Masih was born in New York to a Punjabi father and a British mother, both of whom were medical missionaries.
[2] She attended Wellesley College, where she received a Bachelor of Arts, cum laude in international relations and French in 1994 and a Juris Doctor from the Creighton University School of Law in 1997.
[3][4] Throughout her 25-year legal career, Masih was with the firm McKanna Bishop Joffe in Portland and prior to her appointment to the bench, she was partner in the law firm of Bennett Hartman.
Her legal expertise centered around the Oregon Public Employees Retirement System and pension case law.
[5] On August 16, 2023, Governor Tina Kotek announced her appointment of Masih to the Oregon Supreme Court[5] to fill the vacancy left by the appointment of Adrienne Nelson to the United States District Court for the District of Oregon.