In a recent phone conversation from Chicago with Schumann and Miles Teller, who plays the soldier in the film, the answer is simple.
"I think, 'Welcome home' is the best thing you can say to anybody," Schumann said.
Teller added that there are other ways to respond to veterans, too; something that he gained insight by working on the film.
Teller realizes that sometimes asking about military service is a difficult subject to broach with veterans, particularly for those who served in wars prior to Iraq and Afghanistan.
Hall, who also tapped into the nerve of the subject matter with his Oscar-nominated screenplay for "American Sniper," very much did the same with "Thank You for Your Service," Schumann said.