Negotiators for Jackson Health System and SEIU Local 1991 agreed Tuesday to a contract that calls for $52 million in concessions for each of the next three years, but workers could get some of that money back if they find ways of saving the hospitals money or gaining new revenue.

The tentative agreement, after five months of hard-fought bargaining, will be voted on next week by the bargaining units covering nurses and other healthcare professionals. A third unit, covering physicians, was still in discussions with management late Tuesday afternoon.

The three-year contract means Jackson and the SEIU can avoid the messy impasse procedure that county unions recently went through in which, after agreeing to some cuts, they went before a bitterly divided county commission that imposed additional cuts after two tumultuous meetings.

The contract calls for union members to donate three percent of their pay toward their pension, as workers in the state retirement fund are doing. SEIU members will continue to shift five percent of their salary to fund their health insurance. They are giving up $1,000 a year that had been going to each worker’s health flex account, and their vacation time will be cut by five days a year.

Workers will not have automatic raises -- for merit or cost of living -- for the duration of the contract, but management’s announcement last fall of 10 days of required furlough was reduced to eight days and Jackson promised no more furloughs until at least October 2013.

The negotiations Tuesday did not include any mention of layoffs, which Chief Financial Officer Mark Knight said were a separate issue. Last week Chief Executive Carlos Migoya said there will soon need to be “significant” layoffs to “right-size” Jackson, which has lost $423 million the past three years.

For months, Martha Baker, president of Local 1991, said she would not budge on management’s demands that nurses’ schedules should be flexible, depending on how many patients were in the hospitals. Many hospitals send nurses home or tell them not to come in if they’re not needed. Under Tuesday’s agreement, union members will continue to have a guaranteed 40-hour work week.

Speaking to her union members at a meeting Tuesday afternoon, Baker emphasized a provision in which a union “efficiency task force” could find cost savings and new ways of gaining revenue. If the union finds $15 million in savings each year for Jackson, members can get back vacation time or other concessions.

“We found $10 million in savings last year,” Baker said, and she believes workers can do even better in such measures as decreasing length of stay or wait times in the emergency rooms. “We want to do what’s right for the patient, and we want to help save Jackson,” Baker said.

Nurses will continue to work three 11.5-hour shifts one week, and four 11.5 hour shifts the other week in a two-week pay period, which results in some built-in overtime in the second week. But under the new deal, they will not get overtime on a daily basis, meaning that if they work past the end of their shift on a three-day workweek, they will be paid at their regular hourly rate -- a key for managers trying to reduce overtime costs.

In other Jackson news:

• A poll of 800 Floridians sponsored by the Safety Net Hospital Alliance of Florida, which represents Jackson and other public hospitals, reports that 59 percent oppose “a plan to reduce state reimbursements to hospitals for healthcare services they provide to the poor and uninsured in order to help balance the state budget.”

The administration of Gov. Rick Scott and both houses of the Legislature are proposing cuts to the Medicaid program.

• Magdalena H. Averhoff, associate chief medical officer of Jackson South Community Hospital, has been appointed by Scott to the Florida Board of Medicine, which oversees licensing and discipline of the state’s doctors.