Important Milestones: Your Baby By Four Months
How your child plays, learns, speaks, acts, and moves offers important clues about your child’s development. Developmental milestones are things most children can do by a certain age.
Check the milestones your child has reached by the end of 4 months by completing a checklist with CDC’s free Milestone Tracker mobile app, for iOSexternal icon and Androidexternal icon devices, or by printing the checklist pdf icon[315 KB, 2 Pages, Print Only] below. Take the checklist with you and talk with your child’s doctor at every visit about the milestones your child has reached and what to expect next.
What most babies do by this age:
Social and Emotional
- Smiles spontaneously, especially at people
- Likes to play with people and might cry when playing stops
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- Copies some movements and facial expressions, like smiling or frowning
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Language/Communication
- Begins to babble
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- Babbles with expression and copies sounds he hears
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- Cries in different ways to show hunger, pain, or being tired
Print Milestone Checklist

English pdf icon[315 KB, 2 Pages, Print Only]
Spanish pdf icon[903 KB, 2 Pages, Print Only]
Cognitive (learning, thinking, problem-solving)
- Lets you know if he is happy or sad
- Responds to affection
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- Reaches for toy with one hand
- Uses hands and eyes together, such as seeing a toy and reaching for it
- Follows moving things with eyes from side to side
- Watches faces closely
- Recognizes familiar people and things at a distance
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Movement/Physical Development
- Holds head steady, unsupported
- Pushes down on legs when feet are on a hard surface
- May be able to roll over from tummy to back
- Can hold a toy and shake it and swing at dangling toys
- Brings hands to mouth
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- When lying on stomach, pushes up to elbows
- Doesn’t watch things as they move
- Doesn’t smile at people
- Can’t hold head steady
- Doesn’t coo or make sounds
- Doesn’t bring things to mouth
- Doesn’t push down with legs when feet are placed on a hard surface
- Has trouble moving one or both eyes in all directions
Tell your child’s doctor or nurse if you notice any of these signs of possible developmental delay for this age and ask for a developmental screening. Talk with someone in your community who is familiar with services for young children in your area, such as your state’s public early intervention program. For more information, visit our “If You’re Concerned” web page or call 1-800-CDC-INFO.
The American Academy of Pediatrics recommends that children be screened for general development using standardized, validated tools at 9, 18, and 30 months and for autism at 18 and 24 months or whenever a parent or provider has a concern. Ask your child’s doctor about your child’s developmental screening.
“Learn the Signs. Act Early.” materials are not a substitute for standardized, validated developmental screening tools pdf icon[918 KB, 115 Pages, Print Only].
Adapted from CARING FOR YOUR BABY AND YOUNG CHILD: BIRTH TO AGE 5, Fifth Edition, edited by Steven Shelov and Tanya Remer Altmann © 1991, 1993, 1998, 2004, 2009 by the American Academy of Pediatrics and BRIGHT FUTURES: GUIDELINES FOR HEALTH SUPERVISION OF INFANTS, CHILDREN, AND ADOLESCENTS, Third Edition, edited by Joseph Hagan, Jr., Judith S. Shaw, and Paula M. Duncan, 2008, Elk Grove Village, IL: American Academy of Pediatrics.