In Season 4 as a way to be "more European" and sexually adventurous Dennis invited Jan to be his new roommate after Mac fakes his death, but he was quickly asked to leave after setting Dennis up to use a glory hole with Frank. ("Mac and Charlie Die (Part 2)")
During a brief "break up" in Season 5 Mac moved out of the apartment and moves in with Frank and Charlie. Eventually the two reconciled. ("Mac and Dennis Break Up")
In Season 6 Dennis kicked Mac out to move his wife Maureen Ponderosa in. According to Dennis Mac's name was not on the lease because of his bad credit. Supposedly none of the furnishings belonged to Mac either. ("Mac Fights Gay Marriage") Mac moved back in after Dennis and Maureen divorce. ("Dennis Gets Divorced")
During the Thanksgiving dinner The Gang held to "squash beefs" with some of those who held grudges against them, Frank started a fire by intentionally burning the rent money he owed his landlord Hwang in front of him. The fire spread, and The Gang fled the burning apartment after sealing all their guests inside. ("The Gang Squashes Their Beefs")
In Season 10 it is revealed that the apartment did burn down, and Mac and Dennis are now living in Dee's apartment. ("The Gang Spies Like U.S.") In the Season 10 finale Dee manipulates members of the cult that Dennis has started into fixing up the apartment, but when one of the cult members sets himself on fire at Dennis' command, it starts another fire that looks like it will again burn down the apartment. ("Ass Kickers United: Mac and Charlie Join a Cult")
In Season 11 Dennis commiserates losing the rent-controlled apartment. He and Mac move to a house in the suburbs for a month before moving back in with Dee and their new roommate, the Old Man. ("Mac & Dennis Move to the Suburbs")
In Season 12, the apartment is shown in its original form in Mac's dream. ("PTSDee") Apparently, Mac had won a bet against Dennis and was in control of refurnishing their fixed apartment; he elected to meticulously replicate their old apartment down every single knick-knack, which Dennis finds disturbing. The only notable difference in this new apartment is that Mac's old room is completely unfurnished, save for the Ass Pounder 4000 and a few towels. Mac assumed that he and Dennis would now share the latter's bed due to having shared a bed for a year. ("Dennis' Double Life")
Physical Layout and FeaturesEditDennis and Mac's apartment is much larger than Charlie's apartment, but slightly larger than Dee's apartment. It primarily has three rooms that you see, the main room of which has various workout equipment, a couch and a TV ("The D.E.N.N.I.S. System") and other furnishings. A bathroom is located in Dennis' room; it is a standard setup with shower, toilet, and sink. ("The Aluminum Monster vs. Fatty Magoo") The door in Mac's room may lead to another bathroom of his own, though this is not entirely certain.
Mac's room, to the left, is quite smelly due to his dirty socks and locked window ("Mac's Banging the Waitress") and is moderately messy and small. It is also lightly furnished with only a bed, a table, and a bookcase, all of which are completely bare and empty. The few decorations he has consist of various religious knick-knacks. Frank describes the motif as "prison cell". ("Mac Is a Serial Killer") Dennis' room, on the other hand, is huge and richly furnished with many decorations and items, including a TV on top of a large dresser, a king size bed, a CD rack, a chest of drawers full of sex tapes, and a bookshelf filled with various items. According to Dennis, he owns everything in the apartment. ("Mac Fights Gay Marriage")
Dennis has a collection of sex tapes of his various conquests at his apartment. ("Mac's Banging the Waitress") ("Dennis Gets Divorced") It is stated that Dennis is constantly video recording everything that goes on in his bedroom. ("Charlie and Dee Find Love")
- Season One: Charlie Has Cancer, Charlie Got Molested
- Season Two: Dennis and Dee Go on Welfare, Mac Bangs Dennis' Mom, The Gang Runs for Office
- Season Three: The Aluminum Monster vs. Fatty Magoo, Frank Sets Sweet Dee on Fire, Sweet Dee's Dating a Retarded Person, Mac Is a Serial Killer
- Season Four: Mac and Dennis: Manhunters, Mac's Banging the Waitress, Mac and Charlie Die (Part 2), Who Pooped the Bed?, Sweet Dee Has a Heart Attack
- Season Five: Paddy's Pub: Home of the Original Kitten Mittens, Mac and Dennis Break Up, The D.E.N.N.I.S. System
- Season Six: Mac Fights Gay Marriage, Dennis Gets Divorced, Mac's Big Break, Mac's Mom Burns Her House Down, Dee Gives Birth
- Season Seven: How Mac Got Fat
- Season Eight: Charlie and Dee Find Love, Charlie Rules the World
- Season Nine: Mac and Dennis Buy a Timeshare, Mac Day, The Gang Squashes Their Beefs
- Season Ten: Ass Kickers United: Mac and Charlie Join a Cult
- Season Eleven: Mac & Dennis Move to the Suburbs (mentioned only)
- Season Twelve: PTSDee, Dennis' Double Life
- Season 13: The Gang Makes Paddy's Great Again, The Gang Escapes, Charlie's Home Alone, Mac Finds His Pride
- Season 14: The Gang Gets Romantic, The Gang Chokes
- The lease on this apartment was signed only to Dennis - because Mac's credit history was too bad. ("Mac Fights Gay Marriage")
- We know that Frank pays the rent on the apartment he shares with Charlie (based on an arrangement they make in "Charlie Gets Crippled", and he pays the rent on Dee's apartment (Dee tells him he is way behind on her rent in the episode "The Great Recession"), but it is never stated whether or not he pays the rent for Dennis and Mac's apartment. Dennis' Double Life suggests he may have some role of financier, as Mac has access to enough funds to completely refurnish it.
- Charlie has been known to pee in his sleep and ruin their couch when he sleeps over at their apartment. ("Mac's Banging the Waitress")
- Dennis' bathroom has only ever made one physical appearance in the episode "The Aluminum Monster vs. Fatty Magoo". The doorway can be seen over Mac's shoulder in "Dee Gives Birth", and several people over the course of the series have exited Dennis' room after using the bathroom.
- Mac refers to it as "your bathroom" to Dennis in "The Gang Gets Romantic", which could imply there is a second one (or that Dennis is simply possessive of it). Further taking into consideration the layout of the walls of the apartment visible as charred remains in "Ass Kickers United: Mac and Charlie Join a Cult", the unexplored door in Mac's room, and Dennis and Mac's insistence on having two bathrooms in "Mac & Dennis Move to the Suburbs", it is highly likely that Mac has a bathroom of his own.
- Exterior shots of the apartment were taken in the Italian Market, South Philadelphia, 904 South 9th Street.