Caroline Morse, an 18-year nurse practitioner at Massachusetts General Hospital, said she makes nearly the same amount — about $105 an hour — as a registered nurse with the same years of experience, just without the $130,000 of debt Morse took on for her additional training. At Dana-Farber, she would be making roughly $45,000 more per year, according to Morse and pay scales provided to the Globe.

“We’re sick of these discrepancies. I’m going to get lapped by my pay,” Morse said. “It’s so hard when you know you’ve dedicated your life to an institution and then this is the thanks you get.”

MGB is facing yet another round of growing pains as it tries to integrate its two flagship hospitals and position itself as a cancer powerhouse. A number of unionization efforts have materialized in the last two years, as primary care physicians, home care nurses, and occupational therapists demand higher pay and better working conditions. While some groups successfully voted to unionize, contracts have been harder to secure.

In a statement, an MGB spokesperson said the health system offers market-competitive pay and benefits for its nurse practitioners and physician assistants, together known as “advanced practice providers.” And they are seen as leaders and treated with respect, the spokesperson added.

“Advanced practice providers are vital to delivering high-quality care across our system,” the statement read. “We are committed to supporting [them] through competitive compensation, professional development, and a strong practice environment.”

The pay issues especially sting, the cancer clinicians said, because they know they do much of the same work as doctors, but with less training and smaller salaries. At MGB and elsewhere, nurse practitioners and physician assistants fill in crucial gaps in seeing patients.

“I am diagnosing, treating, prescribing very high-level medication, including narcotics,” Morse said. “My colleagues are prescribing chemotherapy agents. We are treating patients at the highest level of our scope.”

Morse and three other nurse practitioners interviewed by the Globe said job candidates have turned down offers to work at the cancer institute because they could make more elsewhere. One cancer institute nurse practitioner left for Beth Israel Lahey Health, where the pay is higher, Morse said.

The cancer institute has instead had to hire less experienced nurse practitioners, increasing the workload of the more seasoned clinicians because the newer providers can’t yet handle patients who are the sickest and have the greatest needs, clinicians said.

Mass. General Hospital nurse practitioners and physician assistants, who are not unionized, have had longstanding complaints about pay. They were initially left out of raises in 2024, when registered nurses at MGH were given 13 percent raises after unionized nurses at the Brigham secured a new contract with large pay bumps. After complaining to hospital administrators and contacting unions, the advanced clinicians received a 7.5 percent market adjustment and 2.5 percent merit raise. But the fix hasn’t kept pace with registered nurses’ subsequent raises, clinicians said.

“I’m getting 2.5 percent raises every year, which doesn’t even match inflation,” said one nurse practitioner, who, like two others, spoke to the Globe on condition of anonymity out of fear of retaliation. “So basically, we’re working for less.”

The three nurse practitioners said they also want more input into how the cancer institute should work as it expands.

MGB is expanding its own cancer institute anchored at its two flagship hospitals, Brigham and Women’s and Mass. General, as the Brigham’s longtime partner, Dana-Farber, prepares to break ground on a new cancer hospital it’s building with MGB rival Beth Israel.

MGB’s cancer investment includes renovations at Brigham and complements the ongoing construction of the $1.9 billion Phillip and Susan Ragon Building, which is expected to open in two phases in 2027 and 2030 on MGH’s main campus.

Because they are at the bedside, the nurse practitioners said, they have ideas for how care can best be coordinated across the center’s multiple sites.

A majority of the MGB Cancer Institute’s nearly 200 advanced practice providers filed a federal petition in January to hold a unionization vote and join the Massachusetts Nurses Association.

Now that vote is on hold. In an email last month to clinicians, cancer institute leaders said they had asked the federal board charged with supervising union elections to halt the vote, saying that nurse practitioners and physician assistants are different roles, so they can’t be part of the same union. The health system also took issue with the inclusion of only nurse practitioners and not all nurses at MGH.

MGB mounted a similar opposition against the proposed primary care doctors’ union.

“We are participating in the [National Labor Relations Board] process to seek clarity on these questions,” a spokesperson for MGB said.

The email was a semantic whiplash to the nurse practitioners, who were not considered nurses during the 2024 raises, even though nurse practitioners have to start their careers as registered nurses.

“Basically, they’re saying, ‘You’re not nurses when it’s not good for us, and you’re nurses when it is good for us,’” Morse said. “It’s a little bit shady.”

Cancer institute clinicians involved with the unionization effort said that MGB’s argument is meant to weaken the collective power of their potential union by reducing its size and adding administrative work.

“In our practice, the physician assistants and nurse practitioners have no difference, and MGB designed it that way,” Morse added. “I can call out and a physician assistant could fill my position no problem, no special approval needed.”

It’s not clear when the MGB Cancer Institute vote could be rescheduled, said Massachusetts Nurses Association spokesperson Joe Markman.

Sharon Block, executive director of the Center for Labor and a Just Economy at Harvard Law School and a former National Labor Relations Board member under President Barack Obama, said she couldn’t assess the validity of MGB’s argument against a cancer institute union. But, she said, the health system does seem to be taking a confrontational approach to unionization efforts, which she acknowledged is not uncommon among employers.

“There is a pattern that we’re seeing developing at MGB to be maximalist in their sort of litigating approach to their employees’ desire to unionize,” Block said. “Just because they can make an argument doesn’t mean that they should.”

The decision to unionize wasn’t an easy one, clinicians at the cancer institute said. Some said they had initially chosen to work at MGH because it wasn’t unionized, which meant fewer requirements about which shifts they would have to work. But conditions in the last few years have changed as MGH and the Brigham integrated care under their parent organization, MGB.

As the unionization process stalls, cancer center leadership internally announced “learning and listening” gatherings with nurse practitioners and physician assistants to discuss the future of the institute and to hear concerns. Nurse practitioners say it’s not enough.

Doctors at the cancer institute have been overwhelmingly supportive of providers like Morse, she said.

“They keep telling us, ‘What would we do without you?’” Morse said. “They know that their clinic can’t function without us.”

Marin Wolf can be reached at marin.wolf@globe.com.