With all three rating agency verdicts now in, City Council members spent part of Wednesday’s meeting lauding the fiscal policies that led to the new ratings.

After Fitch Ratings last week released its upgraded AA+ rating, Standard & Poor’s Ratings Service also raised its rating one notch to AA+. Moody’s maintained its Aa2 rating for the city.

The new ratings apply to more than $100 million of new and refunded debt.

Councilman Michael Duman jokingly estimated that the upgrades would save the city “zillions” of dollars. The ratings work in a similar way to an individual’s personal credit rating — the higher the rating, the lower the interest rates that can be obtained on debt.

In reality, said financial adviser David Rose with Davenport & Co., the amount of the savings will be in the millions, though he could not yet give exact figures.

The rating agencies unanimously said the upgraded or stable ratings were based on the city’s financial improvements over the last four years.

“We believe the city’s significant improvement to its financial position, coupled with increasing reserves and now formal and sustainable fiscal policies, provides rating stability,” said Standard & Poor’s credit analyst Danielle Leonardis in a report.

The city’s new bonds, which will be used to fund a new municipal center and public utility projects, will be sold Thursday unless anything goes wrong, Rose said.

Moody’s, the agency that maintained its rating at Aa2, commended Suffolk’s progress in several areas but noted that “future expansion could once again pressure the city with increased demand for infrastructure and services,” though growth is limited right now because of the economy.

Rose told City Council members it would likely be at least three years before the city would see a hike to AAA, the highest rating given to any municipality.

“We are now at the precipice of AAA,” Rose said. “All cylinders have to be met. They have to really believe all the progress you made will continue.”

Vice Mayor Charles Brown praised the performance of City Manager Selena Cuffee-Glenn and her staff in keeping in line with fiscal policies.

“Good things just don’t happen,” he said. “They happen because you plan well and execute well.”