Baby Milestones by Month (2–24 Months)

Watching a baby grow from a sleepy newborn into a walking, babbling toddler is one of parenting’s great joys — and a frequent source of comparison anxiety. Milestones are best understood as a map of typical ranges across four areas of development, not a scoreboard. This guide walks the CDC checkpoints month by month and, just as importantly, explains when a missed milestone is worth a conversation with your pediatrician.

The four domains of development

Development unfolds across four domains: social/emotional (bonding, smiling, playing), language/communication (cooing, babbling, words, and understanding), movement/physical (head control, rolling, sitting, crawling, walking, and grasping), and cognitive (learning, problem-solving, and exploring). Babies progress in all four, though rarely at the same pace — a strong mover may be a later talker, and that is usually normal.

Milestones from 2 to 6 months

By two months, look for a social smile, the start of cooing, and lifting the head during tummy time. By four months, babies typically smile to get attention, babble, hold their head steady, and reach for toys. By six months, many roll over, sit with support, take turns making sounds, and bring objects to their mouth to explore. These early months are about head control, social connection, and discovering cause and effect.

Milestones from 9 to 12 months

Around nine months, babies often sit without support, respond to their name, show stranger awareness, and look for a dropped object. By the first birthday, many pull to stand and cruise along furniture, say a word or two like "mama" or "dada" with meaning, wave bye-bye, play games like pat-a-cake, and put objects into a container. Crawling appears for many — though some babies skip it, which is fine.

Milestones from 15 to 24 months

By fifteen to eighteen months, expect walking well, climbing, several words, pointing to show you things, copying others, and following simple one-step directions. By two years, many run, kick a ball, use two-word phrases, point to named pictures in a book, and use toys with buttons and knobs. This stretch is defined by mobility, language growth, and budding independence.

Remember: ranges, not deadlines

Each milestone spans a window, and reaching one early or late within that window is normal. Walking, for instance, ranges widely across the end of the first year and into the second. For babies born prematurely, use corrected age (based on the due date) in the first two years, since they typically reach milestones on that adjusted timeline. Resist comparing your baby to others — the range is wide for good reason.

When to talk to your pediatrician

Act early when it counts. Raise it with your pediatrician if your baby misses several milestones for their age, loses skills they once had, does not respond to sounds or make eye contact, or if your instincts say something is off. Early identification and support — including services like early intervention — are most effective when started promptly, so trust your observations and ask.

How to support development

The most powerful tools are free and everyday: talk, read, and sing to your baby constantly; offer daily tummy time; respond warmly to their cues; give them safe space and simple objects to explore; and limit screens (the AAP advises avoiding screen media other than video chat before roughly eighteen to twenty-four months). Track progress with our milestone tracker, and bring any questions to well-child visits.