Half a Year Old: A 6-Month Milestones Checklist, Plus Signs to Mention at the Vaccine Visit
At 6 months, most babies roll from tummy to back, push up on straight arms, sit leaning on their hands, laugh, take turns making sounds and bring things to their mouth. Here are the signs to mention at the 6-month visit.
Half a year already! Your baby’s personality is showing more every day. They laugh out loud, stare at your face and babble back as if they understand. But then you meet a friend’s baby the same age who’s already sitting up alone, and you start to wonder if yours is behind.
Take a breath. Every baby has their own rhythm. We’ve gathered what most 6-month-olds can do, from the CDC and AAP, along with the signs worth noting down to tell the doctor at the 6-month vaccine visit. This checklist is for observing, not a test.
1. How to read the CDC 6-month checklist without stressing
Quick Answer: Items on the CDC checklist are things most children (75% or more) can do by that age. So if your baby can’t do 1 or 2 yet, that doesn’t automatically mean something is wrong.
The CDC uses the 75% threshold so that a missing item is a real reason to talk to the doctor, not something “half of babies can do.” So if you see several items your baby can’t do yet, or your baby could do something and now can’t, tell the doctor.
If your baby was born premature, go by corrected age: actual age minus the weeks born early. The AAP recommends using it for the first 2 years.
2. Social and emotional: your baby knows people now
Quick Answer: Most 6-month-olds know familiar people, like looking at themselves in a mirror, and laugh.
- Knows familiar people. Big smiles for mom, dad or grandma, but may go still or stare at strangers
- Likes the mirror. Put a shatterproof baby mirror down during tummy time and watch them light up
- Laughs. Loud laughs at peekaboo or tickles
3. Language: not talking yet, but already a great “chatter”
Quick Answer: Your baby takes turns making sounds with you, blows raspberries and squeals. No words are needed yet.
- Taking turns. You talk, baby answers with sounds, you pause and wait, baby makes sounds again. That’s your baby’s first conversation practice
- Raspberries. Tongue out, blowing until the drool flies. Messy, but great development
- Squealing. Little shrieks when excited
Try this: narrate what you’re doing all day. “Mommy is folding laundry. It’s a blue shirt.” Thai, Northern Thai or English, speak whichever language comes naturally.
4. Thinking: exploring the world with their mouth
Quick Answer: 6-month-olds put things in their mouth to explore, reach for toys they want and close their lips when they don’t want more food.
- Everything goes in the mouth. Totally normal, but it means it’s time to clear small things off the floor. See 10 spots to baby-proof when your baby starts crawling
- Reaching for what they want. The AAP says between 6 and 8 months babies start passing things from one hand to the other
- Closing lips when full. This matters when starting solids. Respect your baby’s fullness cues and don’t chase them to finish the bowl. Read more at Baby’s first meal
5. Movement: rolling, pushing up and starting to sit
Quick Answer: Most 6-month-olds roll from tummy to back, push up on straight arms on their tummy, and sit leaning on their hands.
| Skill | At 6 months (CDC) | What usually follows (AAP) |
|---|---|---|
| Rolling | Tummy to back | Both directions within 4 to 7 months |
| Tummy time | Pushes up on straight arms, lifts chest | Getting ready to crawl |
| Sitting | Sits leaning on hands | Sits without hand support around 6 to 8 months |
| Hands | Reaches and grabs | Passes between hands at 6 to 8 months, finger-and-thumb pincer grasp around 9 months |
Help your baby practice with daily tummy play on a mat or the floor while awake, instead of long stretches in a bouncer or baby walker. In a small condo, a single foam mat in the middle of the room is enough.
6. Signs to mention to the doctor at the 6-month visit
Quick Answer: If your baby can’t do several things on the checklist, has lost a skill, or you feel something isn’t right, tell the doctor. Don’t wait for the 9-month screening.
The 6-month visit is a vaccine visit. See the vaccine details at First-year vaccines in the Pink Book. The Ministry of Public Health’s DSPM developmental screening happens at 9, 18, 30, 42 and 60 months, but you can bring up concerns at any visit.
Tell the doctor if…
- Your baby doesn’t look at faces or smile back at familiar people
- Doesn’t make sounds back, or doesn’t startle or turn toward loud sounds
- Doesn’t reach for things, or always uses only one hand
- Seems unusually floppy or stiff, or still has weak head control
- Eyes are crossed all the time, or don’t follow objects
- Could do something before and now can’t. Don’t wait for the appointment for this one. Call for advice.
Go to the hospital now if…
- Seizures, jerking, or staring spells where your baby doesn’t respond
- Drowsy, hard to wake, refusing milk
- A knock to the head followed by repeated vomiting or increasing drowsiness
The big picture of the whole first year is in Your baby’s first year guide, and you can look back at early development in First-month milestones.
The last 6 months have surely been exhausting. Look back for a moment: from a tiny red newborn who could only cry, to a baby who laughs in your face. That’s your work too.
Checklist (tick and print)
Tick away, this device will remember.
Can your 6-month-old do these? (CDC checklist)
Tick what you see, then bring it with the Pink Book to the 6-month visit
Questions to bring to the doctor
Questions parents ask
01What can a 6-month-old baby do?
According to the CDC, most 6-month-olds know familiar people, like looking at themselves in a mirror, laugh, take turns making sounds, blow raspberries, squeal, reach for toys and put things in their mouth, roll from tummy to back, push up on straight arms and sit leaning on their hands.
02My 6-month-old can't sit on their own yet. Is that abnormal?
Not yet. The CDC says that at 6 months most babies sit leaning on their hands for support, and the AAP says sitting without leaning on the hands usually comes at around 6 to 8 months.
03My 6-month-old isn't rolling over yet. Should I worry?
The CDC says most 6-month-olds can roll from tummy to back. If your baby isn't rolling at all, or can't do several things on the checklist, mention it to the doctor at the next visit.
04Should a 6-month-old be talking yet?
No words are needed yet. At this age the CDC looks for taking turns making sounds with you, blowing raspberries and squealing. First meaningful words usually come around age 1.
05When does the hospital check my baby's development in Thailand?
The Ministry of Public Health screens development using the DSPM manual at 9, 18, 30, 42 and 60 months. But you can always raise concerns at any check-up or vaccine visit.
06My baby was born premature. Which age do I use for milestones?
Use the corrected age, which is the actual age minus the number of weeks your baby was born early, for the first 2 years. For example, a baby born 8 weeks early who is 6 months old should be compared with a checklist of around 4 months.
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