The retired pediatric neurosurgeon announced the shakeup -- which comes a month after several top staffers quit his campaign -- in a statement Thursday.
His campaign said staffers' responsibilities were shifting and the campaign's expenditures were being "reprioritized."
Carson spokesman Larry Ross said 50 people are being cut.
Carson told Fox News on Thursday that the staff reductions set his campaign up for an extended battle for the GOP nomination, all the way through the Republican National Convention.
"We will be able to continue the campaign until Cleveland, and I will make appropriate adjustments to make sure we can achieve the goal," Carson said.
The campaign announced the staffing cuts in a statement Thursday.
"A key tenet of Dr. Carson's philosophy and campaign is fiscal responsibility, to that end, he realized that the practices of the past had to be fine-tuned and refined in order to pave the way for a leaner and more efficient organization," Carson's campaign said in the statement, which wasn't attributed to any single staff member. "This is a common practice utilized to reduce risk and leverage opportunity -- whether in a campaign, the federal government or corporate America."
The statement continued, "This step in the reorganization involved many components; we realigned responsibilities, made changes to the campaign's infrastructure and reprioritized expenditures. These steps were made to wisely and prudently position the campaign for the coming months. Regrettably, this action is affecting various team members throughout the campaign, as the realignment of positions and responsibilities necessitated the reduction of personnel. Their hard work and dedication to the campaign is greatly appreciated, and will not be forgotten."
Carson spent the morning Thursday in Washington at the National Prayer Breakfast, an annual event that transformed him into a political figure three years ago when he slammed President Barack Obama as he sat a few feet away.
On Friday he will appear in Nashua for a campaign event BAE systems, a defense manufacturing company that is the second largest employer in the state. He will then and will hunker down there for debate prep with his aides ahead of Saturday night's debate.
Bass, who was at Carson campaign headquarters in Manchester, told CNN that Carson will "see it through to the end."
"Dr. Carson is listening to the Lord. When and if the Lord shuts the door on the campaign, he will listen," he said. "People from the political world do not understand this."
Former Carson campaign manager Barry Bennett quit a month ago, leading an exodus of 20 staffers -- including Carson's communications director and top policy aide.
Bennett complained publicly about the role of Armstrong Williams, Carson's business manager, who has no official role with the campaign yet Bennett said still seemed to have the candidate's ear.