Planning consent has been awarded to Millview Medical Practice on Sleaford Road in Heckington to take over and convert the disused police office next door.
The practice proposes to change the small local police station to provide an additional consulting room for surgery.
The proposal involves removal of the existing garage door and the replacment with a window.
North Kesteven District Council planning officers felt the external alteration to the building is of minimal impact to its surroundings or neighbours.
The practice, which also has a surgery in Sleaford, is currently undergoing building work for an extension to expand its premises at Heckington to cope with growing pressure of patient numbers.
Practice manager Marcus Griffen explained previously that the project is being partly funded by NHS England in response to expected population growth of the village and Sleaford.
He said: “There is a need for more patients to be seen, with the potential development of 500 new houses meaning an extra 1,500 patients in Heckington alone.”
The plan is to build a two storey extension on a grassed area between the existing building and the car park. It would provide two extra clinical rooms for doctors and practice staff, along with a new treatment room for nursing staff, freeing up the present treatment room for other purposes, including an extra waiting room.
Mr Griffen said the dispensary will be rebuilt and redesigned to better serve elderly patients.
The plan is to transfer Sleaford office staff to the Heckington site.
Work should be completed by the end of March 2016, although there has been some concern from the parish council about parking on the road while the car park is occupied by the builders.
The offer of adjacent land owned by the parish council as a temporary staff car park during construction has not been taken up as the ground had become too wet.