This study examines the consequences of variations in levels of openness in adoption, especially focusing on the dynamics of the adoptive family system from the perspective of the adoptive parents. Participants included the father, mother, and at least one adopted child in 190 adoptive families, and 169 birthmothers, drawn from adoption agencies across the United States. Families included 62 confidential, 17 time‐limited mediated, 52 ongoing mediated, and 59 fully disclosed adoptions. When compared to parents in confidential adoptions, those in open adoptions generally demonstrated higher levels of acknowledgment of the adoption, empathy toward the birthparents and their child, a stronger sense of permanence in the relationship with their child as projected into the future, and less fear that the birthmother might try to reclaim her child. Despite these mean differences, variations within all levels of openness were present, and results are discussed in terms of the ongoing process involved in building a family through adoption.