Howard was assessed a technical foul with 10:19 remaining in the second quarter of Miami's 106-94 win over the Sixers after Haslem took exception with the way the eight-time All-Star battled for a rebound.
Both players initially earned technical fouls, and Haslem was hit with a second one and automatic ejection just moments later.
Haslem, 40, who's in his 18th - and likely last - season with the Heat, played just three minutes, scoring four points on 2-of-2 shooting.
NBA rules require that any coach or player who collects 16 technical fouls in a season is suspended one game without pay. Howard will serve his suspension when the Sixers host the Orlando Magic on Friday evening.