Deacon asks Doug to come along to Atlantic City for a weekend. Carrie wants to go salsa dancing with Doug but concurs and they go to Atlantic City. However, Deacon has send a message that he won't be coming. Doug's boss on the other hand, did come to Atlantic City and Doug and Carrie don't seem to get rid of him.
When Doug and Carrie find an old check in a wedding present, they need to invite Doug's annoying relatives to write them a new one. The Heffernans plan on going to New Orleans with the money. However, Doug's relatives say that New Orleans is "their town", and tell Doug and Carrie not to go without them. Doug and Carrie get to the "Big Easy", but can they get back without them knowing.
Carrie's work has an annual golf trip, but Doug and Carrie used to always take Deacon and Kelly. Now that Deacon and Kelly have split up, Doug and Carrie have to try and find another couple to invite to the golf trip. But Deacon later meets a woman and now he can go on the trip and bring his new girl friend along too. Carrie meets his girlfriend and has a hard time clicking with her. Holly agrees to watch Deacon's kids, but she has to bring a reluctant Arthur along.
Doug and Spence have a high school reunion, but Spence doesn't want to go because he had a relationship that ended really badly. Doug is looking forward to it, until Carrie starts wearing a new hairstyle, which is a tight bun that looks like a librarian's hair. So now Doug is afraid that she will wear her hair like that to his reunion.
Doug and Deacon bet 100 dollars on a fight that they are not allowed to bet on. They win 5,000 dollars, and have to get rid of it quick or Carrie will know Doug disobeyed her orders not to take the money. Doug and Deacon decide to take off from work for a whole day and spend all the money. The money is spent on fancy dining, expensive cars, and a live living room performance by the 'money man' Eddie Money.
The fourth season concludes with Arthur visiting a psychiatrist and recalling via flashback a disturbing encounter with his dad that may explain Arthur's abrasive personality. Carrie and Doug decide to "validate" Arthur in everything he does. This leads to Carrie visiting the psychiatrist, who also has a flashback that makes her doubt her personality. Which leads Doug to also visit the psychiatrist and has his own flashback that makes him learn something about himself.
Holly asks Doug if she can get a raise for walking Arthur, while Carrie gets a promotion on being the project supervisor which changes her hours from 8 PM to 6 AM, so now Doug and Carrie get to hardly see one another. Doug also has trouble sleeping at night so he decides to use Arthur to solve his problems.
Doug and Carrie get new neighbors who are really clean cut and high class people. When they get to know them Carrie feels that she and Doug are below them. Carrie really begins to care on what they think about them. Arthur keeps thinking of sneaky ways to convince Spence in getting into the subway for free.
Deacon brings his son over to Doug and Carrie's house after foot ball practice, and Deacon begins to complain about how Kirby hates it. So Deacon asks Doug to help him teach the team. Doug begins to love the sport again...a little to much.