The new Frome Health Centre is due to open on Tuesday, January 2.
Once open, the existing surgeries at Park Road and Saffron on Berkley Road will close. The Locks Hill Surgery is unaffected and is to remain open as normal.
When the £10.5 million health centre, next to the hospital at Enos Way, opens its doors to patients in the new year, the full range of services will be available.
In addition to the medical teams, the building will also house a pharmacy, optician and a cafe as well as an operating theatre.
An open day is being held on Saturday, December 29, for people to have a look around before the official opening.
Partner in the practice, Dr Mark Vose said: "Our contractors, Interserve Construction Limited, have been doing a great job to ensure that everything is going to be completed on time and I can say with confidence that next door to the community hospital, Frome is going to have a medical facility that will be the envy of every other town."
He added: "Everyone working at the Frome Medical Practice is very excited about moving into such a fantastic building.
"However, the building is there for the people of Frome. We want all of our patients to see for themselves what they can expect at their new health centre."
Full times and details of the open day will be announced next month. At that time the practice will also be giving details of the final closure dates for the surgeries at Park Road and Saffron.
Dr Vose said: "Whilst everyone is very much looking forward to the move, it is also a huge undertaking.
"We would therefore ask that we have everyone's understanding during the transition period."
The new health centre building will also be the new home to patients currently served by the Beckington Family Practice's Fromefield surgery at 8 Bath Road.
The new facility will be able to carry out minor operations and provide other medical treatment rather than patients having to travel to the Royal United Hospital in Bath.