Fitch Ratings has renewed its “AA” rating on Maine’s outstanding general obligation bonds and its slightly lower “A+” rating on the Maine Municipal Bond Bank’s outstanding general resolution bonds.

A rating of “AA” is two levels below the best possible rating of “AAA,” and an “A+” rating is two levels below “AA.” Much like a consumer’s credit score, a state’s bond ratings determine its ability to borrow money affordably.

Maine’s moderately high ratings reflect the state’s responsive budget management and low overall debt outlook, along with its fiscal challenges such as below-average economic growth prospects and meager reserve funds, Fitch said.

“The ‘AA’ rating reflects Maine’s generally steady revenue performance and very manageable long-term liabilities, offset by persistent structural pressures, thin reserve levels and a relatively stagnant economic base,” the company said in a news release.

Other economic challenges for Maine cited by Fitch are its high median age, virtually nonexistent net population growth and flat-to-declining labor force.

Fitch is one of the “big three” credit-rating agencies recognized by the U.S. Securities and Exchange Commission, along with Moody’s and Standard and Poor’s.