Maryland's elementary and middle schools improved reading and mathematics test scores for a second straight year, with black and Hispanic students closing achievement gaps in some key measures, according to state data made public yesterday.

Results from the 2005 Maryland School Assessments were seen as encouraging for one of the Washington area's lowest-ranked school systems. Prince George's County built on the previous year's solid gains, with scores rising for nearly every group of students.

But statewide results showed far more progress in the earlier grades than in the later grades, raising the urgency of efforts to overhaul middle schools after years in which educators have focused on the elementary level.

More than three-quarters of students in grades 3 and 4, for example, scored at a proficient or advanced level in reading and math. But barely half of the state's eighth-graders, just 52 percent, did that well in math.

"Now we have to really focus on reform in middle school," said Frieda Lacey, a Montgomery County deputy superintendent.

The results also showed some school systems beginning to close what might be called a geographic achievement gap.

In Prince George's, 63 percent of third-graders reached proficiency or better in reading, lower than the statewide level of 76 percent. But it represented an enormous 24-point jump from the county's proficiency rating two years ago and a faster rate of increase than the state average.

In Montgomery and Howard counties, with affluent and highly ranked suburban school systems, the challenge was to push high scores even higher. In Montgomery, 79 percent of third-graders reached proficiency or better in reading, and in Howard, 88 percent did. More than 20 percent of Montgomery's third-graders and more than 30 percent of Howard's scored at an advanced level in reading.

"We are encouraged by this progress," state School Superintendent Nancy S. Grasmick said in a telephone interview.

Grasmick ascribed the higher test scores to a voluntary statewide curriculum that has helped students adjust when they move from one county to another. She also said teachers and principals are growing accustomed to the state assessments, which have now been administered three times.

The Maryland tests, given in March, are the most significant factor in determining whether the state's 24 school systems and roughly 1,050 elementary and middle schools are meeting increasingly tough annual performance standards established under the No Child Left Behind law President Bush signed in 2002.

The federal ratings for Maryland elementary and middle schools are expected to be released next week. Officials caution that these ratings, using a benchmark known in education circles as "adequate yearly progress," may trip up many schools even if their scores have improved. Ratings for Maryland high schools and schools in Virginia and the District are due in the summer.

Schools that fail to make adequate progress can be put on watch lists and, if they lag repeatedly, must offer students extra tutoring and a chance to enroll in a better public school. Schools can face further state sanctions if test scores don't improve.

State officials said all 24 school systems showed gains, with certain groups of black and Hispanic students making faster progress as they seek to catch up to their white and Asian American peers.

For example, 64 percent of African American third-graders scored at proficient or better in math, up from 47 percent in 2003. In third-grade reading, 63 percent of Hispanic students reached or exceeded proficiency, up from 39 percent in 2003.

"That's pretty stunning," Grasmick said.

What's more, scores showed that some historic achievement gaps are narrowing. In 2003, 79 percent of non-Hispanic white third-graders scored at proficient or better in math; this year, 87 percent did.

Black students are now 23 percentage points behind non-Hispanic white students, after being 32 points behind two years ago.

A comparable narrowing occurred with Hispanic third-graders in reading, as the gap with non-Hispanic white students shrank to 22 percentage points from 33 points.

In third, fifth and eighth grades -- the only ones with data available from 2003 through 2005 -- there was no instance in which blacks and Hispanics statewide fell appreciably further behind non-Hispanic white students in reading or math. However, the data showed that racial and ethnic achievement gaps appeared to be widest and most unyielding in the eighth grade.

State officials also reported that low-income students and disabled students who qualify for special education had achieved higher test scores.

Across Maryland, school systems touted improved test scores after days of analyzing the numbers privately. The public got to see the scores for the first time about noon yesterday on a state Web site, www.mdreportcard.org.

In Anne Arundel County, the percentage of third-, fifth- and eighth-graders achieving advanced levels in math more than doubled in two years. And more students were reaching proficiency.

"There are 2,000 more students who are proficient in math this year than there were last year. Those are real kids," said Jonathan Brice, who oversees the Anne Arundel school assessment.

In Charles, Calvert and St. Mary's counties, schools reported broad gains. "I think the key is data-driven decision-making in the classroom, constantly analyzing where the child is in the learning process . . . and having fidelity to the curriculum," said Lorraine Fulton, interim superintendent in St. Mary's.

In Montgomery, four out of five elementary school children scored at least proficient in reading and math, with fourth-graders making the greatest strides while sixth-graders slipped a bit in reading. In Howard, at least 80 percent of test-takers scored proficient or better in reading in every grade, and at least 60 percent did so in math, with scores rising by double digits for some grades.

Howard Superintendent Sydney L. Cousin called the results "nothing short of remarkable."

Staff writers Daniel de Vise, V. Dion Haynes, Rosalind S. Helderman, Ann E. Marimow, Ylan Q. Mui, Joshua Partlow and Nancy Trejos contributed to this report.