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2023 Yearbook

Attachment and Biobehavioral Catch-Up

Attachment and Biobehavioral Catch-Up (ABC) helps caregivers provide nurturing care and engage in positive parent-child interaction. ABC supports caregivers in reading children’s cues in order to provide a responsive, predictable environment to enhance children’s behavioral and regulatory capabilities. ABC offers two programs: one for infants and one for toddlers.

What is the model’s approach to providing home visiting services?

Home visits take place weekly. Services are provided for 10 weeks. For the infant program, ABC requires families to enroll when the child is between 6 and 24 months old. For the toddler program, ABC requires families to enroll when the child is between 24 and 48 months old.

ABC’s service population includes the following:

  • Families with low incomes
  • Families with a history of child abuse or neglect/involvement with child welfare system
  • Families who consider their child to be growing up in a challenging environment
  • Children experiencing a caregiving transition (e.g., foster care placement, adoption)

Who is implementing the model?

Home Visitors

ABC was implemented by 157 home visitors in 2020. Home visitor education recommendations and requirements are determined by local agencies. There are no requirements for home visitor caseload limits.


ABC was implemented by 45 supervisors in 2020. Supervisor education recommendations and requirements are determined by local agencies.

Where is the model implemented?

ABC operated in 60 local agencies across 16 states and the District of Columbia in 2020. ABC also operated outside the United States and its territories in Australia, Canada, Germany, Norway, Russia, Sweden, South Africa, and Taiwan in 2020.

US map with Attachment and Biobehavioral Catch-Up service area highlighted

Families Served Through Evidence-Based Home Visiting in 2020

home visits provided
including 4,788 virtual visits
families served
children served


ABC aims to support infants and toddlers who have experienced early adversity, such as neglect or a change in caregivers. Parent coaches help caregivers learn to follow their children’s lead with delight, behave in nurturing ways when children are distressed, and avoid behaving in frightening or intrusive ways.


Twenty-five years ago, Dr. Mary Dozier and her colleagues and students at the University of Delaware’s Infant Caregiver Project developed ABC to address the needs of infants in foster care. ABC was tested in three randomized controlled trials studying infants in foster care, infants living with birth parents in a foster care diversion program, and infants adopted internationally. These studies showed positive short- and long-term effects on children’s attachment, diurnal cortisol patterns, self-regulation, and language development; positive effects were also noted for parents’ behavior and neurobiology. Model developers identified parent coaches’ “in-the-moment” comments to participants as ABC’s mechanism of intervention and developed clear fidelity criteria for replication. The model is now disseminated across the United States and internationally. It is currently being evaluated in several independent effectiveness trials.