Prosecutors announced the decision on Wednesday in Canon City, where high school students exchanged hundreds of explicit photos of students as young as eighth-graders.
Fremont County District Attorney Tom LeDoux had said previously that some students could have faced charges that would require them to register as sex offenders. But he also held out the possibility no one would be charged.
An unspecified number of Canon City High School students were suspended in November in the case, and the high school's football team forfeited its last game of the season because players were involved.