My baby said a word and then stopped saying it. Is that normal?

Regression — losing a previously acquired skill — is always worth mentioning to the pediatrician. A single word disappearing briefly during illness is usually not a sign of a problem, but sustained loss of language skills is a red flag that warrants evaluation.

Infant Developmental Milestones: What to Expect and When to Ask Questions

The internet will tell you that a typical six-month-old sits independently, reaches for objects with both hands, babbles consonant sounds, and recognizes their name. What the internet will not tell you is that the range of “typical” is enormous, and that a baby who hits the sitting milestone at five months is not more advanced than one who hits it at eight months in any way that matters long-term.

Developmental milestones are guideposts, not report cards. Their purpose is to help pediatricians and parents identify when a child might benefit from early evaluation and intervention — not to generate anxiety about where a child sits on the percentile chart relative to a neighbor’s baby. Used correctly, milestone information leads to earlier identification of developmental differences that respond well to early therapy. Used incorrectly, it becomes a source of constant comparison that does not serve anyone.

This guide follows the CDC’s updated 2022 developmental milestone checklist — a significant revision from the previous version that changed the thresholds at which certain skills are expected. The 2022 revision was designed to make it more likely that delays would be identified and referred for evaluation earlier.

What “milestone” means: typical range vs. red flags

Most milestones have a range — an age at which most children have acquired a skill, and an outer limit at which absence of the skill warrants evaluation. The CDC’s 2022 checklist presents milestones as things “most children” can do by a specific age, chosen such that 75% of children have the skill by that age. This is different from the old 50th-percentile approach, and it is stricter — meaning more children will be flagged for evaluation. The intent is to catch delays earlier, when intervention is most effective.

A “red flag” — a sign that warrants prompt evaluation rather than wait-and-see — is different from a missed milestone. Red flags are losses of previously acquired skills, absence of specific critical skills, or patterns that suggest a particular developmental concern. Red flags warrant evaluation regardless of age.

Universal red flags at any age:

Loss of previously acquired skills (any regression in language, motor, or social function)
No response to name being called by 9 months
No babbling by 12 months
No gesturing (pointing, waving) by 12 months
No words by 16 months
No two-word phrases by 24 months

Regression — a child who was doing something and stops — always warrants a call to the pediatrician, even if the regression is temporary. Temporary regression during illness or major life changes is common; sustained regression is not.

Month by month: the first year

2 months

Most children by 2 months:

Calm down when picked up or talked to
Look at the caregiver’s face
Follow a moving object with their eyes from side to side
Hold their head up briefly when on their tummy
Make sounds other than crying — cooing

By 2 months, most infants have lost the newborn startle to sound that was present at birth; if there is no response to sound at all (no blinking, no startle, no head turn) mention it to the pediatrician.

4 months

Most children by 4 months:

Smile spontaneously in response to faces or voices
Laugh
Hold their head steady without support
Push up onto forearms during tummy time
Reach for objects with one hand
Coo and babble back and forth with a caregiver

If a 4-month-old is not smiling at faces, is not making sounds, or has significantly limited eye contact, these are worth raising with the pediatrician at the 4-month well visit.

6 months

Most children by 6 months:

Recognize familiar faces
Take turns making sounds with a caregiver
Blow raspberries
Roll from tummy to back
Reach for objects and bring them to the mouth
Begin to sit with support (not independently — independent sitting typically comes at 6–9 months)

9 months

Most children by 9 months:

Look when their name is called
React to strangers differently than familiar people (stranger anxiety is normal and expected)
Play peek-a-boo
Sit without support
Move objects between hands
Bang two objects together
Pick up small objects with a pincer grasp (thumb and finger)

9-month red flags: Not looking at the caregiver, not babbling, not sitting with support by 9 months — these warrant earlier evaluation rather than waiting for the 12-month visit.

12 months

Most children by 12 months:

Wave bye-bye
Call a caregiver “mama” or “dada” or an equivalent (one specific word with meaning)
Understand “no”
Point at things they want
Pull to standing
Walk while holding onto furniture (cruising) — independent walking typically comes between 9 and 18 months
Use the pincer grasp to pick up small objects precisely

12-month red flags: Not saying any words, not pointing, not looking where the caregiver points, not waving.

Gross motor: walking and the wide normal range

Walking independently — without holding on to anything — is one of the milestones parents watch most anxiously. The range is wide and normal: some children walk at 9 months, some not until 18 months. The CDC’s 2022 checklist sets 12 months as the age by which most children are pulling to stand. Independent walking by 15 months is expected for most children; absence of walking by 18 months warrants evaluation.

A child who is otherwise developing typically but is late to walk is much less concerning than a child who is not pulling to stand, has poor muscle tone, or has asymmetric motor development (using one side much more than the other). Asymmetric use of limbs at any age warrants prompt pediatrician attention.

Premature babies have an “adjusted age” — developmental milestones should be tracked against the due date, not the birth date, until approximately age 2. A baby born 8 weeks early would be expected to reach 6-month milestones at roughly 8 months after birth.

Language development: what is expected and what is not

Language development in the first year is primarily about receptive and pre-verbal skills — not words, but the building blocks of words.

0–3 months: Responds to sounds; startles to loud noises; calms to familiar voices.
3–6 months: Turns toward voices; babbles with back-and-forth vocalization.
6–9 months: Babbles with a variety of consonant sounds (ba, da, ma); responds to their name.
9–12 months: Says “mama” and “dada” with meaning; understands “no”; waves; points.

By 12 months, most children have 1–3 words with consistent meaning. A child who is 12 months old with no words, no gestures, and limited response to name should be evaluated promptly — early speech-language intervention for language delays has strong evidence for improved outcomes, and there is no advantage to waiting.

The “Learn the Signs, Act Early” program

The CDC’s Learn the Signs, Act Early campaign is a free resource that includes printable milestone checklists, a mobile app for tracking milestones, and plain-language guidance on what to do if you have concerns. The program exists because research consistently shows that earlier identification and intervention for developmental delays — particularly for autism spectrum disorder, speech delays, and motor delays — leads to better outcomes.

Early intervention services for children under 3 are provided through the federal Individuals with Disabilities Education Act (IDEA) Part C program. At well visits where milestones are discussed, your pediatrician will also review the vaccine schedule and screen for developmental concerns on the same timeline — the two-month, four-month, six-month, nine-month, and twelve-month visits each serve both purposes. These services are free or low-cost for eligible children and do not require a diagnosis — a developmental concern is enough to trigger an evaluation. Your pediatrician can refer; parents can also contact their state’s early intervention program directly. The NICHD’s developmental information resource provides an overview of the early intervention system.

Frequently Asked Questions

My baby isn’t walking at 12 months. Should I worry? Independent walking is typically expected between 9 and 18 months. A baby who is pulling to stand and cruising at 12 months is on track. A baby who is not pulling to stand by 12 months, or not walking independently by 18 months, warrants evaluation. Mention it at the 12-month well visit so the pediatrician can assess overall motor development.

Is it true premature babies reach milestones later? Yes — premature babies should be tracked on their adjusted age (based on due date, not birth date) until approximately 24 months. A baby born 2 months early who is chronologically 6 months old should be assessed at a 4-month developmental level. Most pediatricians track adjusted age automatically for premature infants.

My baby said a word at 9 months and then stopped saying it. Is that normal? Regression — losing a previously acquired skill — is always worth mentioning to the pediatrician, even if it is temporary. A single word that disappears for a few weeks during illness or a major change is usually not a sign of a problem, but sustained loss of language skills is a red flag that warrants evaluation.

At what age should I be concerned if my baby is not pointing? Pointing is typically expected by 12 months. Absence of pointing — or pointing to communicate, rather than just reaching — by 12 months is one of the red flags for autism spectrum disorder and warrants discussion at the 12-month well visit. The earlier a developmental difference is identified, the more effective early intervention services are.

How do I request an early intervention evaluation? In the United States, early intervention services for children under 3 are provided through each state’s Part C program under IDEA. You can request an evaluation by contacting your state’s early intervention program directly — you do not need a doctor’s referral, though most pediatricians will make the referral at a well visit if you raise concerns. Services that are recommended are free or low-cost regardless of insurance status.

Are developmental milestone apps accurate? Milestone tracking apps that use the CDC’s official checklist are a useful organizational tool — they help parents remember which skills to watch for and when. They cannot replace clinical evaluation. If an app flags a concern, bring it to your pediatrician; do not diagnose based on app output alone.