If the source concept asserts an age or phase of life for onset of the disorder, a target will be selected first including the restriction or, if none is available, then a more general classification target (mapCategoryId="Properly classified", mapRule =TRUE, mapAdvice=NULL) that is inclusive of the source concept. No mapRule restrictions for age will be applied in cases where there is a properly classified ICD-10 Map target. If the authoritative sources include specifications for employment of age, those will be used. Otherwise, these definitions for common phases of life will be employed:

• "Neonatal": birth to completion of 28 days of life
• "Perinatal": 22 weeks of gestation to completion of 7 days of life
• "Childhood": birth until 19^th birthday
• "Adult": 19^th birthday until death
• "Infant (infancy)": birth until 2^nd birthday
• "Juvenile": 2^nd birthday until 19^th birthday
• "Adolescence": 12^th birthday until 19^th birthday
• "Pre-senile": birth until 65^th birthday
• "Senile": 65^th birthday onwards

If the source concept does not assert age or time of life and only restricted targets are within scope, the map will be considered CONTEXT DEPENDENT and the Map Terminologist will assemble two or more Map members including Map Rules to properly classify to each ICD-10 target classification. 

Exemplar: Age: #1

• 32398004 | Bronchitis (disorder)| will be flagged for age context using the Age of Onset map rule, because WHO advises that Bronchitis (without further specification) should map to J20.9, Acute bronchitis, for a patient under age 15, and map to J40, Bronchitis not specified as chronic or acute, for patients above this age.