A penny is a one cent piece minted by the U.S. treasury.
Relevance to Scrubs
On J.D.'s second day at Sacred Heart Hospital, he comments to the Janitor who is repairing a door that it could be a penny that is stuck in the door. The Janitor then tells him "If I find a penny in there, I'm taking you down." Later, the Janitor shows J.D. that it was a penny, and says "I'm watching you!" ("My First Day")
Later on in "My Bright Idea" the illusion of a penny even gave J.D. a bit of relief: Turk offered the Janitor five dollars to eat a penny that was actually a tracking device used by J.D. and Turk to play an advanced variant of hide & seek.
In another season and episode, J.D. sets the Janitor a riddle to do. "What two coins when put together makes 30 cents, and one of them is not a nickel." The Janitor responds after researching at the library - a penny, and an out of mint coin which cost 29 cents to a collector. J.D simply tells him "A quarter and a nickel, because only one of the coins is not a nickel. The other one is." ("My Lucky Night")
In "My Musical", the Janitor sings (in The Rant Song) "It all started... with a penny in the door." Later in "My ABC's", the Janitor says he only hates people who wrong him like taking his things or putting pennies in doors. Both of which he has accused J.D. of doing.
In "My Finale", J.D. admits that on his first day, a penny fell out of his pocket and broke the door the Janitor was working on. The Janitor stated that he witnessed the event, but wanted J.D. to admit it as a "Test of Character". The Janitor continues on to state the J.D. had failed the test and thus missed out on a potentially wonderful friendship. The Janitor also proclaims that he kept the penny for over 8 years after making a necklace with a penny and harassing J.D. with it. However, some have pointed out that the date on the penny in the final episode shows 2006, leading us to believe that the penny is just another part of an elaborate game to annoy J.D. as the original penny would have had to be minted before 2001 when the show was filmed.
- J.D. has a fear of pennies, possibly due to this event.