Nearly half of all nurses working in Sagadahoc, Lincoln, Knox, Waldo and Hancock counties are older than 55 and expected to retire or reduce their hours over the next 10 years, contributing to a drastic shortage that officials in Maine are trying to counter.

Earlier this year, a state study revealed that, without intervention, Maine could be short 3,200 nurses by 2025. An additional report released Thursday by the Maine Nursing Action Coalition identified counties with high percentages of nurses approaching retirement, turning attention to rural areas where the looming shortage could hurt the most.

“It is with an abundance of concern for our state and the patients in our care that we continue to sound the alarm about Maine’s nursing workforce cliff,” said Lisa Harvey-McPherson, a nurse and co-chairwoman of the Maine Nursing Action Coalition. “Every region of Maine and every health care setting faces challenges as our state ages and a wave of dedicated caregivers approaches retirement.”

To avoid the shortage, state officials say they need to boost the number of new registered nurses licensed in the state by 400 each year, producing a 65 percent increase in the number of nurses in the state. In addition, the state would have to recruit 265 RNs to move to Maine each year to avoid the shortage.

In Sagadahoc, Lincoln, Knox and Waldo counties, 49 percent of nurses are on the verge of retirement age. In Washington and Hancock counties, it’s 48 percent. The situation is only slightly better in southern Maine, where 40 percent of nurses in York and Cumberland counties — home to a third of the state’s nurses — are 55 or older. Aroostook, Penobscot and Piscataquis counties report 29 percent of nurses approaching possible retirement.

As Maine’s citizens age, the demand for health care is expected to boom. Maine’s senior population is projected to grow by 37 percent over the next 10 years, and many of them will face chronic health problems such as diabetes and arthritis. The nurses won’t be needed in only hospitals. Home health organizations and residential assisted-living facilities expect to have high demand for new workers.

“If we are going to address the challenges facing the nursing workforce across our state, it is imperative that we do so collaboratively,” acting Maine Department of Health and Human Services Commissioner Ricker Hamilton said in a statement.

On Oct. 27, the University of Maine System, Maine DHHS, and the Nursing Action Coalition will host a summit at the University of Maine in Orono. Health care providers, elected officials, philanthropic groups and higher education officials will look at the data, discuss the findings and vet strategies for countering the shortage.

Boosting the number of nursing graduates in the state is one of the first strategies being tackled. The University of Maine announced last week that its incoming nursing class would be 35 percent larger than the previous one in an effort to start closing the gap. The University of Southern Maine plans to expand its own nursing program, while the flagship campus is considering helping the University of Maine at Machias launch its own nursing program under their new partnership.

Follow Nick McCrea on Twitter at @nmccrea213.