What if My Baby Missed a Milestone?

Evidence-based guidance on what it means, when to worry, and what to do next.

Key takeaways

  • Milestone ranges are averages — healthy children develop at different rates
  • Missing one milestone is usually not a concern; missing multiple may warrant evaluation
  • Premature babies should be assessed using adjusted age until age 2
  • Early intervention (before age 3) produces the best outcomes for developmental delays
  • You can contact your state's early intervention program directly — no referral needed
  • Loss of previously acquired skills at any age requires immediate evaluation

Content reviewed against published CDC, AAP guidelines

Last reviewed: July 2026 · Editorial policy

Last reviewed:

Understanding milestone ranges

Developmental milestones represent skills that most children achieve by a certain age. The CDC updated its milestone checklist in 2022 to reflect skills that 75% of children reach by each age — meaning 25% of typically developing children have not yet reached that milestone at the listed age.

A “missed” milestone does not automatically mean something is wrong. However, it is a signal to pay attention and, in some cases, seek evaluation. The key factors are:

  • How far behind the expected range the child is
  • Whether delays exist in multiple developmental areas
  • Whether the child is making progress (even if slowly)
  • Whether the child has lost skills they previously had

When to talk to your pediatrician

Contact your pediatrician if your child:

  • Is more than 2-3 months behind on a motor milestone
  • Shows delays in two or more developmental areas (motor, language, social, cognitive)
  • Has lost skills they previously had (regression)
  • Shows no progress over a 2-3 month period
  • Has risk factors such as prematurity, low birth weight, or family history of developmental conditions

You do not need to wait for the next well-child visit. Call your pediatrician to discuss your observations, or contact your state's early intervention program directly.

Factors that affect milestone timing

Several factors can influence when a child reaches milestones:

  • Prematurity: Use adjusted age until age 2
  • Temperament: Some children are cautious and take longer to attempt new skills
  • Opportunity: Children need practice time (e.g., tummy time for rolling)
  • Birth order: Later-born children sometimes reach milestones at slightly different rates
  • Individual variation: Some children focus on one area (e.g., language) before another (e.g., motor)

Early intervention: what it is and how to access it

Early intervention is a system of services for infants and toddlers (birth to 3) with developmental delays or disabilities. Under the Individuals with Disabilities Education Act (IDEA) Part C, every US state provides these services free of charge.

Services may include:

  • Physical therapy (for motor delays)
  • Speech-language therapy (for communication delays)
  • Occupational therapy (for feeding or fine motor difficulties)
  • Developmental therapy (for cognitive or play skills)
  • Family training and counseling

You can self-refer — no doctor's referral is required. Contact your state's early intervention program or ask your pediatrician for a referral.

Guides by specific milestone concern

6 moNot Rolling at 6 Months9 moNot Babbling at 9 Months9 moNot Sitting at 9 Months12 moNot Crawling at 12 Months12 moNo Words at 12 Months12 moNot Pointing at 12 Months15 moNot Walking at 15 Months18 moNot Walking at 18 Months18 moNo Words at 18 Months9-12 moNot Responding to Name24 moNo Two-Word Phrases at 2 YearsComparisonEarly vs Late Walkers

Frequently asked questions

Is it normal for babies to miss milestones?
Yes. Milestone ranges are averages, and healthy children develop at different rates. Missing one milestone does not mean there is a problem. However, missing multiple milestones or showing no progress over several months warrants a conversation with your pediatrician.
What should I do if my baby missed a milestone?
First, note the specific milestone and how far behind your child is. Many children catch up on their own. If the delay is more than 2-3 months or involves multiple areas, contact your pediatrician or your state's early intervention program for a free evaluation.
Does missing a milestone mean my child has autism?
No. Missing a milestone alone does not indicate autism. Autism involves a pattern of differences across social communication and behavior. Many typically developing children are late in reaching one or more milestones.
Can early intervention help if my child is behind?
Yes. Research consistently shows that early intervention (before age 3) produces the best outcomes for children with developmental delays. Services are free in every US state through the IDEA Part C program.
Do premature babies reach milestones later?
Yes. Premature babies should be evaluated using their adjusted age (chronological age minus weeks of prematurity) until age 2. A baby born 2 months early is expected to reach milestones about 2 months later than full-term peers.

Bottom line

Missing a milestone does not mean something is wrong — but it does mean you should pay attention. If your child is more than 2-3 months behind, shows delays in multiple areas, or has lost previously acquired skills, contact your pediatrician or your state's early intervention program for a free evaluation. Early intervention produces the best outcomes when started before age 3.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.

All content follows our editorial policy and is reviewed against published clinical guidelines.

2,705 evidence-based guides6 authoritative medical sources

Milestones by AgeDevelopmental Red FlagsEarly Intervention Guide