The Defense Department today removed the University of Phoenix from the probationary status it was placed on a few months prior, making one of the nation's largest schools for military tuition assistance once again eligible to accept new students using that benefit.

"The Department determined that the removal of probationary status was warranted based on the department's internal review, the university's response to the department's concerns ... the active engagement and cooperation by representatives of the University of Phoenix and other relevant materials," a Defense Department statement said.

The statement added that the schools "will be subject to a heightened compliance review for a period of one year following the removal of probationary status." Should the Defense Department find additional problems, the school may end up on probation again.

The Defense Department placed the school on probation Oct. 7. Department officials gave no explanation for the action other than "reports of non-compliance," but Military Times obtained a letter that cited reasons behind the action.

That letter referenced Phoenix's past misuse of official military trademarks and seals, as well as instances of the school gaining access to bases and installations without giving notice to the proper military officials throughout the chain of command, as rules require. The letter acknowledged that these problems had already been addressed to DoD's satisfaction but also cited ongoing investigations of the school being conducted by other organizations, including the state attorney general of California and the Federal Trade Commission.

The probation was applauded by critics of Phoenix and other for-profit schools. But the school and its supporters questioned the merit of taking action against the institution for problems that have been fixed and investigations that remain uncompleted.

With today's action, the school is now immediately able to accept new military tuition assistance students and to gain access to military bases, as it was able to do before DoD took action in October, the Pentagon confirmed.

School President Timothy Slottow responded with the following written statement: "Our commitment to compliance, transparency and continuous improvement remains constant and we are grateful to leaders at the Department of Defense and in Congress for supporting a clear process and high standards from all educational institutions, and for ensuring military students are able to use their educational benefits for career-relevant programs at University of Phoenix."

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The University of Phoenix enrolled about 9,400 TA students, who took nearly 28,000 courses at a cost to the government of more than $20 million, in fiscal 2014, according to Defense Department information. That year, the most recent for which data is available, Phoenix enrolled the fifth-most TA students of any school nationwide.

The school has an even bigger footprint among veterans. In fiscal 2014, more than 49,000 students used the Post-9/11 GI Bill at the school, at a cost of more than $344 million. No other school came close to those figures. The entire California Community College system, which collectively enrolled the second-most Post-9/11 students, had fewer than 20,000 students.

The Veterans Affairs Department, which oversees the GI Bill, has taken no action against the school.