A NEW report shows that Montgomery County Public Schools has lost ground in recent years in narrowing the achievement gap between its high-poverty and low-poverty high schools. The depiction of a system geographically divided between highly ranked schools serving affluent, mainly white and Asian students and those where poor and mainly minority students struggle should serve as a wake-up call for renewed action.

“Since 2010, the economic, racial and ethnic stratification of students among MCPS high schools has increased . . . the achievement gap between high- and low-poverty high schools has widened . . . MCPS’ approach is not working as intended.” Those were the discouraging findings of the County Council’s Office of Legislative Oversight. Its report, comparing 11 high-poverty high schools in the county’s Northeast and Downcounty Consortium with 14 low-poverty high schools in western and other parts of Montgomery, had some positive notes: improved graduation rates and decreased suspension rates. It’s also important that even as the gap persisted between groups, generally there was across-the-board improvement in performance.

Nonetheless, the entrenchment of a two-tier system of have and have-not schools is troubling. Without a doubt, some demographic forces are beyond the control of school officials, and some demographic changes occurred faster than expected. And the achievement gap is neither new nor unique to Montgomery. But given the promising progress made in previous years in attacking the gap, particularly under the sustained focus of former superintendent Jerry Weast, the stagnation now is alarming.

Joshua P. Starr, who took over as superintendent from Mr. Weast in 2011, seems to have directed his efforts elsewhere — deemphasizing standardized tests, for example, and urging more “hopefulness” and innovation in education. He acknowledged to us that the system’s efforts in attacking the achievement gap have been akin to “treading water” in recent years, but he said that is not for lack of commitment or interest. Instead, he faulted a lack of resources and noted that his 2015 budget proposal calls for additional funds to benefit vulnerable students, including reducing class sizes in high-need high schools, improving services to English-language learners and hiring more counselors and student support staff.

It will be instructive to see what happens to those planned programs if school officials get less money than requested in what has come to be an annual battle with the council. We have argued that the problem with Montgomery school funding is not the amount (more than half of the county budget) but how it’s spent. One wonders, for example, if the outcome of this report would have been different if some of the money used for across-the-board pay raises had gone into more support for students most in need or for middle-school improvement. Committed leadership is as important as resources. We hope Mr. Starr will recommit the system to this cause.