36 Months (3 Years) Milestones

Three-year-olds are wonderful, frustrating, hilarious, and exhausting -- often all in the same five minutes. They are building the foundations for school readiness: language, social skills, self-control, and curiosity. If you have concerns, trust your instincts. You know your child best, and early support makes a real difference. There is no downside to asking your doctor about something that worries you.

Runs Well

CDC WHO

Your child runs smoothly with good coordination and can stop and change direction.

What it looks like

They run with a natural-looking gait, arms swinging. They can stop on purpose, change direction, and run around obstacles without falling. They still trip sometimes -- all kids do.

Typical range

2 yr 2 moavg 2 yr 8 mo3 yr3 yr 4 mo

When should I worry?

This is normal

By 3, most children run with confidence. Some are natural sprinters while others prefer a careful pace. Both styles are normal -- not every child wants to race.

Mention at next visit

If by 40 months your child still runs very awkwardly, falls frequently, or seems significantly less coordinated than peers, bring it up at your next visit.

Call your doctor

If your child was running well and has suddenly developed difficulty with coordination, limping, or weakness, contact your pediatrician.

Pedals a Tricycle

CDC

Your child can pedal a tricycle or similar ride-on toy.

What it looks like

They sit on a tricycle and push the pedals to move forward. Steering is still wobbly, but they can make it go. Some kids prefer balance bikes, and that's equally great.

Typical range

2 yr 4 moavg 2 yr 10 mo3 yr 4 mo3 yr 6 mo

When should I worry?

This is normal

Pedaling is a complex skill -- the feet go in circles while the hands steer. Many kids get it around 3, but some don't master it until closer to 4. Practice and opportunity matter a lot.

Mention at next visit

If by 42 months your child can't coordinate pedaling at all, or has difficulty with other activities that require alternating leg movements, mention it to your doctor.

Call your doctor

If your child has new difficulty with leg coordination or seems to have weakness on one side, contact your pediatrician.

Climbs Stairs Alternating Feet

CDC

Your child walks up stairs using one foot per step, like an adult, instead of both feet on each step.

What it looks like

Going upstairs, they put the left foot on one step, then the right foot on the next -- alternating feet. They may still need to hold the railing. Going down may still be two feet per step.

Typical range

2 yr 4 moavg 2 yr 10 mo3 yr 4 mo3 yr 6 mo

When should I worry?

This is normal

Alternating feet on stairs requires balance and confidence. Most kids can do it going up by 3, but going down takes longer. Using a railing is smart, not a sign of delay.

Mention at next visit

If by 42 months your child still puts both feet on every step going up, or avoids stairs entirely, mention it to your pediatrician.

Call your doctor

If your child has lost the ability to climb stairs or shows sudden changes in coordination, contact your doctor.

When to Talk to Your Doctor

Red flags to watch for

If you notice any of the following, contact your pediatrician. These signs do not necessarily mean something is wrong, but they are worth discussing with a professional.

Falls down a lot or has trouble with stairs
What to do
Mention this to your pediatrician. They may want to evaluate muscle tone and coordination.
Drools or has very unclear speech
What to do
Talk to your pediatrician about a speech-language evaluation. Speech therapy can help enormously at this age.
Cannot work simple toys (shape sorters, simple puzzles, turning handles)
What to do
Bring this up at your next visit. It could indicate a need for fine motor or cognitive evaluation.
Does not speak in sentences
What to do
Talk to your pediatrician about a speech evaluation. By 3, most children use sentences.
Does not understand simple instructions
What to do
Discuss with your doctor. Hearing should be checked, and a developmental evaluation may be helpful.
Does not engage in pretend play
What to do
Mention this to your pediatrician. Pretend play is an important milestone by age 3.
Does not want to play with other children or with toys
What to do
Talk to your doctor about this. Social engagement is important for development.
Does not make eye contact
What to do
Contact your pediatrician. This can be evaluated as part of a developmental screening.
Loses skills they once had
What to do
Contact your pediatrician promptly. Loss of skills always warrants evaluation, regardless of age.