The patient arrived in a specially equipped jet at Dobbins Air Reserve Base in Marietta, Georgia, late Tuesday morning. She will be taken to an isolated unit at Emory University Hospital for treatment.
Although hospital officials haven't released the patient's identity, the aid group she was working with has identified her as 59-year-old Nancy Writebol.
SIM says in a statement that Writebol remains in serious but stable condition.
Dr. Kent Brantly, a physician with North Carolina-based Samaritan's Purse, arrived in Atlanta for treatment Saturday. Both contracted Ebola while treating patients in Liberia.
Ebola has killed at least 887 people in four West African countries in what's considered one of the largest outbreaks ever.