list?
Mental, Behavioral and Neurodevelopmental disorders (F01-F99), in the block Behavioral syndromes associated with physiological disturbances and physical factors (F50-F59).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.