21-month milestones: what is emerging next
21-month milestones: there is no CDC checklist for 21 months, so keep using the 18-month one (15 items), as CDC advises between two ages. The 24-month checklist is three months off, and this page lists its 13 items with an activity for a 21-month-old beside each.
Updated
CDC 18-month milestone checklist
At 21 months use the 18-month checklist (CDC: use the earlier checklist between ages); next checklist at 24 months.
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Social and emotional
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At 21 months, try Nature Tote Treasure Walk (10–20 min, 16–28 months)
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At 21 months, try Brush and Hands Wash-Up (3–8 min, 20–36 months)
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At 21 months, try Where's the Dog? Book Hunt (5–12 min, 18–30 months)
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At 21 months, try Toe-Tug Sock Off (2–5 min, 12–20 months)
Language and communication
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At 21 months, try Unpack the Shopping Tote (5–12 min, 20–28 months)
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At 21 months, try Ready-Set-Go Chalk Dash (5–12 min, 19–31 months)
Cognitive (learning, thinking, problem-solving)
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At 21 months, try Taped-Down First Scribbles (5–10 min, 14–24 months)
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At 21 months, try Two of a Kind Kitchen Match (5–8 min, 14–24 months)
Movement and physical development
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At 21 months, try Towel Speed-Bump Walk (4–10 min, 14–22 months)
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At 21 months, try Copy My Crayon Line (5–10 min, 24–34 months)
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At 21 months, try Two-Hands Open Cup Sip (2–5 min, 12–20 months)
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At 21 months, try Snack Tub Lid Twist (3–10 min, 20–34 months)
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At 21 months, try Basin Spoon Scoop (5–15 min, 18–28 months)
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At 21 months, try In and Out Basket Climb (5–10 min, 12–20 months)
A checklist is monitoring, not a screening test. If your child loses a skill they had, or something worries you, talk to your pediatrician; in the U.S. you can also contact your state's Early Intervention program directly, no referral needed.
21 months at a glance
| CDC checklist for 21 months | None (CDC's checklists in this range: 12, 15, 18, 24, 30, 36 months) |
|---|---|
| Checklist that applies now | 18 months (15 items), reached three months ago |
| Next checklist | 24 months (13 items), in three months |
| Where this month sits | In-between month 3 of 5 from 18 to 24 months |
| Library activities that fit 21 months | 152 (age band overlapping 19-24 months) |
| Skills building at 21 months | 64 of the 67 everyday skills on this site |
| Born early | Corrected age applies: born 8 weeks early, 21 months is about 19 mo 1 wk corrected |
Which checklist applies at 21 months
Three months after the 18-month checklist and three before the 24-month one, a 21-month-old sits in the middle of a 5-month stretch with no CDC list of its own; CDC's rule is to keep using the earlier checklist, here the 18-month one.
The 24-month list has 13 items (2 social-emotional, 4 language, 3 cognitive and 4 movement). They are not expected at 21 months; they show what is emerging next. Thirteen of them have an activity below that fits this month.
24-month milestones to watch for at 21 months
Each 24-month item with an activity for a 21-month-old, and how the activity's age band relates to 21 months:
| By 24 months (CDC) | Area | Try at 21 months |
|---|---|---|
| Reacts when someone is hurt or upset, for example stopping or looking sad when another person cries. | social-emotional | Teddy's Doctor Check-Up (a stretch, band starts at 24 mo) |
| Looks at your face to work out how to react when something is new. | social-emotional | Teddy Is Sad: Comfort Game (a stretch, band starts at 22 mo) |
| Points to the right picture in a book when you ask something like "Where is the dog?" | language | Lap Book Point and Pause (an easy win, band ended at 20 mo) |
| Joins at least two words together, like "more juice". | language | Cardboard Garage Parking Talk (new in its 21-32 mo band) |
| Shows you two or more body parts when you ask, such as nose or tummy. | language | Nose-to-Nose Mirror Game (mid-band, 15-26 mo) |
| Uses gestures beyond waving and pointing, such as nodding for yes or blowing a kiss. | language | Clear Tub Ask for Help (late in its 14-22 mo band) |
| Holds an object steady in one hand while working with the other, like gripping a container and pulling off its lid. | cognitive | Snack Tub Lid Twist (new in its 20-34 mo band) |
| Tries to work the buttons, knobs or switches on a toy. | cognitive | Box Lid Ramp Races (mid-band, 17-27 mo) |
| Combines two toys in play, such as setting pretend food on a toy plate. | cognitive | Teddy's Snack Time (an easy win, band ended at 20 mo) |
| Gives a ball a kick. | movement | Kick into the Box Goal (mid-band, 18-30 mo) |
| Runs, not only walks. | movement | Ready-Set-Go Chalk Dash (mid-band, 19-31 mo) |
| Walks up a few stairs, rather than climbing on hands and knees, with or without help. | movement | Count-the-Stairs Walk Up (mid-band, 16-28 mo) |
| Feeds themselves with a spoon. | movement | Pre-Loaded Spoon Hand-Off (an easy win, band ended at 20 mo) |
Activities toward the 24-month milestones
13 activities picked for 21 months, by CDC area. In Box Lid Ramp Races, for example, watch for this sign of progress: lets go at the top instead of pushing it down by hand.
Social-emotional at 21 months
Language at 21 months
Cognitive at 21 months
Movement at 21 months
What changes in the activity plan at 21 months
The family plan offers an activity from 3 months before its age band until 2 months after it. At 21 months, 23 activities join (band starting at 24 months), three bands start right at 21 months and seven activities leave (band ended at 18 months):
- Joins the plan: Picture-Label Toy Homes, for 24-34 mo: simple drawings on sticky notes mark which box each kind of toy lives in, so your child can match toys to their homes at cleanup.
- Joins the plan: Teddy's Doctor Check-Up, for 24-34 mo: your child plays doctor for a stuffed animal, listening through a cardboard tube, checking ears and wrapping a sore paw, a pretend routine for talking about checkups.
- Joins the plan: Crayon Leaf Rubbings, for 24-36 mo: leaves from a walk go under a sheet of paper and your child rubs over them with the side of a jumbo crayon until the veins and edges appear.
- Band starts at 21 months: Feelings Faces in Board Books (21-33 mo), during shared reading you stop on a character's face, name the feeling and the reason, and pause for your child to point, make a sound or answer.
- Band starts at 21 months: Dough Pancake Café (21-32 mo), your child flattens play dough, cooks pretend pancakes on a baking sheet, flips them with a wooden spoon and serves a customer, a three-step pretend script.
- Band starts at 21 months: Cardboard Garage Parking Talk (21-32 mo), park toy cars in a cardboard-box garage while you turn your child's single words into two-word phrases like "car in" or "red car".
- Leaves the plan: Two-Choice Snack Pick, whose 12-18 mo band ended three months ago.
- Leaves the plan: Gentle Hands for Teddy, whose 12-18 mo band ended three months ago.
- Leaves the plan: Ice Tray Snack Picking, whose 12-18 mo band ended three months ago.
Skills commonly building at 21 months
64 everyday skills on this site have 21 months inside their age window. Six of them, with where 21 months falls and their usual timing:
- Using objects the right way, late in its window (12-24 months): Trying to use things the right way, such as a phone, cup or book, is a CDC 15-month milestone; playing with toys in a simple way, like pushing a toy car, is a CDC 18-month milestone.
- Body parts, mid-window (14-30 months): Pointing to at least two body parts when asked is a CDC 24-month milestone.
- Hand washing, early in its window (15-36 months): Holding hands out for you to wash them is a CDC 18-month milestone.
- Asking questions, early in its window (18-36 months): Asking "who", "what", "where" or "why" questions is a CDC 36-month milestone.
- Counting, early in its window (18-36 months): Counting is not on the CDC checklists at these ages.
- Jumping, early in its window (18-36 months): Jumping off the ground with both feet is a CDC 30-month milestone.
When to talk to your pediatrician at 21 months
Talk to your pediatrician if a 21-month-old loses a skill they used to have, if 18-month items such as “climbs onto and down from a couch or chair without help” or “holds out their hands so you can wash them” are still missing at 21 months, or if anything else worries you. From 21 months, the next AAP-recommended checks are an autism screening at 24 months (three months away) and a general developmental screening at 30 months (nine months away).
CDC milestones are things most children (75% or more) can do by that age; the checklists are for monitoring and are not a standardized screening tool. In the U.S. you can contact your state's Early Intervention program for children under 3 yourself; no doctor's referral is needed.
Born early? Corrected age at 21 months
CDC suggests using corrected age (age minus the weeks born early) for a child born more than 3 weeks early, and the AAP advises it for the first 2 years. At 21 months by the calendar, that changes which checklist fits:
| Born | Corrected age at 21 mo | Checklist to use | 24-month list from |
|---|---|---|---|
| 4 weeks early | 20 mo | 18-month | 24 mo (correction stops) |
| 8 weeks early | 19 mo 1 wk | 18-month | 24 mo (correction stops) |
| 12 weeks early | 18 mo 1 wk | 18-month | 24 mo (correction stops) |
| 16 weeks early | 17 mo 1 wk | 15-month | 24 mo (correction stops) |
Frequently asked questions
How much should a 21-month-old talk?
CDC gives no list for 21 months. The 18-month checklist says: attempts at least three words besides "mama" or "dada". By 24 months it adds: joins at least two words together, like "more juice" and uses gestures beyond waving and pointing, such as nodding for yes or blowing a kiss.
What should a 21-month-old be doing?
Most children (75% or more) do the 15 items of the 18-month checklist by 18 months, such as: climbs onto and down from a couch or chair without help and holds out their hands so you can wash them. Emerging next, for the 24-month list: gives a ball a kick and feeds themselves with a spoon.
Which activities help a 21-month-old toward the 24-month milestones?
This page picks 13 library activities that fit 21 months, one or two per 24-month item, for example Count-the-Stairs Walk Up, Ready-Set-Go Chalk Dash and Teddy's Doctor Check-Up. Short, playful repeats work better than drills.
What if my 21-month-old has not reached these milestones?
The 24-month items are not due at 21 months. If 18-month items are missing, if a skill is lost or if you are worried, talk to your pediatrician now. From 21 months, the next AAP-recommended checks are an autism screening at 24 months (three months away) and a general developmental screening at 30 months (nine months away). In the U.S. you can also call your state's Early Intervention program without a referral.
My 21-month-old was born early: which age do I use?
Use corrected age until 24 months if your child was born more than 3 weeks early (CDC; the AAP advises corrected age for the first 2 years). For example, a child born 8 weeks early is about 19 months, 1 week corrected at 21 months, so the 18-month checklist applies.
Related
Milestones month by month
Plan for 21 months
Born early
Skills building at 21 months
Monitoring, not medical advice. Talk to your pediatrician about any concern. Our sources and method.