Eric Gilliland was involved in writing and producing 111 episodes for seasons 5–8, beginning with the episode "Terms of Estrangement, Part 1", with his final episode as writer and producer being "Fights and Stuff".
He served as co-producer for the entirety of Season 5, he was subsequently promoted to supervising producer for the entirety of Season 6. He was than promoted to co-executive producer for the first 20 episodes of Season 7, thereafter he served as executive producer. He remained in this position until his departure from the series at the end of Season 8.
Throughout the series he wrote 11 episodes, writing the following:
- Season 5
- Season 6
- "The Mommy's Curse"
- "Lies My Father Told Me" (teleplay by)
- "Altar Egos"
- Season 7
- Season 8
- "The Last Date"
- "Another Mouth to Shut Up" (story by)
- "Fights and Stuff" (story by)