| John Hans Tester | ... | Udo (18 episodes) |
| Paola Turbay | ... | Dr. Marissa Caseras (15 episodes) |
| Kyle Howard | ... | Dr. Paul Van Dyke (15 episodes) |
| Christine Ebersole | ... | Ms. Newberg (14 episodes) |
| Anna George | ... | Rubina Katdare (12 episodes) |
| Michael B. Silver | ... | Ken Keller (12 episodes) |
| Bob Gunton | ... | General William Collins (12 episodes) |
| Stephen Spinella | ... | Russell Berger (11 episodes) |
| Anastasia Griffith | ... | Dr. Emily Peck (9 episodes) |
| Lisa Banes | ... | Ellen Collins (9 episodes) |
| Nick Diamantis | ... | Waiter
(8 episodes) |
| Ajay Mehta | ... | Devesh Katdare (8 episodes) |
| Greg Baglia | ... | Party Guest
(voice) (8 episodes) |
| Laura Benanti | ... | Shelby Shackelford (8 episodes) |
| Willa Fitzgerald | ... | Emma (8 episodes) |
| Tom Cavanagh | ... | Jack O'Malley
(7 episodes) |
| Mark Ivanir | ... | Dmitry Vasilyev (7 episodes) |
| Khotan | ... | Rafa
(7 episodes) |
| Meredith Hagner | ... | Libby (7 episodes) |
| Kat Foster | ... | Harper Cummings (6 episodes) |
| Frances Conroy | ... | Blythe Ballard (6 episodes) |
| Emilio Vitolo | ... | Bartender
(6 episodes) |
| Alexandra Socha | ... | Molly O'Shea (6 episodes) |
| Michael Mulheren | ... | Jim Harper (5 episodes) |
| James P. Anderson | ... | Attending Physician
(5 episodes) |
| Mark Steiger | ... | Surfer
(5 episodes) |
| Brad Beyer | ... | Don O'Shea (5 episodes) |
| Ezra Miller | ... | Tucker Bryant (5 episodes) |
| Michael Elian | ... | Israeli Bodyguard (5 episodes) |
| Martha Higareda | ... | Viviana (5 episodes) |
| Gillian Alexy | ... | Charlotte (5 episodes) |
| Anthony Pierini | ... | Wes (5 episodes) |
| Paul Weaver | ... | Garden Party Attendee (4 episodes) |
| Bruno Campos | ... | Charlie Casey (4 episodes) |
| Patrick Heusinger | ... | Adam Pierce (4 episodes) |
| David Fonteno | ... | Dr. Redliner (4 episodes) |
| JoAnna Garcia Swisher | ... | Dr. Nina Greene (4 episodes) |
| Timothée Chalamet | ... | Luke (4 episodes) |
| Julie Lauren | ... | Dr. Kathryn Neil (4 episodes) |
| Callum Blue | ... | Milos Kuester Ratenicz (4 episodes) |
