Hospital buildings in Lincolnshire have a backlog maintenance bill of £236 million and still require capital funding for proposed changes to services.
Health bosses said the cost was for all sites in the county and that it is “rising year on year”.
They added that the cost was a result of “two decades worth of underinvestment” and that a plan was in place to make hospital estates “efficient”.
In addition, officials still require £81 million as part of plans to shake up health services in the region.
The proposals include changes at hospitals in Lincoln, Grantham and Boston.
Officials from Lincolnshire Sustainability and Transformation Partnership said they wanted to make local health service buildings “fit for purpose” and environmentally sustainable.
Sarah Furley, programme director for the Lincolnshire STP, said some of the county’s hospital sites were “over 100 years old”.
“If we meet that bill it will not give us buildings that are fit for the future, they will only be fit for today,” she said.
“If we want to have buildings that are fit for the future then, we require collegiate support across the system.”
She added that the STP has an estates plan in place to deal with the backlog cost and improve its buildings.
Among the proposals is to focus on corporate and administrative sites, such as trust headquarters, to move staff to other buildings in order to “improve multi occupancy” and reduce costs.
Meanwhile, Councillor Carl Macey, chairman of the Health Scrutiny Panel for Lincolnshire, said it was difficult to see how health officials would meet the backlog bill.
“It’s not a number that we haven’t heard before, but it is a massive amount of money and that is only to get it to a reasonable standard,” he said.
“It’s quite hard to see how they are going to achieve this, we would hope that they would get that funding into place.
“However, it is a case of seeing what happens over the next few months.”
Lincolnshire STP earlier this year failed in a bid for capital funding which would have reduced the bill for a shakeup of services.
Among the suggested changes are consolidating breast services at Lincoln County Hospital and introduction of urgent treatment centres.
The STP needs to show it has funding in place for its plans before it can go to public consultation on the acute services review.
A Freedom of Information request showed that health bosses had bid for £125.1 million from government and NHS England.
Of that number, just £45.9 million was handed to trust officials.
Most of the lost funding was for “STP estates wave four” funding and related to work for resuscitation and urgent treatment centres at Boston and Lincoln, as well as digital infrastructure and diagnostic sustainability.
In August, Prime Minister Boris Johnson announced £21 million for Boston Pilgrim Hospital’s A&E department which reduced the capital bill from £102 million.