The American, a semi-finalist at the US Open back in 2005, will play Jesse Levine on Sunday with the winner earning a wildcard to next month's tournament in Melbourne.
Local hero Ginepri, who is currently ranked outside the world's top 300 following a lengthy spell on the sidelines due to injury, beat Rhyne Williams 7-5 6-2 in the semi-finals of the USTA's wildcard play-offs in Atlanta, Georgia, on Satruday.
Levine saw off Denis Kudla by the same scoreline.
In the women's event, Gail Brodsky continued her impressive run.
Having already beaten Melanie Oudin, she defeated top seed Coco Vandeweghe 6-3 3-6 9-7 on Saturday.
Brodsky will face 16-year-old Madison Keys in Sunday's final. Keys beat Alison Riske 3-6 6-4 6-1.