- Greg Grunberg - Sean Blumberg
- Greg Grunberg - Sean Blumberg (voice) (uncredited)
- Ian Gomez - Javier Clemente Quintata
- Ian Gomez - Javier
- Rob Benedict - Richard Coad
- Wesley Jonathan - Max
- Tyra Banks - Jane Scott
- Tracy Scoggins - Kelly
- Brian Howe - Eric Scott
- Monica - Sarah Robinson
- Sarah Jane Morris - Zoe Webb
- Chris Engen - Finn
- Sean O'Bryan - Paul
- Donald Faison - Tracy
- Eve Gordon - Barbara Porter
- Eve Gordon - Barbara Hunter
- Amy Smart - Ruby
- Darnell Williams - John Papaleno
- Erich Anderson - Dr. Edward Porter
- Staci B. Flood - Co-Star
- Norma Maldonado - Principal
- Jean St. James - Ben's Mother
- Barbara Allyne Bennet - Adminstration Worker (uncredited)
- Hunter Bodine - Ben's Buddy
- John Cho - Larry
- Brent Roam - Male Student
- Jan Schweiterman - Lewis
- William Monaghan - Mr. Rogalsky
- William Monaghan - Professor Rogalsky
- William Monaghan - Professor Regalsky
- Constance Zimmer - Girl
- Harold Gould - Dr. William Garibay
- David Proval - Mr. Kinney
- Marissa Ribisi - Astrid
- Boris Lee Krutonog - Yuri
- Ivana Miličević - Sensa
- Jillian Bach - Alice
- Marc Worden - Jerry
- Jed Rhein - Mitch
- Devon Gummersall - Zach
- John Billingsley - Delivery Guy
- Rick Gianasi - Waiter
- Clay Wilcox - T.A. Mark
- Sam Shamshak - Detective Graziano
- Sebastian Tillinger - Andrew
- Christien Anholt - Paul
- Andy Hubbell - KBLB Goalie (uncredited)
- Lucinda Lewis - Pink Power Ranger (uncredited)
- Tiger Mendez - Building Painter / Taxi Passenger (uncredited)
- Shan Omar Huey - Blair
- Shan Omar Huey - Blair / Tin Man
- Leslie Olivan - Tiffany (uncredited)
- Ron Canada - Dean Allison
- Lorna Raver - Professor Linda Cohen
- Helen Siff - Food Service Employee
- Eddie Kaye Thomas - P.J.
- Joe Nicchi - Greg (uncredited)
- Evan Jones - R.A. #1
- Judy Herrera - R.A. #3
- Cory Hardrict - R.A. #4
- China Shavers - R.A. #5
- Riley Weston - Story Zimmer
- Jacqueline Hahn - Kerry Lerner
- Brian Klugman - Guy
- Elizabeth Payne - Dr. Palucci
- Bob Stephenson - Officer Dennis
- John Cothran - Mr. Tyler
- Jennifer Garner - Hannah Bibb
- Eric Saiet - Waisler
- Steve Monroe - Steve
- Maulik Pancholy - T.A.
- Lela Lee - Pauline
- Liza del Mundo - Random
- Eddie Santiago - Math Major
- Brennan Feonix - Student (uncredited)
- Taraji P. Henson - Art Student
- Taraji P. Henson - R.A. #2
- Roz Witt - Salesperson
- Alec Ledd - Dorky Guy
- Ginger Williams - Girl
- Elya Baskin - Bela
- Donal Logue - Eddie
- Tammy Townsend - Tara Owens
- Jane Kaczmarek - Carol Anderson
- Ian Busch - Receptionist
- Susan Dalian - Tina
- Janeane Garofalo - Sally Reardon (voice) (uncredited)
- Janeane Garofalo - Sally Reardon (voice)
- Jarrod Crawford - Daryl
- Jarrod Crawford - Darryl
- Chris Sarandon - Dr. Peter McGrath
- Stephen Berra - Todd Mulcahy
- Maggie Lawson - Rebecca
- Simon Rex - Eli
- Dahlia Waingort - Charlotte
- Freddy Andreiuci - Paramedic
- Chariesse LaVelle - Nurse
- Karl T. Wright - Doctor #2
- Dash Mihok - Lynn McKennan
- Eddie McClintock - Ryan Crane
- Amy Hathaway - Nicole
- Nathan Anderson - Alex
- Drew Pillsbury - Swim Coach
- Anna Garduno - Waitress
- Spencer Beglarian - Samuel
- Ali Wentworth - Abby
- Matagi Booker - Art Student
- Kent Dalian - Wes
- Jamie Hanes - Employee
- Ali Hillis - Chloe
- Sharon Maughan - Professor Beisner
- Nancy Lenehan - Faye Rotundi
- Paul Vincent O'Connor - Walter Rotundi
- Marina Malota - Amanda Anderson
- Joey Zimmerman - Matthew Anderson
- Bradley Whitford - Tom Anderson (uncredited)
- Don Perry - Hypnotist
- Gregg Daniel - Financial Aid Officer
- Curtis Armstrong - Danny
- Chad Gabriel - Barry
- Steve Hofvendahl - Loan Officer
- Kerry Leigh Michaels - Nun
- Bob Clendenin - Mr. Norman
- Bob Clendenin - Dominic (uncredited)
- Bob Clendenin - Dominic
- Christopher Pelant - Scott (uncredited)
- Max Baker - Aaron
- Peter Dennis - Star Wars Fan
- Rick Zieff - Obi-Wan Kenobi
- Burt Bulos - Student
- Michelle Benes - Caitlin's Mom (uncredited)
- Devin McGinn - Student (uncredited)
- Cinzia Roccaforte - Drug Addict (uncredited)
- Michael Peña - Brian Burke
- Brittany Ishibashi - Advisee
- Marissa Jaret Winokur - Nancy
- Lamya Jezek - Eve
- David Reivers - Housing Worker
- Jeanette Brox - Gretchen
- David Haley - Tim
- Stephanie-Marie Baker - Bridgid
- L.B. Fisher - Carl
- Sally Kirkland - Professor Annie Sherman
- Trevor Lissauer - Andrew
- Larry Sullivan - Preston
- David Bowe - Lloyd
- David Bowe - Jerry
- David Bowe - Photographer
- Reagan Gomez-Preston - Student
- Nancy Jeris - Administration Worker
- Michael Weiner - Bruce
- Diva Zappa - Student #2
- Teri Polo - Maggie Sherwood
- Rockmond Dunbar - Man on Train
- Carl Gordon - Older Man on Train
- Tom McCleister - Loren
- Jullian Dulce Vida - Vendor
- Phyllis Applegate - Mimi
- Juan Fernández - Dennis
- Ty Hodges - J.D.
- Christopher Neiman - Judd
- Rebecca Street - Judith
- Henri Lubatti - David Sherman
- Marian Filali - Waitress
- Brooke Bloom - Brent
- Emily Wachtel - Suzanne
- Sung Kang - Student
- David Starzyk - Mr. Charlie Sherwood
- Brad Everett Young - Laughing Art Student
- Brad Everett Young - Art Student
- Jill Parker-Jones - Vet
- Django Craig - Buddy
- Paul Sutera - Wes
- Jeffrey J. Ayers - Man Holding a Dog
- Amy Wilson - Sabrina Briscoe
- Amy Wilson - Seminar Student
- Ed Redlich - El Duque
- Adam Rodriguez - Erik Kidd
- Tinsley Grimes - Gwen
- Greg Rikaart - Art Student
- Scott Berman - Marcus
- Kris Iyer - Cashier
- Miguel Nájera - Professor Elliott
- Daryl Keith Roach - Security Guard
- Dennis Lipscomb - Doctor
- Cynthia Ettinger - Janice King
- Lynn Wanlass - Woman
- Michael Morrissey - Corpse
- Scott Alan Smith - Anesthesiologist
- Amy Aquino - Dr. Toni Pavone
- Christian Aubert - Professor Middleton
- Michelle Beauchamp - French Class Student
- Chris William Martin - Greg Stenson
- Bruce Nozick - Larry
- Ron Perkins - Dr. Martin
- Paige Hurd - Natasha
- Elizabeth Bogush - Pam
- Ciro Barbaro - Reviewer
- Keiko Agena - Leila Foster
- Anne DeSalvo - Helen Blumberg
- Anne DeSalvo - Lawyer
- Ben Donovan - Rodney
- Elizabeth Liang - Sue Morgan
- Fred Sanders - Dr. John Sullivan
- Alexis Arquette - Jim
- Henry Dittman - Doug
- Hal Ozsan - Long-Haired Guy (voice)
- Hal Ozsan - Student / Stoner Guy (voice)
- Buck Kartalian - Guard
- Alex Carter - Stephen's Father
- Jesse James - Stephen
- Maya Goodwin - Former President
- Eric Kushnick - Andre
- Brian J. White - Student #1
- Kelvin Yu - Keith Fannin
- Alan Charof - Driver
- Scott Paetty - Wade
- Chip Sickler - Vincent
- Kevin Weisman - Earl
- Daniel Raymont - Doorman
- Kelly Mantle - Drag Queen
- Jason Thompson - Jordan
- Elaine Kagan - Professor Mary Morton
- Ali Landry Monteverde - Natalie
- Austin Tichenor - Samuel
- Judith Drake - Minister
- Stephen Grove Malloy - Friend #2
- Ana Cristina Oliveira - Brigette Pastercheck
- Lara Del Arte - Diner
- John Ritter - Mr. Andrew Covington
- Sarah-Jane Potts - Molly
- Gerald W. Abrams - Judge David Amann
- Cameron Zeidler - Trent
- James Carpinello - Randy
- Nate Dushku - Reims
- Matt Doherty - Computer Guy
- David Smigelski - Casey
- Philip Boyd - Nick
- Carl J. Johnson - Peter
- Phillip Geoffrey Hough - Jason
- Jim Jansen - Dr. Leonard
- Francesca P. Roberts - Clinic Worker
- Arthur Taxier - Rabbi Morgenstern
- Nicki Micheaux - Al-Anon Leader
- Jenica Bergere - Patty
- Richard Erdman - Howie
- Val Lauren - Lou
- Eddie Cahill - James
- Colleen Crozier - Precious
- Scott Adsit - Professor Howard Morrison
- Michael Brager - Dirk
- Alex Nesic - Joe
- Nick Toth - Professor Boyden
- Juanita Jennings - Pastor Cathy
- Steve Eastin - Fire Marshal Howard
- Tony Guma - Dino
- Frank Crim - Dad
- Wesley Singerman - Oscar
- Jesse David Corti - Trevor McKinley
- Kristin Lehman - Avery Swanson
- Tyler Christopher - Clubgoer
- Daphnée Duplaix Samuel - Samantha
- Jonathan Adams - Paramedic
- Greg Collins - Bouncer
- Joy Gregory - Ann Kring
- Gregg Perrie - Roan Perets
- Jodi Bianca Wise - Cecelia
- Elizabeth Keener - Chris
- Kenan Thompson - DeForrest Ingram
- Elena Evangelo - Sharon
- Kristen Cloke - Rabbi Marisa Levin
- Ana Harrison - Customer
- Teri Garr - Dr. Zwick
- Brynn Thayer - Mrs. Crane
- Akiva Goldsman - Guest Speaker
- Jim Ortlieb - Professor Bill Hodges
- Rick Worthy - Jeremy Cavallo
- Kirk Baily - Financial Aid Officer
- Al Fann - Uncle Harold
- Alan Blumenfeld - Manny Blumberg
- Christopher Gorham - Trevor O'Donnell
- Allyce Beasley - Sharon
- Michael Chieffo - Natalie's Lawyer
- Brad Grunberg - Joey Blumberg
- Charley Rossman - Repo Man
- Cerina Vincent - Denise Jensen
- Joyce Brothers - Judge
- Candace Kita - Contestant #1
- Ashley Yegan - Contestant #2
- Wayne Thomas Yorke - Hair Stylist
- J.A. Popovec - Pageant Contestant
- Ashley L. Anderson - Pageant Contestant
- Karen Elmore - Dancer
- Sandra McCoy - Pageant Contestant
- Lionel Richie - Self
- Shannon Whirry - Barb Jones
- Meredith Bishop - Samantha
- Jane Daly - Kathy Lindstrom
- Bette Ford - Professor May
- Randy Kovitz - Doctor
- Anel Lopez Gorham - Princess Leia
- Frankie J. Allison - Scalper
- Lisa Edelstein - Lauren
- Ashlee Levitch - Tammy
- Julieanne Steger - Gaby
- Erick Avari - Dr. Ansari
- Bethany Joy Lenz - Gretchen
- Travis Wester - Student
- Dee Wallace - Allison Covington
- Christopher Allport - Dominic Webb
- Tait Smith - Nick
- Wen Yann Shih - Waitress
- Daniela Amavia - Dana
- Jason Ross-Azikiwe - Locksmith
- Shawn Hatosy - Owen
- Bitty Schram - Rita
- Richard Masur - Dr. Auerbach
- P.J. Marino - Customer
- Kala Savage - Lila Rotundi
- Kyle Davis - Student
- Jack Hannibal - Dennis
- Michael Kostroff - Bill
- Stanford Chase - Dancer
- Saxon Trainor - Gallery Woman
- Alyson Reed - Acting Professor
- Patrick Cavanaugh - Student #1
- Adam Harrington - Student #2
- Derek Richardson - Adam Davis
- Joel West - Rocco
- Dean Cameron - Jeff Marshall
- Anthony DeSantis - Chris
- T.J. Hall - Oscar
- Corena Chase - Jessica
- Adria Dawn - Pauline
- Joel Hurt Jones - Father
- Michael B. Silver - Michael
- Leila Kenzle - Attorney
- Jane Lynch - Professor Carnes
- Patrick Thomas O'Brien - Dan Waldron
- Pamela Roylance - Client
- John Prosky - Dr. Stern
- Vickilyn Reynolds - Nurse Jones
- Nicole Randall Johnson - Resident
- Joyce Guy - Headmistress
- Danielle Kirlin - Flight Attendant
- Annie Coffey - Graduating Student #2
- Erinn Bartlett - Claire
- Robert Sudduth - Scotch
- Randee Heller - Psychiatrist
- Susan Barnes - Nurse Gregory
- Louis Mustillo - Lie Detector Administrator
- Sonya Eddy - Cop
- Kurt Fuller - Paul Korsikoff
- Dane Hanson - Not Ben
- Ron Howard
- Matt Reeves
- Brian Grazer
- Tony Krantz
- J.J. Abrams
- Marcia Shulman
- Amy Jo Johnson
Elya Baskin interpreta a Bela en la serie.
Juan Fernández hace el papel de Dennis.
Evan Jones interpreta a R.A. #1 en la serie.
Michael Peña interpreta a Brian Burke en la serie.
Brian Howe interpreta a Eric Scott en la serie.
David Proval interpreta a Mr. Kinney en la serie.
Keri Russell interpreta a Felicity Porter en la serie.
Scott Speedman hace el papel de Ben Covington.
Tangi Miller interpreta a Elena Tyler en la serie.
Greg Grunberg interpreta a Sean Blumberg en la serie.
Capítulo disponible en las siguientes plataformas:
