Lance Stephenson scored 25 points, Paul George added 24 and the Indiana Pacers used a late run to hand the Sixers yet another loss, 99-90, on Monday.
Philadelphia's current 21-game skid is the fifth longest in NBA history and is five away from matching the 2010-11 Cleveland Cavaliers' record of 26.
The Pacers, winners of four straight on the heels of a four-game slide, made up for a mediocre 38.3 percent shooting effort by making 31 of their 38 free throws. The Sixers, by comparison, connected on 11-of-20 from the stripe.
The Sixers were within three twice in the fourth quarter, and Carter-Williams missed a potential tying 3-pointer with just over two minutes to play.
George Hill quickly put the Pacers on top 91-85 with a corner triple following the miss, and after Carter-Williams turned the ball over, Roy Hibbert pulled down an offensive rebound and got his putback to fall while being fouled.
The subsequent free throw made it a nine-point game with 1:23 showing, and a thunderous dunk by George over Henry Sims the next time down sealed the win.
The Sixers actually led by as many as nine in the opening quarter and owned a 24-21 lead prior to the Pacers going off for 37 points in the second stanza.
Stephenson netted 11 points in the frame, which ended with the Pacers scoring 10 of the final 12 points to take a 58-50 cushion into the break.
Philadelphia went back in front midway through the third, but Indiana again finished strong behind an 8-2 run that made it 75-67 in favor of the hosts heading to the fourth.