Crawling is no longer considered an official developmental milestone by the CDC, which removed it from their milestone checklists in 2022. That decision surprised many parents, but it reflects a growing recognition that crawling is highly variable: not all typically developing children crawl, the age of onset varies widely, and there isn’t even a consistent definition of what “crawling” means across research. That said, crawling still matters for development in ways worth understanding.
Why the CDC Removed Crawling
The CDC’s updated “Learn the Signs. Act Early.” checklists dropped crawling for several specific reasons. There was a lack of normative data on when crawling should happen, inconsistent definitions of crawling across studies, wide variability in when babies start, and no evidence that every typically developing child crawls at all. Some healthy babies skip crawling entirely and move straight to pulling up or walking.
The World Health Organization does track hands-and-knees crawling as one of six gross motor milestones, but with a massive range. The earliest 1% of babies begin crawling around 5.2 months, while the latest 1% don’t start until 13.5 months. That 8.3-month window is unusually wide compared to milestones like sitting or walking, which is part of why crawling is so hard to use as a reliable developmental marker.
What Crawling Does for the Body
Even though it’s not a required checkpoint, crawling provides real physical benefits. Weight-bearing on the hands helps develop the arches in the palm, which are critical for later fine motor skills like gripping a pencil, buttoning a shirt, or lifting objects. These arches direct the skilled movement of fingers and control grasp strength. Two of the three arches in the hand are flexible and maintained by small muscles that get strengthened through activities like crawling.
Crawling also builds shoulder stability, core strength, and wrist endurance. These are foundational for tasks children will rely on for years. For kids who skip crawling, activities like wheelbarrow walks, bear walks, and crab walks can provide similar weight-bearing benefits.
How Crawling Shapes Spatial Awareness
The onset of crawling is consistently linked with a burst of cognitive development. Once babies can move through space on their own, they gain self-initiated access to their environment, and that changes how their brain processes the world. Research published in Child Development found that crawling experience is associated with improvements in spatial search (finding hidden objects), position constancy (understanding that things stay in place even when you move), and optic flow perception, which is the ability to interpret visual patterns created by your own movement through a room.
Crawling also changes how babies see. Different body positions create different viewing angles, which alter the relationship between what a baby sees, what they feel in their joints, and what their balance system detects. These combined inputs help the brain build an internal map of the environment. Walking later adds another layer by giving babies visual access to more distant parts of a room, which may help with place learning, the ability to code locations relative to landmarks.
Six Crawling Styles That All Count
There’s no single “right” way to crawl. HealthyChildren.org, the parent-facing site of the American Academy of Pediatrics, identifies six distinct styles:
- Classic cross crawl: hands and knees, moving opposite arm and leg together
- Bear crawl: hands and feet with straight elbows and knees
- Commando crawl: pulling forward on the belly, military style
- Bottom scoot: sitting upright and scooting forward using the arms
- Crab crawl: moving backward or sideways, pushing off with the hands
- Rolling crawl: rolling across the floor to reach a destination
All of these get a baby moving independently through space, which is what drives the cognitive and motor benefits. A baby who bottom-scoots everywhere is still exploring, problem-solving, and building strength.
Tummy Time and Crawling Readiness
The single biggest thing parents can do to encourage crawling is provide plenty of tummy time. Cleveland Clinic recommends starting with two or three sessions a day lasting three to five minutes each during the newborn stage, then gradually building to 60 to 90 minutes total per day until your baby starts crawling. Most babies begin some form of crawling between 6 and 9 months.
Tummy time builds the neck, shoulder, and core strength that makes crawling possible. Babies who spend most of their time in containers (swings, bouncers, car seats) get fewer chances to develop those muscles. Floor time with interesting toys placed just out of reach gives babies a reason to push, pivot, and eventually move forward.
Motor Red Flags to Watch For
Since crawling itself isn’t a reliable benchmark, it helps to know what motor signs actually warrant concern. NHS developmental guidelines flag these by age:
- 6 to 8 months: strong hand preference (using only one hand), fisting, floppy tone, poor head control, or not reaching for things
- 12 months: unable to sit independently or bear weight when held standing
- 18 months: not walking
At any age, regression (losing skills a baby previously had), a rapid change in head circumference, or noticeably increased or decreased muscle tone are reasons for evaluation. The absence of crawling alone, without any of these other signs, is generally not a concern. What matters more is that a baby is finding some way to move through space, interact with objects, and progress toward pulling to stand and walking.