A final order is hard to undo
Courts treat a finalized adoption as permanent because the child's stability depends on it. New York courts can be asked to vacate an adoption order in narrow circumstances, typically involving fraud or a fundamental defect in the proceeding, and the child's welfare weighs heavily even then. Being disappointed in how the adoption turned out, or discovering health problems after the fact, does not ordinarily undo it. Where an agency withheld information about the child, the question is often whether there is a claim against the agency rather than whether the adoption ends. While that question is being explored, the adoptive parent's duty of support generally continues.
Termination of parental rights is a different case
People sometimes say termination of adoption when they mean termination of parental rights, the separate proceeding that frees a child for adoption in the first place, usually brought by an agency in Family Court. If a child welfare agency is involved with your family, the distinction matters, because the parent's rights and the timelines in that case are specific. An adoptive parent can be the subject of such a proceeding just as a birth parent can. Gather the adoption decree, any petition you have been served with, and correspondence with the agency, and note the court and docket number on each document.
Adult adoptees and changing family ties
An adult who was adopted as a child may want to restore a legal relationship with birth relatives, change a name, or clarify inheritance. Undoing the original adoption is rarely the path. Depending on the state, a new adult adoption, a name change, or careful estate planning can sometimes accomplish what the person actually wants. In a first conversation we identify what you are trying to change, whether a court proceeding is needed at all, and which court would hear it. We also flag effects that people overlook, such as how a change would interact with existing wills, trusts, or benefits.