Baby & Toddler Milestone Checker

Developmental milestones are skills or behaviours that most children achieve by a certain age — such as smiling, rolling over, saying first words, or walking. They're divided into four domains: social/emotional, language/communication, cognitive (thinking and learning), and motor (movement). The CDC's 2022 updated checklist reflects what 75–90% of children can do at each age checkpoint.

Not necessarily — all children develop at slightly different rates, and milestones are meant as ranges, not strict deadlines. However, if your child is significantly behind on multiple milestones, or if you've noticed a loss of skills they previously had, it's worth mentioning to your pediatrician. Early intervention, when needed, leads to dramatically better outcomes.

The 2022 CDC revision was a significant change. The previous list described milestones that 50% of children achieved by a given age — which meant half of all typically-developing children weren't meeting the listed milestones. The updated list reflects skills that 75–90% of children achieve, meaning they're more reliable as universal checkpoints. Several milestones were moved to later ages to reflect this change.

Typical development means following a general sequence more than a strict timeline. A baby will almost always sit before they stand, stand before they walk — but the age at which each step happens varies considerably. Premature babies are assessed using their corrected age (adjusted for how early they were born) until at least age 2. Children with older siblings often develop language earlier. Those who walk at 18 months are just as typical as those who walk at 10 months.

Talk to your pediatrician. Bring a list of any milestones your child isn't meeting. Your doctor may do a developmental screening (like the M-CHAT for autism, or the ASQ) and can refer you to early intervention services if needed. In the US, children under 3 with developmental concerns are eligible for free evaluation and services through the Early Intervention program (IDEA Part C). For ages 3+, school districts provide evaluations under IDEA Part B.

No. A checklist like this one helps you track and notice potential concerns, but it's not a formal screening tool. A developmental screening (like the Ages & Stages Questionnaires / ASQ, or the M-CHAT-R for autism) is a validated questionnaire administered by or with your child's doctor and provides a more standardised assessment. The CDC recommends formal developmental screening at 9, 18, and 30 months, and autism-specific screening at 18 and 24 months.