Guest Stars Will Chase as Michael Friedman Mare Winningham as Diane Mallum Phillipa Soo as Amber Collins Ray McKinnon as Jerry Mallum Brendan Patrick Connor as Howard Udell Raúl Esparza as Paul Mendelson Andrea Frankle as Beth Sackler Arischa Conner as Leah Turner Linda Powell as Karen Moles Rebecca Wisocky as Cynthia McCormick Aaron Serotsky as David Haddox Nicholas Logan as Walt Frank Wood as Doctor Trevor Long as Rudy Giuliani Co Starring R. Keith Harris as Martin Willis Morgan Brown as Gregg Wood Vince Pisani as David Gauvin Terrence Clowe as Cali Kire Elsasser as Lucas Joe Knezevich as Matt Erickson Rose Bianco as Therapist Lowrey Brown as Rehab Counselor David Alexander as Jay McCloskey Patrice Fisher as Methadone Clinic Nurse Charles Green as Betsy's Pastor Parker Sack as Dirk Shelly Townsend as Vivian Ben Peck as Asa Hutchinson Tommy McNulty as Bro Rep Rabon Hutcherson II as Purdue Rep #1 Athena McDowell as DEA Lab Analyst Annie Humphrey as Chemist Kyle Findley as Rehab Resident #2 Ja'Corey Jones as Rehab Resident #3 Jay Thompson as Kentucky Pharmacist Travis John Powers as Rehab Patient / Resident #1