Some of Maryland’s largest school systems have joined a growing national movement to provide college admission testing to high school juniors at no charge.

But there’s a catch for many of these students and others around the country: The free exams won’t include the essay-writing portion that some highly selective universities require.

This month and next, most Montgomery County high schools will administer the SAT for the first time on selected school days, without the exam’s optional essay. Students who prefer the other major admissions test, the ACT, were offered vouchers to cover the $46 cost of registering to take it on a weekend without an essay.

The initiative, projected to cost up to $450,000 a year, aims to widen access to higher education. Many states and school systems in recent years have begun paying for admissions testing to help students prepare for college or perhaps think about it seriously for the first time.

“This really starts at removing barriers,” said Scott Murphy, director of secondary curriculum and districtwide programs for Montgomery County Public Schools.

Elsewhere in Maryland, schools in Anne Arundel County offer the ACT without the essay, and those in Frederick County offer the SAT without the essay.

But schools in Baltimore City and Baltimore County offer the SAT with the essay. So do those in the District of Columbia.

For students considering college, one possible barrier is money, although waivers for testing fees are available for those in financial need. Another is logistics: Some find it harder to get to a testing center on a weekend.

Variations in testing formats and admission rules also pose a challenge to students unfamiliar with the application maze.

The SAT centers on math and “evidence-based” reading and writing. Most questions in the three-hour exam are multiple choice, although students must write in answers to some math problems. The math and language sections produce two scores that add up to a maximum of 1600. The nonprofit College Board, which oversees the SAT, also added a 50-minute essay as an optional third part when it launched the redesigned test in 2016. The essay exam, which calls for analysis of a text, costs an additional $14 per student. It does not factor into the main score.

The ACT assesses students for nearly three hours through multiple-choice questions in English, reading, math and science, with a maximum score of 36. It also has an optional essay ($16.50 extra) that takes 40 minutes.

Some colleges don’t require any admissions testing, on the premise that what matters most is a student’s ability to get high grades in tough courses.

Most selective schools, including the flagship universities of Virginia and Maryland, require a test score but not an essay score. U-Va., one of the highest-ranked public universities, is emphatic: “The SAT Essay and ACT Writing sections are not required or used in our review,” it says.

A dwindling number of top schools do require SAT or ACT essay scores. These holdouts include the University of California, Yale, Duke, Princeton and Stanford universities.

That creates a dilemma for states and school systems that pay for admission testing: Should they also pay for the essay exams when most colleges do not require them? If they do not pay for them, are they hindering students who might want to apply to certain elite universities?

It also poses a challenge for those few universities: Are they losing out on otherwise deserving students because of their essay policy?

Nineteen states fund ACT testing in public schools. Of those, the ACT said, eight do not pay for the essay-writing option: Arkansas, Arizona, Kentucky, Louisiana, Mississippi, Ohio, Oklahoma and Tennessee. In all, 46 percent of students who take the ACT during the school day do not write an essay.

The College Board said 71 percent of students who took the SAT through the school day initiative in the past two years did so with the essay portion. The essay is standard for SAT programs in Delaware, Michigan, Illinois and several other states.

But this year, Idaho dumped essay testing from its SAT school-day program. It previously had been required, but districts found it more time-consuming than valuable, said Karlynn Laraway, assessment and accountability director for Idaho’s State Department of Education.

Connecticut also offers the SAT during school without the essay.

“Most Connecticut colleges don’t require it,” said Peter Yazbak, communications director for the state education department. “We did not want to lengthen the state assessment time if it was not absolutely necessary.”

One well-known Connecticut university that requires the essay is in New Haven.

Jeremiah Quinlan, dean of undergraduate admissions for Yale, declined to comment on the state’s testing policy. But he said he is closely monitoring results of the new SAT essay. “I’d really love to get four to five years of data,” he said, “to see how good essay scores are in predicting student success.”

Some prominent schools, including the University of Pennsylvania and Columbia University, have dropped essay-testing mandates in recent years. Harvard University’s admissions office said Thursday it will no longer require an essay score, starting with the class entering in 2019.

Nor do the Massachusetts Institute of Technology or University of Chicago require essay scores. James Nondorf, dean of admissions and financial aid at the University of Chicago, said he prefers to judge writing talent through the essays students send with their applications.

“The more I can empower students to showcase who they are, showcase their individuality and creativity, the better,” Nondorf said.

Colorado pays for SAT testing in high schools but lets students choose whether they want the essay portion. Last year, about 10,000 took the test with the essay, and 50,000 took it without.

In Montgomery County, where several high schools will give the test Wednesday, officials say the sheer size of the state’s largest school system means exam fees add up quickly. Montgomery has about 10,000 11th-graders. Losing valuable class time is also an issue. Murphy said adding the essay means the test would eat up most of a school day. Still, he said, the county is looking for ways in the future to help students get an essay score if they want one.

“We absolutely want to make sure students have the option to do the essay,” Murphy said. “We’re going to seriously consider the possibility of giving the essay during the school day.”

Correction: A previous version of this story quoted the ACT as saying that Utah does not fund the essay-writing portion of the ACT exam in its state testing program. ACT later said that Utah is starting to fund the optional essay-writing section this year. This version has been updated.