The cross is part of an emblem that includes the Latin words, "For God and humanity." It's been used by the Evans Army Community Hospital for more than 40 years. But the Military Religious Freedom Foundation said the emblem must be removed because it violates the separation of church and state.
"We think it's completely unconstitutional on one hand," said Mikey Weinstein, founder of the group, in an interview with FOX 21. "On the other hand, we believe it completely emboldens that we should be rightfully fighting."
Weinstein said dozens of soldiers have complained about the cross.
Lt. Col. Steve Wollman told the Associated Press Fort Carson commanders will review the complaint, but he noted that references to doctors serving God and humanity predate Christianity. Wollman adds that the cross is both an emblem of mercy and a symbol used by medieval pilgrims to mark their camps.
Weinstein disputes that argument - saying the cross is symbolic of the Crusades and could offend Muslims.
This continues to add more fodder to the argument that we are Crusaders," Weinstein told Huffington Post. "It's exactly what fundamentalist Muslims want."
"I would consider that to be unbelievable garbage and crap the pilgrims carrying those crosses were headed down the holy land and engaging in wholesale slaughter of Christians," Weinstein told FOX 21.
The phrase "For God and humanity" dates back to the Hippocrates, considered to be the father of western medicine.
Weinstein was recently successful in having Christian evangelist Franklin Graham banned from participating in an upcoming National Day of Prayer service because of comments he made about Islam.