When do children usually grow out of separation anxiety?

What the evidence says

Separation anxiety is a normal part of development, not something to 'grow out of' on a strict schedule. It typically begins around 6 to 9 months old (sometimes as early as 4-5 months), often peaks between 10 and 18 months, and gradually eases by around age 3 as children understand that a parent leaving is temporary and gain confidence in their own independence.

A large longitudinal study following children from 18 months to school age found that most toddlers with high separation anxiety at 18 months improved on their own by age 4-5. Only a smaller group whose anxiety stayed high over time needed closer attention, since persistent anxiety can sometimes signal separation anxiety disorder rather than the normal phase.

Every child's timeline looks a bit different some toddlers barely show separation anxiety, while others feel anxious well into the preschool years, and both patterns are considered within the range of normal.

It becomes a concern, not just a phase, when the distress is much more intense than expected for the child's age, lasts most days for four weeks or more, and starts interfering with school, sleepovers, or other everyday activities. If that's happening, it's worth talking with your pediatrician.