From birth to age 3, kids are constantly changing. Their brains grow a staggering amount, which prepares them to connect socially, play, walk, and talk. It’s important to remember that regular doctor visits for your child are more than just shots and health screenings, but also include very important developmental screenings. These visits begin shortly after you bring your baby home, and involve measuring height and weight, performing a physical exam, giving appropriate vaccinations, and conducting developmental screenings as the baby grows.

Pediatricians know which milestones your baby should be hitting, and when, such as smiling for the first time. Each appointment allows your child’s doctor the chance to check in on your child’s progress. Often, the doctor will ask you what you’re seeing your child do at home and ask you to fill out questionnaires.

Milestones to meet

From birth up until 6 months, you’ll get to know your child’s pediatrician well with visits starting 2-3 days after discharge from the hospital, then again at 1, 2, and 4 months of age. From 6 months up until 2½ years old, the American Academy of Pediatrics recommends seven well-child visits. These are done at 6, 9, 12, 15, 18, 24, and 30 months old. Specific developmental screenings will happen at 9, 18, and 30 months, as well as screening for autism spectrum disorder (ASD) at 18 and 24 months.

You can find a full list of these milestones on the Centers for Disease Control and Prevention’s website. The CDC also has a handy Milestone Tracker App to record all the new things your baby is doing.

Here’s an overview of the developmental skills babies should be reaching, depending on their age. “If you feel your child isn’t meeting their development milestones, mention your concerns to your child’s doctor,” says David Burnham, M.D., a pediatrician with Lehigh Valley Reilly Children’s Hospital in Palmer Township, Pennsylvania. And don’t feel that you need to wait until the next office visit to speak up. “Ask early and act early,” Dr. Burnham says.

6 months old: Your baby will light up at the sight of familiar faces — they’ll certainly know their daddy and mommy and other people close to you. You’ll also be enjoying lots of baby belly laughs and squeals. Unfortunately, this is also the time when they’ll put everything in their mouths. (Think: bits of anything found on the floor, puzzle pieces, rocks and woodchips at the playground … you name it.) Baby should also be able to reach for toys while playing with you, roll from tummy to back, and sit up using their hands for help.

9 months old: Your once outgoing baby might now have a sense of stranger danger, making it suddenly difficult to drop them off at child care. Your baby is babbling up a storm and should be able to respond to their name. You can’t go anywhere without them, because they’ll want to cling right to your hip. (You’ll become skilled at making dinner with one hand.) Your baby should also be able to sit without help and move toys from one hand to the other.

12 months old: You and your baby can play simple games together. And you’ll love how they call you mama or dada. They know what “no” means (but might not listen). If you hide a toy under their blanket, they’ll go looking for it. Your little one is also moving around a lot — pulling themselves to stand and cruising along, holding on to the couch for support as they take their first steps.

15 months old: You get smothered in hugs, cuddles, and kisses these days. Your little one will try to talk more, using easy words like “ba” for ball. They can follow simple directions, point when they need something, and feed themselves with their fingers, and they’ve already taken a few steps.

18 months old: You may have been reading to your toddler for a while, but now you can tell they’re understanding what you’re reading. At this age, toddlers tend to be little chatterboxes, adding words to their vocabulary and playing with toys. They can walk without your help, try to drink out of a cup and even use a spoon. They may also be daring enough to climb onto furniture. Around 18-24 months old, doctors will check for delays in development specific to signs of autism spectrum disorder (ASD).

24 months old (2 years): When someone is hurt or sad, your child will notice (and may want to help). Your toddler can string two (or more) words together, can point to their tummy or head when you ask, eat independently with a spoon, run, and kick a ball. Their play is getting more complex. You’ll notice that they can hold something in one hand while using the other, press buttons on a toy, and play with more than one toy at the same time. It’s getting loud in the house these days!

30 months old: Your toddler can participate in parallel play (playing right next to but not necessarily with other children) and is kicking off their rich imagination with pretend play too. Their language has absolutely taken off. You’ve lost track of how many words they can say, but it should be about 50 words. More active than ever and confident in their bodies, your child is jumping now too.

Remember: You know your child best. At each checkup, educate your child’s doctor on their progress. Together, you both can make sure their growth is on track.