Selective Mutism
ICD-11 Classification of Selective Mutism (6B06)
In ICD-11-MMS, Selective Mutism is coded 6B06 and classified within Anxiety or fear-related disorders — reframing it as an anxiety-driven condition marked by consistent failure to speak in specific social settings despite normal speech elsewhere.
When a child speaks freely at home yet falls silent at school, the right code anchors the right care pathway.
In short
In the ICD-11 for Mortality and Morbidity Statistics (ICD-11-MMS), Selective Mutism is classified under code 6B06. It sits within the grouping of Anxiety or fear-related disorders, reflecting the contemporary understanding of selective mutism as anxiety-driven rather than a primary disorder of speech or oppositionality. The defining feature is a consistent failure to speak in specific social situations where speech is expected (typically school), despite speaking normally in other settings.The classification, briefly
Under ICD-11, 6B06 Selective mutism is characterised by a marked, persistent selectivity in speaking — fluent expressive language in familiar contexts (usually the home) contrasted with consistent silence in defined social situations. For the diagnosis to hold, the disturbance should persist for at least one month (beyond the first month of school), is not attributable to a lack of knowledge of the spoken language required, and is not better accounted for by a communication disorder, an autism spectrum disorder, schizophrenia or another condition. Its placement among anxiety or fear-related disorders is the substantive shift from earlier nosology, which had located it among disorders with onset in childhood. This reframing is clinically meaningful: it directs assessment toward the child's social anxiety profile and away from interpreting silence as defiance or a speech impairment.Clinical note
Differentiate from a transient adjustment reaction (e.g. the first weeks at a new school or post-migration silent period), from a primary speech-language disorder, and from autism spectrum disorder where the communication pattern is pervasive rather than situation-bound. Co-occurring social anxiety is common and warrants direct enquiry. Hearing should be confirmed intact.The Pinnacle way
A clinical AbilityScore® and any formal diagnosis are established only at a Pinnacle Blooms Network centre, under qualified clinician care — never from a code lookup or an online form. Coding orients the pathway; structured clinician assessment determines it. Explore our speech and language therapy pathway, understand how the AbilityScore is formed, or [begin with us](/).Trusted sources
WHO ICD-11 for Mortality and Morbidity Statistics — Selective mutism (6B06), within Anxiety or fear-related disorders.Next step — For a child showing situation-specific silence, refer for a structured developmental and anxiety assessment at a Pinnacle Blooms Network centre.
This is general information, not a diagnosis — a clinical AbilityScore® and any diagnosis are formed only at a Pinnacle Blooms Network centre under qualified clinician care.
What to watch
Consistent failure to speak in specific settings (typically school) lasting beyond a month, alongside fluent speech at home; watch for co-occurring social anxiety and rule out hearing loss or a primary language disorder.
Try this at home
For a clinician: code as 6B06 only after confirming the silence is situation-bound, persistent beyond one month, and not better explained by ASD, a communication disorder or limited language knowledge.
Trusted sources
Developed by SETU Consortium · Pinnacle Blooms Network · Last reviewed 2026-06-10 · reviewed every 365 days
This is general information, not a diagnosis. A clinical AbilityScore® and any diagnosis are formed only at a Pinnacle Blooms Network centre, under qualified clinician care.
Frequently asked
What is the ICD-11 code for Selective Mutism?
Selective Mutism is classified under code 6B06 in the ICD-11 for Mortality and Morbidity Statistics (ICD-11-MMS).
Where does Selective Mutism sit within ICD-11?
It is grouped under Anxiety or fear-related disorders, reflecting the understanding of selective mutism as anxiety-driven rather than a primary speech or behavioural disorder.
How long must symptoms persist for the diagnosis?
The selectivity in speaking should persist for at least one month, not counting the first month of school, and must not be attributable to limited knowledge of the required spoken language.
How does ICD-11 distinguish selective mutism from autism?
In selective mutism, communication is fluent in familiar settings and the silence is situation-bound; in autism spectrum disorder the social-communication differences are pervasive across settings. The diagnosis is not made if the pattern is better explained by ASD.