The Only 15-Month Milestones That Matter

Most parents with a 15-month-old have their hands full with a busy baby transitioning into toddlerhood. Both physically and cognitively, babies at this age are interested in the world around them and have a desire to be active participants. However, the 15-month milestones kids typically reach around this age require parents to shift their style of attentiveness from constantly meeting needs to keeping their baby safe as they follow their curiosity.

Every kid hits developmental milestones at their own pace, and for a lot of 15-month-olds, that will depend on environmental factors. Babies who are carried all the time, for example, may take longer to develop the leg muscles and coordination required for standing and taking first steps. And temperament can play into how eager a child is to try new types of movement as some kids are content to scoot and crawl if it gets them where they want to go.

Fifteen-month milestones did not exist until recently. In February 2022, the Centers for Disease Control and Prevention and the American Academy of Pediatrics overhauled the pediatric milestone checklist. This process included adding developmental milestones for 15-month-olds.

So what is within the typical development scope at 15 months, and what’s cause for concern? The developmental milestones that matter at this age are guidelines that parents should consider in light of their child’s personality and surroundings. It’s less about whether they’re putting all of the pieces together for increasingly complex thought and movement and more about the developmental trajectory of your particular kid — and keeping an eye out for skills they’ve missed that may be red flags for developmental delays.

15-Month Developmental Milestone #1: Shows Preference

As babies develop, their preferences become less and less ambiguous. They begin to develop choices and the ability to communicate them. And although this can sometimes be a recipe for tantrums, it’s also the capacity that allows for some of the most heartwarming moments parents experience. Some 15-month olds will be able to show you specific objects they like and demonstrate excitement when excited. And one of the things kids this age are particularly fond of is their parents, which means they start showing affection through hugs, cuddles, and kisses.

Red Flags: A 15-month-old should show interest in other children and an affinity for familiar people. If they remain incurious or ambivalent, talk to your pediatrician about specific ways to facilitate relational connection with your child.

What You Shouldn’t Stress About: Kids can have a short fuse at this age. When they have an outburst, stay calm and empathetic while considering any needs you can meet to help them feel better. Fifteen-month-olds typically respond well to specific questions instead of broader ones, so asking if they would like a particular food instead of whether or not they are hungry is often a better tactic.

15-Month Developmental Milestone #2: Language Use Grows

Beyond “mama” and “dada,” 15-month-olds will start referring to familiar objects, such as the family pet or a favorite toy. They will also begin to understand that different things are used for specific purposes. For instance, a toddler might pick up your phone and hold it up to their ear as if talking to someone.

As their comprehension improves, kids at this age will be able to follow simple, one-step instructions given with both a gesture and a word, as when you hold out your hand and say, “Give me the phone, please.”

Red Flags: Although your child may not have a growing vocabulary by 15-months, it is a concern if they aren’t babbling by this age. A speech pathologist can perform a comprehensive assessment of your child’s expressive and receptive language by evaluating various verbal and nonverbal communication skills. They may also recommend a hearing exam, as overlooked hearing impairments can slow language development.

What You Shouldn’t Stress About: What kids understand and can communicate tend to develop on different schedules. They will likely understand far more than they can share. If your child is slower to move from babbling to specific words, it’s not an urgent concern as long as they appear to comprehend and respond to what you’re saying.

15-Month Developmental Milestone #3: Muscle Development

Babies who have adequately developed leg and torso muscles will start venturing around the house via foot and may start climbing stairs or onto furniture. It’s the season of the busy baby as increased mobility is accompanied by what can seem like insatiable curiosity.

It’s also a time of fine motor development as kids learn to use their hands and fingers more purposefully. Increased dexterity and developing spatial reasoning skills allow them to play sorting games, stack blocks, and attempt to feed themselves with small utensils.

Red Flags: Some kids aren’t eager to walk, but if your baby can’t stand even while being supported, it may be a sign of muscle delays. Also, be aware if your child doesn’t show interest in playing with toys or searching for items that you try to hide from them.

What You Shouldn’t Stress About: 15-month-olds are messy. They will spill things, run into furniture, regularly fall over, and empty shelves onto the floor. If your child’s movements seem clunky, it’s likely they’re still coordinating the complex movements needed to roam and explore. As long as the foundational skills are there, they will put it all together soon enough.

Non-Milestone Moments Between Baby’s 15th and 18th Months

Prepare for your toddler to expose holes in your baby-proofing efforts. Tools such as baby gates will help keep your child confined to specific areas of the home. In addition, cabinet locks are a must for any space that houses potentially dangerous items, and moving fragile objects out of reach will save some trouble down the road.