WASHINGTON — Senate negotiators announced on Sunday they had agreed on a bipartisan outline for a narrow set of gun safety measures with sufficient support to move through the evenly divided chamber, a significant step toward ending a yearslong congressional impasse on the issue.
The plan, endorsed by 10 Republicans and 10Democrats, would include funding for mental health resources, boosting school safety and grants for states to implement so-called red flag laws that allow authorities to confiscate guns from people deemed to be dangerous. It would also expand the nation’s background check system to include juvenile records for any prospective gun buyer under the age of 21.
Most notably, it includes a provision to address what is known as the “boyfriend loophole,” which would prohibit dating partners — not just spouses — from owning guns if they had been convicted of domestic violence. The framework says that convicted domestic violence abusers and individuals subject to domestic violence restraining orders would be included in criminal background checks.
The outline, which has yet to be finalized, falls far short of the sprawling reforms that President Biden, gun control activists and a majority of congressional Democrats have long championed, excluding a ban on assault weapons. And it is nowhere near as sweeping as a package of gun measures passed nearly along party lines in the House last week, which would bar the sale of semiautomatic weapons to people under the age of 21, ban the sale of large-capacity magazines and implement a federal red flag law.
But it amounts to notable, albeit narrow, progress, given the deep party divisions over how to address gun violence and repeated failed efforts to approve gun reform on Capitol Hill, where Republicans have thwarted action for years.
The backing of 10 Republicans for the outline announced on Sunday suggested that it could scale an obstacle that no other proposal currently under discussion has been able to: drawing the 60 votes necessary to break through a G.O.P. filibuster and survive to see an up-or-down vote on the Senate floor. Still, aides cautioned that until the legislation was finalized, it was not certain that each of the components could maintain that level of support.
Republicans balked in March at including a provision to address the so-called boyfriend loophole as part of a reauthorization of the Violence Against Women Act, forcing Democrats to drop it in order to pass that legislation.
The gun violence agreement was announced on the sixth anniversary of the mass shooting at Pulse, a gay nightclub in Orlando, Fla., where a gunman killed 49 people in what was then the deadliest shooting in modern American history.
“Today, we are announcing a common-sense, bipartisan proposal to protect America’s children, keep our schools safe and reduce the threat of violence across our country,” the 20 senators said in a joint statement. “Families are scared, and it is our duty to come together and get something done that will help restore their sense of safety and security in their communities.”
Negotiators must now translate the broad principles of the framework into legislative text, a far more fraught process, and secure enough support in both chambers for the legislation to become law.
Senator Chuck Schumer of New York, the majority leader, pledged to put the agreement up for a vote once the legislation had been completed, calling it “a good first step to ending the persistent inaction to the gun violence epidemic that has plagued our country.”
“After an unrelenting wave of gun-related suicides and homicides, including mass shootings, the Senate is poised to act on common-sense reforms to protect Americans where they live, where they shop and where they learn,” Mr. Schumer said in a statement. “We must move swiftly to advance this legislation because if a single life can be saved, it is worth the effort.”
Still, gun safety activists said they viewed the measures as meaningful progress that they hoped would mark a significant shift in how Republicans approached gun safety legislation moving forward.
“The fact that a group this large is coming together to get it done shows that we’re in a historic moment,” said T. Christian Heyne, the vice president for policy at Brady United Against Gun Violence. “It feels like a critical initial step for what I hope will be a new era in gun violence prevention.”
Mr. Heyne said that closing the dating partner loophole, in particular, has long been one of his organization’s key priorities. “All of these things individually are meaningful,” Mr. Heyne said. “When you look at them together, it feels pretty significant.”
John Feinblatt, the president of Everytown for Gun Safety, said if the framework announced was enacted into law, “it will be the most significant piece of gun safety legislation to make it through Congress in 26 long and deadly years.”
Some House Democrats said they were cautiously optimistic about the measures that were able to attract bipartisan support in the Senate.
“I’m disappointed to hear a focus on increased criminalization and juvenile criminalization instead of really having the focus on guns,” Representative Alexandria Ocasio-Cortez, Democrat of New York, said on CNN’s “State of the Union.” “But the background checks provision is encouraging. So I think we really need to look at the text.”
Representative Jamie Raskin, Democrat of Maryland, said the legislation fell short of the sweeping actions necessary to prevent mass shootings. But he said he would work with the modest deal being forged in the Senate. “It’s moving in the right direction,” he said on CNN. “We’re glad that the Senate is finally awake about this.”
The rare moment of bipartisan agreement on the intractable issue of gun control came after an elementary school shooting in Uvalde, Texas, which killed 19 students and two teachers, and a racist attack in Buffalo, where a gunman killed 10 Black people in a supermarket, pushed the issue of gun violence to the forefront in Washington, where years’ worth of efforts to enact gun restrictions in the wake of mass shootings have failed amid Republican opposition.
Discussions were helmed by Senators Christopher S. Murphy, Democrat of Connecticut and a longtime champion of gun reform legislation, and John Cornyn, Republican of Texas and a trusted ally of G.O.P. leadership. For days, roughly a dozen senators — including veterans of failed attempts to reach similar deals — huddled on Zoom, over the phone and in basement offices on Capitol Hill to reach an agreement before the Senate leaves for a scheduled Fourth of July recess.
Luke Broadwater contributed reporting.