Montgomery County leaders announced an ambitious plan Thursday to increase access to child-care programs for low-income families, an effort to make children better prepared for kinder­garten in some of the poorest pockets of the Maryland suburb.

The initiative, aimed at children from birth to age 5, is slated to bring 600 additional seats to programs in family homes, centers and school classrooms during the next year as the first step in a four-year plan.

County officials said the idea is to improve opportunities for the 30,000 economically vulnerable children in Montgomery who are under age 6. That, officials hope, will improve the trajectory of the children’s learning as they progress through school.

“We know the first five years of life are critical to brain development for children, and this sets the foundation for all future learning,” County Executive Marc Elrich (D) told the audience that packed a room in county offices in Rockville.

Elrich recalled his years as a teacher in a high-needs Montgomery County school and said that schools are pressured to succeed but that problems begin much earlier.

“We know that only 54 percent of our children are ready to enter kindergarten — and that has real serious implications for how things go,” Elrich said.

Officials said the first year of the initiative will be largely funded through existing resources within the health and human services department, with $7 million proposed for future efforts in an operating budget proposal that Elrich is expected to offer next week. The school system’s budget proposal includes $1 million slated for a prekindergarten program for 85 to 95 students to open in the fall in the upper end of the county.

Nancy Navarro, president of the Montgomery County Council and a longtime advocate on the issue, called the initiative an idea long in the making. Only one of four children from low-income households in Montgomery enter school ready to learn, she said.

She invoked her years as a parent, when she struggled to find high-quality, affordable care. She eventually quit her job and became a home-based child-care provider for four years.

“Truly, it is a moral and an economic imperative,” Navarro (D-District 4) said, adding that gaps in opportunity at younger ages become achievement gaps during school years and affect students who need to prepare for the changing world of work.

“We must be strategic and invest in the early years,” she said. “It is the best return on investment and prepares all of our children to succeed. It is the great equalizer.”

The effort is expected to bring together officials from county agencies, the school system and Montgomery College, and involve public-private partnerships over time.

In the first year of the initiative, officials will recruit 50 family child-care providers — who run small operations in their homes — and provide business support and coaching as they seek licensing. High-need areas targeted include Gaithersburg, Montgomery Village, Glenmont-Wheaton, Burtonsville, White Oak and Silver Spring.

Some money will also go toward serving children who reach the age when they’re no longer eligible for Early Head Start programs.

The prekindergarten expansion that school officials have planned will resemble a similar program, the MacDonald Knolls Early Childhood Center, that recently opened in Silver Spring and includes special education students.

As the county seeks to expand child-care options later, officials will look to potentially locate in a variety of settings: commercial spaces, public facilities, faith-based centers and other places. The initiative will be guided by recommendations from a working group.

County Schools Superintendent Jack R. Smith echoed the importance of the effort, thanking county leaders and calling it “a giant step forward” that should be a “fully integrated community program.” The school system “cannot and should not do this work alone and in isolation,” he said.

Montgomery College will play a role in offering training and degrees in early-childhood education, including an online degree, the school’s president, DeRionne Pollard, said. The college expects to provide professional development for existing child-care providers and facilitate certifications for aspiring operators.

“Graduating more residents with the skills to serve young children is our goal,” Pollard said.

County officials said they will monitor possible state action on early childhood recommendations from the Kirwan Commission, which has been charged with reshaping the state’s public school system.

Community leaders pointed to a great need for the program.

Diego Uriburu, a longtime leader in the Latino community in Montgomery, said many families cannot find quality child-care programs in their neighborhoods — and don’t have the means to drive across the county looking for slots.

“It’s great news to hear that there’s a plan, first, and that there’s money, second,” Uriburu said. “There are lots of families with no options, and they struggle mightily.”

CORRECTION: An earlier version of this story misstated the funding arrangement. The first phase of the initiative will largely be supported by existing resources, while a proposed $7 million budget allocation would go toward future efforts.