Backed by pediatric research
What to expect, what to watch for, and what to do — from birth through age 3. Written by a parent who read the research so you don't have to.
For educational purposes only. Every child develops at their own pace. Consult your pediatrician with any concerns.
Scout by FamilyForce
Scout sends you a monthly email + calendar invite timed to your baby's exact age. You'll know what milestones are opening, which ones are closing, and exactly what to do about it — before the window closes.
Try Scout Free →Browse by month
Head lifting, recognizing your face, and the first hints of a smile. What's happening in your newborn's brain right now.
Read guide → 2 MonthsThe first real smile meant just for you. At 2 months, your baby is also tracking objects and starting to coo.
Read guide → 3 MonthsRolling is on the horizon. Three months is when tummy time becomes non-negotiable and swaddling starts to phase out.
Read guide → 4 MonthsThe 4-month sleep regression is real, and most parents aren't ready for it. Here's what's happening and what actually helps.
Read guide → 5 MonthsSigns of solid food readiness start appearing now. Most pediatricians say wait until 6 months — but the prep starts at 5.
Read guide → 6 MonthsThe biggest nutritional shift of the first year. At 6 months, your baby is ready for solid food, and sitting with support.
Read guide → 7 MonthsMobility prep goes into overdrive. Rocking on all fours, grabbing everything, and a new awareness of when you've left the room.
Read guide → 8 MonthsMost babies crawl by 8–10 months and the texture window closes at 9. Here's what to act on before it's too late.
Read guide → 9 MonthsSeparation anxiety officially arrives at 9 months. Here's why it happens, what it means, and what actually helps.
Read guide → 10 MonthsCruising the furniture, a cup deadline before 12 months, and first words just weeks away.
Read guide → 11 MonthsFirst words are forming and the peanut allergy prevention window closes this month. Here's what needs your attention.
Read guide → 12 MonthsFirst steps, first words, and the developmental checklist every parent should know before the one-year visit.
Read guide → 13 MonthsMonth 13 is the transition month. Formula is over, whole milk starts, and walking is consolidating.
Read guide → 14 MonthsWalking is fully established and the first signs of pretend play are starting — which matters more than you'd expect.
Read guide → 15 MonthsWalking assessed, 10-word language count, pointing, and the bottle deadline. Here's what to say and what to bring.
Read guide → 16 MonthsThe first real tantrums arrive around 15–18 months. They're neurological, not behavioral — here's what actually helps.
Read guide → 17 MonthsPretend play peaks around 17 months and predicts language, creativity, and emotional regulation at school age.
Read guide → 18 MonthsThe first formal autism screening happens at 18 months. Here's what the M-CHAT tests and how to prepare.
Read guide → 19 MonthsTwo-word phrases mark a qualitative leap in language — not just more words, but the beginning of constructed meaning.
Read guide → 20 Months30–50+ words and a fierce independence drive. Here's what's behind the "I do it" phase and what to do about it.
Read guide → 21 MonthsPronoun use begins around 21–27 months and is a bigger cognitive leap than it looks.
Read guide → 22 MonthsThe two-year visit is two months out. Here's the checklist, the language count, and what to prepare.
Read guide → 23 MonthsThe 24-month visit is one month away. Here's the complete checklist and what to bring.
Read guide → 24 Months50 words, two-word combinations, second M-CHAT, and the most comprehensive developmental assessment since birth.
Read guide → 25 MonthsThree-word sentences mark real grammar, not just more vocabulary. Here's what's happening and the potty training readiness window.
Read guide → 26 MonthsReal playing together — shared rules, turn-taking, common goals — starts emerging around 24–27 months.
Read guide → 27 MonthsPronouns should be consistent by now and imaginative play is becoming rich and multi-step.
Read guide → 28 MonthsPotty training is hitting its stride — or its wall. Fine motor is becoming more precise. Here's what's developing.
Read guide → 29 MonthsThe 30-month visit was specifically added to the AAP schedule to catch language delays. Here's the full prep checklist.
Read guide → 30 MonthsThe 30-month well-child visit is the one the AAP added specifically to catch language delays between ages 2 and 3.
Read guide → 31 MonthsConsistent daytime dryness is achieved between 24–33 months. Here's where 31 months fits and what to do if training is stalling.
Read guide → 32 MonthsFour-word sentences are standard, strangers can understand most of what your child says, and narrative — recounting events — is starting.
Read guide → 33 MonthsThe 36-month visit is the most comprehensive since infancy. Here's the full checklist of what will be assessed.
Read guide → 34 MonthsLanguage is approaching full fluency, real friendships are forming, and play has genuine complexity.
Read guide → 35 MonthsThe 36-month visit is one month away — the final intensive developmental checkpoint. Here's the complete prep checklist.
Read guide → 36 MonthsThe finish line of the most intensively monitored developmental period in human life. Here's the full assessment guide.
Read guide →What are baby milestones?
Baby milestones are developmental skills and behaviors that most children acquire within predictable age ranges — from lifting their head at 2 months to walking at 12 months to forming sentences at 24 months. They span five domains: motor, cognitive, language, social-emotional, and nutritional readiness. Milestones are guides, not deadlines — a window of several weeks or months is normal for most skills.
What should I do if my baby is missing a milestone?
Missing a single milestone doesn't mean something is wrong. Development is uneven — a baby may be ahead in language and behind in motor. But if your baby is consistently behind across multiple milestones in the same domain, mention it at your next pediatrician visit. Earlier is always better when it comes to developmental evaluation. The AAP recommends screenings at 9, 18, and 30 months because early intervention produces measurably better outcomes.
When should I be worried about my baby's development?
Bring up developmental concerns at any pediatrician visit — you don't need to wait for a scheduled screening. Key flags: no smiling by 3 months, no babbling by 6 months, no pointing or waving by 12 months, no words by 16 months, or loss of previously acquired skills at any age. Loss of skills is the most urgent flag — if your baby could do something and stopped, mention it immediately.
Are baby milestone charts accurate?
Milestone charts give ranges, not exact dates — and the ranges matter. When a chart says a baby should walk at "12 months," the research shows most babies walk between 10 and 15 months, with some healthy children walking at 16–17 months. FamilyForce's milestone content cites the actual research ranges and explains what the windows mean, not just the headline age.
How do I know what milestone my baby should be hitting right now?
Browse the month-by-month guides above, or use Scout — FamilyForce's monthly email that sends you exactly the milestones that are opening, peaking, and closing for your baby's current age. It arrives on your baby's monthly birthday with a calendar invite so you never miss a window.