The Short Answer
Developmental milestones are skills most babies achieve by a certain age across four domains: motor (physical movement), language and communication, social and emotional, and cognitive (thinking and problem-solving). The CDC updated its milestone guidelines in 2022 to reflect what most — not just 50% — of babies achieve by each age, making them more reliable for identifying developmental concerns.
Important: Milestones describe a typical range. All babies develop at their own pace. Talk to your paediatrician if you are concerned, rather than waiting.
2 Months
Social & Emotional
- Smiles at people (social smile)
- Calms down when spoken to or picked up
Language & Communication
- Coos, makes gurgling sounds
- Turns head towards familiar voices
Motor
- Holds head up when on tummy
- Moves both arms and legs equally
Cognitive
- Watches faces closely; follows movement with eyes
4 Months
Social & Emotional
- Smiles spontaneously, especially at people
- Enjoys play; may cry when play stops
Language & Communication
- Begins to babble ("ba," "da")
- Laughs out loud
Motor
- Holds head steady without support
- Pushes up on elbows during tummy time
- Reaches for objects; may bring hands to mouth
Cognitive
- Follows moving objects with eyes across face
- Recognises familiar people from a distance
6 Months
Social & Emotional
- Knows familiar faces; may be wary of strangers
- Likes to play with others (especially parents)
Language & Communication
- Responds to sounds by making sounds
- Strings vowels together when babbling ("ah," "eh," "oh")
Motor
- Rolls over both ways (front to back, back to front)
- Sits with support; briefly sits unsupported
- Bears weight on legs when standing (with support)
Cognitive
- Begins to pass objects between hands
- Uses hands and mouth to explore objects
9 Months
Social & Emotional
- Clings to familiar adults; shows stranger anxiety
- Has favourite toys
Language & Communication
- Babbles with consonant-vowel combinations ("mama," "dada", not yet specific)
- Uses gestures (pointing, waving)
- Understands "no"
Motor
- Sits independently without support
- Crawls on hands and knees (or an alternative method)
- Pulls to standing; cruises along furniture
Cognitive
- Points at things; looks for hidden objects (object permanence begins)
- Bangs objects together
12 Months
Social & Emotional
- Shows affection (hugging, cuddling)
- Shows preference for certain people
- Has simple play preferences
Language & Communication
- Says "mama" and "dada" specifically for parents
- Uses one other word ("bye," "dog," "ball")
- Waves bye-bye; responds to simple requests
Motor
- Pulls to standing; walks holding on to furniture
- May take first independent steps (9–15 months is normal)
- Uses pincer grasp (thumb and index finger)
Cognitive
- Explores objects in different ways (dropping, banging, throwing)
- Finds hidden objects easily
15 Months
Social & Emotional
- Copies other children while playing
- Shows others objects to share interest
Language & Communication
- Uses 3 or more words
- Says "no" and shakes head
Motor
- Walks independently
- Climbs onto furniture with assistance
Cognitive
- Uses objects for their intended purpose (stirs with spoon, talks into phone)
- Stacks two blocks
18 Months
Social & Emotional
- Moves away from caregiver but checks back frequently
- Points to show something interesting
Language & Communication
- Uses at least 10 words
- Tries to say more words; repeats words overheard in conversation
Motor
- Walks well; may run (but falls often)
- Drinks from a cup; eats with a spoon (messily)
- Scribbles with crayons
Cognitive
- Knows what ordinary items (phone, brush, spoon) are for
- Pretend play begins (feeding a doll)
24 Months (2 Years)
Social & Emotional
- Plays alongside other children (parallel play)
- Shows increasing independence; may have tantrums
Language & Communication
- Uses 50+ words
- Combines two words together ("more juice," "daddy go")
- Points to objects or pictures when named
Motor
- Runs without falling often
- Kicks a ball; throws overhand
- Climbs on and off furniture alone
Cognitive
- Follows two-step instructions ("Pick up the toy and bring it to me")
- Sorts objects by shape and colour
When to Talk to Your Doctor
Contact your paediatrician if your child:
- Is not meeting multiple milestones in a given category at their checkup age
- Loses skills they previously had, this always requires prompt evaluation
- You have any concern about their development, trust your instincts
The CDC's Milestone Tracker App (free, iOS and Android) helps parents track progress and share it with their doctor.
Frequently Asked Questions
What are developmental milestones?
Developmental milestones are skills most babies and children achieve by a certain age across four domains: motor (physical movement), language and communication, social and emotional, and cognitive (thinking and problem-solving). The CDC updated its guidelines in 2022 to reflect what most — not just 50% — of children achieve by each age, making them more useful for identifying concerns.
What should a baby be doing at 6 months?
By 6 months, most babies roll both ways (front to back and back to front), sit briefly without support, bear weight on their legs, babble with vowel strings, recognise familiar faces, and show wariness of strangers. They should be using their hands and mouth to actively explore objects.
What if my baby is not meeting milestones on the chart?
Milestones describe a typical range, not an exact schedule. If your baby is close but not quite there, mention it at the next routine check. If your baby is missing multiple milestones in a domain, or if you have any concern, talk to your paediatrician rather than waiting — early intervention consistently improves outcomes.
Is it a problem if my baby skips crawling?
No — crawling is not a required milestone. Research from the AAP confirms that many healthy babies bottom-shuffle, roll, or pull straight to standing without ever crawling, and develop normally. What matters is that babies are mobile and exploring, not the specific method.
When should a baby start walking?
The normal range for independent walking is 9–15 months, with the average around 12 months. Some babies walk as early as 9 months; others not until 15–16 months. If a child is not walking by 18 months, the CDC and AAP recommend a paediatric evaluation.
What is the difference between a developmental delay and being "on the late end of normal"?
Milestones describe a range, and there is natural variation within that range. A "delay" is when a child consistently falls outside the expected window across multiple skills or domains, particularly if skills are regressing (lost abilities always warrant prompt evaluation). If your child is meeting most milestones but slightly later in one area, discuss it with your doctor — they can assess whether monitoring or referral is appropriate.
Key Sources
- CDC. Developmental Milestones (2022 Updated Guidelines)
- AAP. Developmental Milestones
- WHO. Child Growth Standards
Sources
- AAP — Developmental milestones for children
- CDC — Learn the Signs. Act Early. — milestone tracking
- WHO — Child health and development
🔧 Helpful Tools
- Baby Food Guide — Safe foods and introduction schedule for your baby
- Baby Milestones Tracker — Track your baby's developmental milestones
- All Baby Tools — Browse all free tools for pregnancy and baby care
📖 Related Articles
- When Do Babies Start Crawling? — Most babies begin crawling between 7 and 10 months of age. Learn the stages of crawling, signs your baby is ready, and when to talk to your doctor.
- Milestones: What's Normal and When Should You Check? — A complete guide to developmental milestones in babies and toddlers — what's normal, what varies, and when you should contact your pediatrician.
