Moody’s Investors Service, a prestigious credit rating firm, affirmed the University of Chicago Medical Center (UCMC)’s bond rating in late December after previously threatening a downgrade, though the outlook remains negative.

Moody’s affirmed the UCMC’s Aa3 rating, the fourth-highest rating from Aaa. The bond rating reflects Moody’s confidence in UCMC’s ability to repay debt and can impact borrowing costs.

This avoided a further downgrade that a November 2013 Moody’s report said was “likely” if UCMC did not improve its “operating cash flow margin in the coming months.” The operating cash flow margin measures how efficiently a company makes money from its day-to-day operations.

This December’s report from Moody’s noted that the operating cash flow margin had improved. A statement from the UCMC credited the improvement to an effort to control costs and improve the efficiency of its supply chain management. The report said a downgrade might follow if UCMC does not further improve its operating cash flow margin, which the report characterized as still “thin” for the Aa3 rating level.

The UCMC statement noted that “our industry’s changing financial landscape…is resulting in falling levels of reimbursements to many health care providers.”

The statement also said the UCMC “does not comment on specific ratings or on our outlook,” but is “confident that our financial metrics will continue to be strong.”