A major work stoppage that has agitated the nation’s largest not-for-profit medical provider for nearly a month is set to end following productive negotiations, labor leaders said Monday.

The healthcare union representing the 31,000 workers involved in the strike said there had been “significant movement” at the bargaining table over the weekend, and as a result, union leaders decided to notify Kaiser that workers would return to hospitals and healthcare facilities at 7 a.m. Tuesday.

“[R]eturning members to their patients and their livelihoods is the clearest path to securing a final agreement and building on the progress achieved during the strike,” the United Nurses Assns. of California/Union of Health Care Professionals, or UNAC/UHCP, said in a statement Monday.

Kaiser said it could not immediately provide a response on the strike’s end.

Tens of thousands of Kaiser Permanente workers, including registered nurses, nurse anesthetists, pharmacists, midwives, physician assistants, rehab therapists, speech language pathologists, dietitians and other specialty healthcare professionals, walked off the job Jan. 26 in an open-ended strike.

The union launched the strike amid stalled contract negotiations, and over allegations it filed in a federal unfair labor practice charge that Kaiser had unlawfully undermined negotiations and attempted to intimidate workers by warning them about the consequences of striking and directing their peers to report union activity to management.

UNAC/UHCP said the healthcare system had neglected discussions over employee burnout and patient safety and unilaterally halted bargaining in mid-December. Kaiser ended talks both with a national coalition of unions representing Kaiser workers — called the Alliance of Health Care Unions, which usually leads negotiations on wages — as well as with local chapters, which preside over bargaining on scheduling and other contract terms specific to union members’ various regions and roles.

The Alliance of Health Care Unions counts some 62,000 Kaiser workers across 23 local unions among its members. UNAC/UHCP, which represents workers in California and Hawaii, is the alliance’s largest unit.

Bargaining over local contracts soon resumed after the lull, with UNAC/UHCP saying in recent days that “real progress” had been made and many “conceptual agreements reached” in negotiations over 15 local agreements covering thousands of healthcare workers.

Kaiser had previously called the strike “unnecessary” and filed a lawsuit in January days before it was set to begin. In the lawsuit, Kaiser argued that UNAC/UHCP was not acting in good faith and accused the union of attempting “to coerce concessions” by compiling and threatening to release a report describing alleged unethical and unsafe practices by the company.

The report noted that the Oakland-based healthcare system’s corporate pension, Kaiser Permanente Group Trust, holds assets in CoreCivic and the GEO Group, the two largest for-profit prison corporations in the U.S. After the report’s release in mid-January, state Assemblymember Liz Ortega (D-San Leandro) introduced Assembly Bill 1799, which would require nonprofit health plans that receive significant state subsidies to disclose direct and indirect investments, including holdings tied to private prisons and immigrant detention.

Kaiser did not immediately respond to a request for comment regarding its stance on the bill.

Anjetta Thackeray, a spokesperson for UNAC/UHCP, said Monday that Kaiser had yet to resume negotiations with the national bargaining table and that there were still many issues to resolve. But she said that because the union had “succeeded in bringing back serious negotiations,” it was important to get “members back to caring for patients and serving communities.”

“The statement had been made. … Members were able to shine a light on some issues,” Thackeray said. “We can’t call [the talks] closed just yet, but they are very, very close.”

Thackeray said she couldn’t yet provide details on pay or other agreements reached.

A flashpoint had been the union’s request for raises of 25% over four years, arguing that the wage boosts are necessary to compensate for the far smaller increases workers received following previous contract negotiations in 2021, when they received a 2% raise in the first year. Kaiser said it had proposed 21.5% wage increases, describing it as its “strongest national bargaining offer ever.”

The cooling down in labor tensions comes even as other Kaiser workers pursue work stoppages.

About 2,400 mental health therapists, social workers and psychologists for Kaiser patients in the Bay Area, Central Valley and Sacramento, for example, announced Monday they had authorized a one-day strike — citing issues with the way Kaiser triages its mental health patients, using telephone operators and artificial intelligence instead of human therapists. A strike date has not yet been scheduled.