Among the short films that Macneill has both directed, produced, co-wrote, and edited include the award winning short film Late Bloomer, which screened as an official selection at the 2005 Sundance Film Festival. It won the audience award at the 2004 Lake Placid Film Festival, and was screened at film festivals worldwide
Macneill lives in New York City, New York. He was the recipient of a 2009 Jerome Foundation Grant.
Macneill has written, produced, edited, and directed a number of short films before The Boy. Among them is a 2011 short Henley, which won a "Best Short Film" award at the 2011 Gen Art Film Festival Film Festival and the 2012 Carmel Film and Arts Film Festival. Henley was one of 64 short films selected from 7,675 submissions to screen in competition at the 2012 Sundance Film Festival.
Macneill directed and co-wrote the 2015 feature film The Boy, starring David Morse, Rainn Wilson, Jared Breeze, Mike Vogel, Bill Sage, Zuleikha Robinson, and Aiden Lovecamp. The film was produced by Elijah Wood, Daniel Noah, and Josh C. Waller and the company SpectreVision.
Macneill directed Lizzie, a psychological thriller starring Chloe Sevigny and Kristen Stewart. Lizzie is premiering in the U.S Dramatic Competition section at the 2018 Sundance Film Festival.