Q: Can a single person with a physical disability adopt a child?
A: Most states allow an adoption if the applicant passes a homestudy and if the needs of a child can be met. This vague statement is often left to licensed agencies to interpret, and interpretations may vary greatly. One agency may feel that a disabled person can be a parent if she hires someone to physically care for the child. Another may require that the parent be able-bodied enough to care for the child independently.
Beyond that, in domestic adoption, the parent is usually chosen by the birth parent(s). Based on my experience, birth parents rarely choose a disabled single parent if they have married couples to choose from. In international adoptions, the country acts as the birth parent. Many countries do not allow adoption by disabled people.
The bottom line is that adoption may not be an option for many disabled single people, unless they have an unusually supportive living situation.