WASHINGTON—As the nursing workforce expands and baby boomers retire, the need for educators who are willing to train those new nurses is higher than ever.

Nursing educators instruct students both in the classroom and in clinical settings. The number of nursing students has increased significantly in the 21st century. The number of registered nurses taking the NCLEX-RN licensing exam annually doubled from 70,000 in 2001 to 140,00 in 2011.

As applications pour into nursing schools around the country, many find they do not have enough faculty members to admit all of their qualified applicants.

Part of what keeps nurses from faculty positions is the opportunity for a higher salary within the health care system.

“Theres’s a lot of competition out there for nurses with the highest level of education,” in the private health sector, Rosseter said. “It’s often hard to compete with that.”

The need for faculty increases as programs get more advanced. The National League for Nursing found that 57 percent of doctorate programs and 36 percent of master’s degree programs for nurses could not expand their student capacity in 2012 due to faculty constraints.

This happens in part because the more advanced the program, the more specialized an instructors’ skills have to be, said Robert Rosseter of the American Association of Colleges of Nursing. “You really need to have someone with a very specific skill set,” Rosseter said. “And those are often hard to find.

Dr. Peter McMenamin, senior policy fellow at the American Nursing Association, said colleges are simply not paying their nursing program faculty enough. “You have to have really a calling to want to be a faculty member taking a … pay cut,” McMenamin said.

Suzan Paxton, the clinical coordinator of the nursing school at Florida Southern College, said the pay cuts are highly prohibitive for nurses. ““Once you get out, you don’t get paid as much,” said Paxton, who was a nurse for 35 years. “You have to get into (teaching) just for the love of it.”

Paxton went into education because she wanted to stay in nursing, but did not want to do the 12-hour clinical shifts anymore. “It’s a very difficult physical job,” she said.

The need for nursing educators becomes more urgent as many in the field retire. Not many new nurses entered the field at the end of the 20th century, creating an age gap in the workforce.

As the baby boomer generation of nurses retires, “It’s gonna hit big time,” Paxton said.