This AAC legislative policy statement was updated on 5/29/2018:
It is the formal policy of The American Adoption Congress to support state-by-state legislative efforts to restore unrestricted access to original birth certificates (OBC) for all adult adoptees. This is also known as “clean” adoption reform, which is in accordance with widely accepted best practices in adoption. As an umbrella organization, the AAC will also support efforts to gain access to all adoption agency and court records if planned within legislation or government actions.
Our State Adoption Legislation page shows all of the U.S. States and what the access is for each one. This is kept up as legislation changes within each state.
There are reform materials and also Landmark Court Rulings.