Councillors have said progress has been made by Thames Ambulance Service since an improvement plan was put in place by Lincolnshire West Clinical Commissioning Group.
Thames won the contract to provide non-emergency patient transport for the region in July 2017 but was heavily criticised by staff and patients for its performance.
At a health scrutiny committee meeting held in December 2017, Lincolnshire county councillors gave a vote of no confidence in the service.
Lincolnshire West CCG handed the firm a remedial action plan which required Thames to improve its performance in 12 areas.
Recent performance figures show Thames improved in areas such as journey arrival times and fast track patient collections.
Carl Macey, chair of the Health Scrutiny Panel for Lincolnshire, said that he felt assured that Thames were moving forward.
He said: “I think that at the moment in time we have assurances that they are moving in the right direction.
“There are still some areas that still need to be carefully scrutinised and kept an eye on.
“It is a lot more positive since they came to us a matter of months ago.”
The committee moved to invite Thames before the panel on a quarterly basis rather than every month following the report.
Mike Casey, director of operations at Thames, said that progress still needs to be made at the firm.
“There is still much to do,” he said.
“The east of the county remains a challenging area for us and we have some work going on to find out how we can get to a better position there.”
Mr Casey previously apologised to patients and staff in Lincolnshire for its poor performance in the county.
Thames have since undergone a management restructure which includes Derek Laird, former commercial director of West Midlands Ambulance Service, taking over as chief executive.
The restructure also includes the introduction of a manager tasked with implementing recommendations made by the Care Quality Commission.
Despite the improvement in performance, Thames recently lost the contract for non-emergency patient transport in the north of the county.
North Lincolnshire CCG decided to cancel the contract and gave the firm 12 months notice.
In a statement, the CCG said that while improvements were seen with the service, patients were still “experiencing difficulty”.