Upper Hunter MP Michael Johnsen joined with Muswellbrook District Hospital health service manager Wendy Hordern to mark the occasion.

He said the new building was part of the $21.5 million Stage 2 Muswellbrook Hospital Redevelopment, which will provide a range of expanded and enhanced facilities and services to meet the healthcare needs of communities in Muswellbrook and surrounding areas.

"We are getting ready for the opening of our up-to-date clinical services building at Muswellbrook Health Service," Mr Johnsen said.

"The finishing touches are being applied on the new building and, following the commissioning process, we will be ready for the first patients in the coming week.

"The Muswellbrook Health Service building includes the main entry, reception and general admissions, medical imaging, NSW Health Pathology, oral health, infusion unit (including chemotherapy and blood infusions), renal dialysis and day surgery."

Mr Johnsen said there would be a staged relocation of departments from the existing premises, too.

"Those moving include reception/general admissions, medical imaging, NSW Health Pathology, infusion unit, renal dialysis and oral health (from the Muswellbrook Public School)," he explained.

"All other departments will remain in their current locations.

"This development was part of a commitment by the government to deliver for the people of Muswellbrook and our region.

"I am delighted that our local community will enjoy the benefits of this state-of-the-art medical facility.

"Refurbishment works are now occurring on parts of the existing hospital building, and will continue through to mid-2019.

"Once these are completed, the new building will connect seamlessly with the existing building."