DENVER - In debates over education reform, D.C. public schools and other troubled urban systems tend to dominate the scene. But a national conference hosted here by the Obama administration gave a rare platform for suburban schools from the Washington area and beyond to show off their projects or join the quest for innovation.

Among those shopping for ideas last week were teachers union and school leaders from Anne Arundel County, a Maryland suburb not generally considered in the vanguard of reform. Yet the delegation was musing openly about the contentious idea of paying teachers, at least in part, based on performance instead of just credentials and seniority.

"It's absolutely worth talking about," said Timothy M. Menutti, president of the Anne Arundel teachers association. "You can't have anything off the table."

Superintendent Kevin M. Maxwell said some Anne Arundel schools "need a lot of work" even though Annapolis High School is a recent turnaround success story and the 75,000-student system is in good shape overall.

Maxwell said he is examining how teacher evaluations are evolving to include new metrics of student achievement. "I want to be part of the defining conversation," Maxwell said.

The two-day gathering in Denver, although pitched as a way to get labor and school officials to work together, made clear another point: A reform wave with roots in decaying urban systems is spreading to rural and suburban schools. Like those in the big cities, such systems face tough questions about struggling schools that fail to improve, layoff policies based on seniority and evaluations that often fail to hold weak teachers accountable.

About 150 school systems sent delegations to the labor-management conference, which was convened by the Education Department and ended Wednesday.

They ranged in size from 2,000 students (Lamoille North Supervisory Union in Vermont) to 400,000-plus (Chicago). Delegations were required to include labor, management and school board leaders. They also had to sign a pledge to work together on reform.

D.C. school and union officials were invited to give a clinic on lessons learned from the overhaul of their system but were unable to participate because of apparent disagreements about who would attend.

The contract D.C. teachers ratified in June after turbulent negotiations with Chancellor Michelle A. Rhee - who resigned months later - is widely known for provisions that enable high-performing teachers to receive large bonuses and give administrators more leverage in personnel decisions.

Instead, the conference promoted Montgomery County as a model from the Washington area. Superintendent Jerry D. Weast came with the county school board president and labor leaders to tout how the 142,000-student system works with unions to uphold professional and academic standards.

Montgomery officials said teachers are full partners in a peer review initiative that offers help to instructors who struggle and, in some cases, pushes low performers out of the system.

Montgomery's participation was notable because the county schools declined last year to join in Maryland's successful bid for a share of President Obama's $4 billion Race to the Top reform fund.

Some policies pushed by Race to the Top, especially formulas that incorporate test score data to rate teachers, were "not yet ready for prime time," Weast said.

Weast, who will retire this summer after 12 years in his post, said policies that alienate unions tend to backfire.

" 'Gotcha' just doesn't work too well," Weast said. "It causes teachers to hunker down, get fearful. It drives them toward unionization that is not positive."

Fairfax County Superintendent Jack D. Dale, who oversees a 174,000-student system, said he picked up some ideas here from Florida's Hillsborough County schools.

The Florida system, of similar size, is developing a way to pay teachers that relies on student achievement growth and peer evaluation instead of credentials and seniority.

Fairfax schools are not moving to jettison their seniority-based pay scale, Dale said. But he said the Florida example reinforced his own desire to pay teachers more for taking on larger professional roles as mentors, coaches and team leaders. Dale said he also would consider Montgomery's ideas on peer review for teachers.

"A true profession polices itself," Dale said. "And that's, I think, where it should go."

Prince George's County Superintendent William R. Hite Jr., also here, said he was impressed by a Baltimore schools contract that gives new weight to student achievement in teacher salaries. Hite said he and union leaders are reviewing results of a recent performance pay experiment in a portion of his 127,000-student system.

"It's brought us to the table to talk about effectiveness," Hite said.