What You Should Know About the Updated Developmental Milestones

by Toni Whitaker, MD TNAAP START Medical Director

Approach to Updating the Developmental Milestones 

In partnership with CDC, the American Academy of Pediatrics (AAP) identified and convened eight early childhood developmental experts. This work group established criteria for revising “Learn the Signs. Act Early.” (LTSAE) milestones and conducted a comprehensive literature review, cross-referenced with current developmental resources, to inform the revisions.

For information about the milestones checklists please visit “Learn the Signs. Act Early.” | CDC. To learn more about the process for making these revisions, refer to the peer-reviewed article, Evidence-Informed Milestones for Developmental Surveillance Tools | Pediatrics | American Academy of Pediatrics (aap.org)

[Zubler JM, Wiggins LD, Macias MM, et al. Evidence-Informed Milestones for Developmental Surveillance Tools. Pediatrics. 2022;149(3):e2021052138]

The milestones were revised for three reasons:

  1. To be able to offer a free milestone checklist for every age at which there is an American Academy of Pediatrics (AAP) recommended well-child health supervision visit between 2 months and 5 years to best facilitate conversations between parents and care providers at each of those visits, which meant adding the 15- and 30-month checklists;
  2. To assign milestones to ages when most children (75% or more) would be expected to exhibit them, to promote discussion and potentially action when a milestone is missed (rather than taking a “wait and see” approach).; and
  3. To address parents’ and early childhood professionals’ feedback that having very similar milestones across checklist ages was confusing, especially in terms of knowing when to take action on possible developmental concerns.

Of note, checklist revisions also include

  • Expanded tips and activities for supporting children’s development and
  • Added open-ended questions to help facilitate conversations between parents, healthcare providers, and others.

Here is what’s new: 

  • Updated nearly all of the developmental milestones included in existing materials to improve clarity, reduce confusion, reflect the current evidence for milestones, and reduce the likelihood of a “wait and see” approach to missed milestones
  • Developed 15- and 30-month milestone checklists to match health supervision visits. All typical health supervision visit ages now have a corresponding milestone checklist
  • Milestones are at the health supervision visit age where most (75% or more) children would be expected to achieve them
  • Revised and expanded the tips and activities to support children’s development for all ages
  • Added open-ended questions to help facilitate conversations with healthcare providers and others
  • “Warning signs” of development are now embedded within the milestones to reduce confusion about when to take action on missing milestones (any milestone missed is one on which action should be taken, typically beginning with a discussion, and often prompting developmental screening whether at a health supervision visit where screening would occur or not)
  • Redesigned the Milestone Moments booklet, adding a new screening “passport”, and refreshed the design of the milestone checklists, promotional milestones brochure, and gameboard poster

However, you will find that what you liked most about the materials has remained the same:  

  • They’re FREE 
  • Available in English, Spanish and some other languages
  • Colorful, engaging, and include images that reflect diversity
  • Written in family-friendly plain language at a 5th to 7th grade reading level 
  • Facilitate ongoing developmental surveillance and complement developmental screening 

Approach to Updating the Parent Tips 

The revised parent tips were developed through a comprehensive review process and cross-walked with common developmental promotion resources. The tips were revised based on previous experience with developing family-friendly, plain-language materials.

Where Can You Find the New Materials? 

Online: To access the new milestones by age and view or download a milestone checklist visit http://www.cdc.gov/Milestones

Print Materials: Order free copies of the Milestone Moments booklet in English or Spanish (in limited quantities) from www.cdc.gov/ActEArly/Orders. To request access to the customizable print files, email ActEarly@cdc.gov

Mobile App: As of Feb. 8, 2022, CDC has updated all milestone materials with the revised milestones, however, there may be a brief delay in the release of the updated Milestone Tracker app.

There has been significant interest in the new milestones since their release, along with some questions. The following answers to frequently asked questions may also be helpful:

  • The changes to the milestones were prompted by feedback over at least 15 years of use and began several years prior to publication. The review of evidence and revisions were completed in 2019 and parent testing for understanding and relatability was done in the summer of 2020.
  • On many developmental milestone checklists and for many of the milestones on the prior CDC materials, milestones were included on a list if at least half of children would be expected to reach it by that age. This meant that for some milestones, only half of children (50% or more) would be expected to meet them by the specified age. As a result, it wasn’t clear whether any action should be taken if a child was not meeting the milestone. By improving the milestones, and using available evidence to inform the lists, the aim was to make it clearer to parents and other care providers that missing a milestone was something to take action on. The updated milestones were chosen to reflect what most children (75% or more) would be expected to be able to do by specified ages to better identify potential concerns. 
  • In the process for review and revision, data were not available to support inclusion of all previous or all possible milestones. The new criteria sought data to support specific milestones for this revision. Data also supported that some milestones be kept where they were, and some milestones be moved to a different age, and sometimes to a new age checklist (to match health supervision visit time frames).
  • More than two thirds of the retained CDC Learn the Signs. Act Early. milestones were kept at the ages at which they were placed in the previous milestone checklists, although the wording used to describe the milestone may have changed, primarily to make it easier to understand. Milestones regarding verbal and nonverbal communication were added across checklists along with parent tips to support language development. Efforts were made to show the progression of communication and other skills across checklists, and the addition of 15- and 30-month checklists provides more opportunities to discuss child development. Open-ended questions were added to encourage discussion of concerns that milestones may not capture, such as concerns about a child’s clarity of speech.
  • The Learn the Signs. Act Early. Milestone checklists are health communication to engage families and support conversations about children’s development during well-child visits. They are NOT developmental guidelines or standards, nor are they meant to be used as a screening tool. These checklists may support, BUT DO NOT REPLACE, universal developmental screening recommended at well child/health supervision visits and any time there is a concern, as recommended by the American Academy of Pediatrics (AAP). The checklists and other Learn the Signs. Act Early. materials help inform parents of when screening is due, and support families in discussing concerns and asking about screening and other assessments if they have concerns. CDC’s Learn the Signs. Act Early. milestone checklists also provide parents with information on how to access early intervention programs in their state.
  • Developmental screening is recommended for all children by the AAP at the 9-, 18-, and 30-month well-child visits or any time there is a developmental concern, along with autism screening at the 18- and 24-month well visits using validated developmental screening tools. Screening tools (not the CDC’s Learn the Signs. Act Early. milestone checklists) can assess a child’s risk for developmental delays. Appropriate further evaluation is recommended if screening shows risks or if parents or providers still have concerns. Providers can refer with or without concerning screening results.
  • The Learn the Signs. Act Early. checklists
    • Inform parents that routine developmental screening is recommended at specific ages and any time there are concerns
    • Support families with tips and activities for how to encourage their child’s development
    • Inform families about how to access early intervention programs in their state
    • Support and complement, but do NOT replace, developmental screening as recommended by the American Academy of Pediatrics
    • Encourage parents to share any concerns they may have about their child’s development regardless of whether they are meeting the milestones
  • CDC and AAP wanted to make sure that the process for updating the Learn the Signs. Act Early. milestones was transparent, and therefore waited to implement changes until a peer-reviewed article describing the process was published in Pediatrics. This publication also
    • Raises awareness of the gaps in the literature around developmental milestones and other developmental issues;
    • Helps those using the Learn the Signs. Act Early. milestone checklists to know the purpose, as well as strengths and limitations, of developmental monitoring in general and of the Learn the Signs. Act Early. milestones specifically; and
    • Invites dialogue and future research not only on developmental milestones, but also developmental monitoring/surveillance, early identification, and intervention for developmental delays and disabilities.
  • The subject matter experts engaged by the American Academy of Pediatrics to review the Learn the Signs. Act Early. milestone evidence were:
    • Developmental-behavioral pediatricians
    • Neurodevelopmental pediatrician
    • General pediatrician
    • Speech language pathologist
    • Child and developmental psychologists
    • Professor of special education and early intervention
    • Developer of developmental screening tools
    • Editor of Bright Futures: Guidelines for Health Supervision of Infants, Children, and Adolescents, 4th Edition
    • Authors of AAP’s 2020 clinical report Promoting Optimal Development: Identifying Infants and Young Children with Developmental Disorders Through Developmental Surveillance and Screening

Thank you for your continued support in promoting this important information and resources to families, healthcare professionals, and early childhood providers. If you have questions about these updates, please email ActEarly@cdc.gov