Where this guide comes from.
Milestones were summarized from CDC Learn the Signs. Act Early. guidance; routines and safety guidance draw on American Academy of Pediatrics and ASHA sources. Use the original resources for the full checklists and for advice tailored to your child.
This guide condenses and reorganizes public guidance so it is readable in one sitting — which means it necessarily leaves things out. The primary sources below are the authoritative version, they are free, and the printable CDC checklists in particular are worth putting on your fridge. When this guide and a primary source disagree, or when your clinician says something different, the clinician who has examined your child wins.
Start with these.
Seven references, in rough order of usefulness to a parent. All free, all maintained, none of them selling anything.
The single most useful thing on this page. Printable one-page checklists covering 2 months through 5 years, with a short list of what most children do and specific prompts for what to do if something is not happening. Print them all and keep them with the growth chart.
Open the checklistsThe same milestones as an interactive, age-by-age tool, with activity suggestions attached to each one. Better than the PDFs if you want to look something up quickly rather than print it.
Open the online toolWhat to do first when you have a worry: how to describe it, how to ask for screening, and what the process looks like after you do. Read this one before an appointment rather than after.
See the next stepsHow U.S. families can request a free developmental evaluation for a child under 3 without waiting for a doctor's referral, and what happens from age 3 onward through the public school system.
Learn about early interventionAmerican Academy of Pediatrics guidance on safe infant sleep and on supervised tummy time — the two halves of the same safety-and-development picture, and the source behind this guide's sleep section.
Read the guidanceReadiness signs, textures by age, allergen introduction, and the choking-prevention basics. The most detailed plain-language feeding reference on this list, and it is written for parents rather than clinicians.
Read the feeding guideAdvice from speech-language pathologists on raising a child with more than one language, including what to do when there is a genuine speech or language concern and the reasons not to drop the home language.
Read the language guidanceIf you only save two links.
One for what to expect, one for when to worry. Together they cover most of what a parent actually needs from a guide like this.
What to expect
Print the CDC milestone checklists for your child's current age and the next one up. Write the date on them. When you are at a well-child visit and cannot remember what to ask, read the checklist aloud — it is organized as questions.
When to worry
Save your state's early intervention intake number in your phone under something you will find in a hurry. It costs nothing to call, they will tell you honestly whether an evaluation is warranted, and you can self-refer.