Key takeaways: By 9 months, most babies show stranger awareness, babble “mamama,” sit without support, and look for dropped objects. By 12 months, most wave, say “mama” or “dada,” pull to stand, and use a pincer grasp. Walking alone often comes later, and that’s okay.
The second half of the first year is full of big changes: sitting, crawling, pulling up, and first words. Here’s what to look for.
Milestones by 9 Months
Social and emotional:
- Is shy, clingy, or fearful around strangers.
- Shows several facial expressions, like happy, sad, angry, and surprised.
- Looks when you call their name.
- Reacts when you leave (looks, reaches for you, or cries).
- Smiles or laughs when you play peekaboo.
Language and communication:
- Makes different sounds like “mamamama” and “babababa.”
- Lifts arms up to be picked up.
Cognitive:
- Looks for objects when dropped out of sight.
- Bangs two things together.
Movement and physical:
- Gets to a sitting position by themselves.
- Moves things from one hand to the other.
- Uses fingers to “rake” food toward themselves.
- Sits without support.
Milestones by 12 Months
Social and emotional:
- Plays games with you, like pat-a-cake.
Language and communication:
- Waves “bye-bye.”
- Calls a parent “mama” or “dada” or another special name.
- Understands “no” (pauses briefly or stops when you say it).
Cognitive:
- Puts something in a container, like a block in a cup.
- Looks for things they see you hide, like a toy under a blanket.
Movement and physical:
- Pulls up to stand.
- Walks, holding on to furniture.
- Drinks from a cup without a lid, as you hold it.
- Picks things up between thumb and pointer finger.
What About Walking and Crawling?
Crawling isn’t on the CDC checklist because many healthy babies skip it. Walking alone usually starts between about 9 and 18 months. The CDC lists “takes a few steps on their own” at 15 months.
How to Support Development
- Name everything your baby looks at or points to.
- Play peekaboo and hide-and-seek with toys.
- Read together every day.
- Encourage gestures: wave, clap, and point together.
- Offer safe spaces to crawl, cruise, and climb.
- Offer finger foods to practice the pincer grasp.
- Respond to babbling as if it’s conversation.
Developmental Screening at 9 Months
The AAP recommends formal developmental screening at 9, 18, and 30 months, plus autism-specific screening at 18 and 24 months. You may be asked to fill out a questionnaire.
When to Talk to Your Doctor
At 9 months, if your baby:
- Doesn’t bear weight on legs with support.
- Doesn’t sit with help.
- Doesn’t babble.
- Doesn’t play back-and-forth games.
- Doesn’t respond to their own name.
- Doesn’t seem to recognize familiar people.
- Doesn’t look where you point.
At 12 months, if your baby:
- Doesn’t crawl or move around in some way.
- Can’t stand when supported.
- Doesn’t search for things they see you hide.
- Doesn’t say single words like “mama” or “dada.”
- Doesn’t use gestures like waving or shaking the head.
- Doesn’t point to things.
At any age: loss of skills, or any concern.
The Bottom Line
From 9 to 12 months, babies become explorers and communicators. Support them with play, talk, and safe spaces to move, and talk to your doctor early about any concerns.
Want more support for your baby’s first year? My book, From First Breath to First Birthday, is available on Amazon.
Sources
- Centers for Disease Control and Prevention. Learn the Signs. Act Early.: Milestones by 9 Months; Milestones by 1 Year; Milestones by 15 Months. https://www.cdc.gov/milestones
- Zubler JM, Wiggins LD, Macias MM, et al. Evidence-informed milestones for developmental surveillance tools. Pediatrics. 2022;149(3):e2021052138.
- Lipkin PH, Macias MM; Council on Children With Disabilities, Section on Developmental and Behavioral Pediatrics. Promoting optimal development: identifying infants and young children with developmental disorders through developmental surveillance and screening. Pediatrics. 2020;145(1):e20193449.
- Hyman SL, Levy SE, Myers SM; Council on Children With Disabilities, Section on Developmental and Behavioral Pediatrics. Identification, evaluation, and management of children with autism spectrum disorder. Pediatrics. 2020;145(1):e20193447.
- WHO Multicentre Growth Reference Study Group. WHO Motor Development Study: windows of achievement for six gross motor development milestones. Acta Paediatr Suppl. 2006;450:86-95.
This article is for general education and is not a substitute for individualized medical advice. Always talk with your baby’s health care provider or your own provider about your specific situation. If you think your baby or you may have a medical emergency, call 911.
