In a 2010 interview with "Out" Magazine, Jesse Tyler Ferguson said that the running joke that Jay kept "forgetting" that his son, Mitchell, is gay (and Mitchell had to come out to his father repeatedly) is drawn from Ferguson's real life - he had to come out to his real father three different times over many years before his father actually believed it. When Ferguson told the show's writers this story, they found it very funny and decided to add it to Mitchell's backstory.
Phil's birthday is either on April 3rd or 30th (US release dates of the original iPads). This is due to a joke in which Phil says 'The iPad comes out on my actual birthday, it's like Steve Jobs and God got together to say "We love you, Phil"'
Nicole by O.P.I. has a line of nail polishes that are marketed and advertised in print as "inspired by TV's Modern Family". Their print ads feature Julie Bowen, Ty Burrell, Sarah Hyland, Ariel Winter and Nolan Gould in a family portrait group image.
Everytime DeDe (Jay's ex wife) comes to visit, she arrives at a different family household. In Season 1, she went to the Tucker-Pritchett's. In Season 2, she arrived at the Dunphy's. Then finally in Season 4, she came to the Pritchett's.