In July, Rawlings-Blake's administration proposed scaling back the free bus service, after the City Council declined to pay for it by increasing the parking tax at Baltimore's public garages.
The mayor said Friday the service will "likely" need to be reduced, but that she won't do it in the waning days of her administration.
"Any changes to the Circulator system will likely have a significant impact on the next administration's budget," Rawlings-Blake said in a statement. "I will present the next administration with the best and most current information to allow the next mayor to make an informed decision on the Circulator's future operations."
The mayor said her successor should partner with the Maryland Transit Administration, which is overhauling the city's commuter bus system under a program called BaltimoreLink.
She hopes a new service contract for the Circulator, currently under review, will "provide efficiencies to avoid implementing the proposed worst-case-scenario service cuts."
Once the bid process is complete, she said, the city will have a better idea how much the system will cost going forward. Veolia Transportation has run the Circulator since the service's inception in 2009.
Rawlings-Blake's initial proposal would have eliminated in January the Banner route between the Inner Harbor and Locust Point and would have canceled the northern expansion of the Purple route to the Johns Hopkins University, which began about a year ago.
After potential cuts were announced, the mayor said she "heard from passionate residents who want to keep the current Charm City Circulator system intact."
"I am proud of the service the Charm City Circulator provides and understand the concerns of the community if service must be cut," she said.
City Councilman Eric Costello cheered Rawlings-Blake's decision to delay potential cuts to the Circulator. The Banner route serves his district.
"The Circulator has been a shining example of how public transportation should work with reliable, safe, and clean service," Costello said. "It has been wildly successful and has converted many car-reliant residents into regular Circulator riders."
It's the second time Rawlings-Blake proposed cutting the bus service and then decided against it.
In May 2015, her administration proposed cutting the Banner route and reducing service on the Green and Orange routes, which connect East and West Baltimore to downtown. By July of that year, she announced plans to continue the service with far fewer reductions.
The mayor included $6 million in this year's budget that would pay to continue the routes, but the money was contingent on the City Council agreeing to a 4 percent increase in the parking tax.
Rawlings-Blake's administration introduced legislation to increase the tax in May. The bill has not received a hearing.
City Council President Bernard C. "Jack" Young and other council members have opposed the increase. Lester Davis, Young's spokesman, said there is "not a consensus on the council to move the piece forward." He said that when the parking tax was increased in 2013, the council agreed not to raise it again until 2020.
The Circulator costs the city about $14 million per year. It is funded by state and other grants, and by the sale of advertising on the buses. The system has also received federal funding. More than 4 million people use the Circulator each year.
City Councilman Brandon Scott has advocated charging $1 a ride to offset the service's cost. Opponents of that plan say charging fare would rob the Circulator of its appeal, causing ridership to decrease.
Democrat Catherine E. Pugh, Republican Alan Walden, Green Party candidate Joshua Harris and a slew of write-in candidates — including former Mayor Sheila Dixon — are running for mayor. Dixon launched the Charm City Circulator during her previous term.
Election Day is Nov. 8 and the next administration will take office in December. Rawlings-Blake did not seek re-election.