[9] Spergel graduated summa cum laude with a Bachelor of Arts (AB) from Princeton University in 1982,[10] after completing a senior thesis on red giants under the supervision of Gillian R.

[14] Citing the hesitance to hold onto 2 positions,[6] he retired from Princeton University in 2019 at the age of 59, and has remained as emeritus professor since.

[15] Spergel is a 2001 MacArthur Fellow,[12] and was a member of the NASA Advisory Council and chair of the Space Studies Board.

[9][17] Currently, he is a member of the Simons Observatory,[18] chairs the Science Definition Team of the Nancy Grace Roman Space Telescope (formerly known as the Wide-Field Infrared Survey Telescope),[19] and sits on the Board of Trustees of the Carnegie Institution for Science (since 2022).

[20] In 2022, Spergel was invited to lead NASA's UAP independent study team of sixteen members to provide guidance in better understanding "unidentified anomalous phenomena".