The College Board is eliminating SAT subject tests, as the pandemic accelerates a push for changes in college admissions.

The 20 subject tests have been offered for decades in areas including math, English literature, world history and physics, but have fallen out of favor as a requirement for college applications. Between 2016 and 2019, registrations for the test fell by 8%—and dropped sharply last year, as test sites were closed due to the coronavirus pandemic.

The College Board said Tuesday that Advanced Placement courses are more suitable measures of a student’s knowledge in specific subject areas these days, as they “provide the type of hands-on learning experiences and practical, real-world work that colleges want to see from students.”

The nonprofit group said the AP’s ‘“widespread availability for low-income students and students of color means the Subject Tests are no longer necessary for students to show what they know.”

The decision doesn’t affect the main SAT.

There has been a broad shift away from standardized tests in admissions in recent years. Schools are also reconsidering the value of the main SAT, citing concerns that test scores are often closely tied to a student’s race and wealth and hurt the admissions odds of low-income students and communities of color.

About half of four-year colleges and universities made the test optional for admissions this year after the pandemic closed test sites around the country. Some said they would return to requiring the tests once public health concerns wane.

U.S. students will automatically have their subject test registrations canceled and receive a refund. International students will still be able to take the tests in May and June.

Some specific academic programs at individual colleges had still required SAT subject tests for admission, though students applying for general admission mainly had the option of whether to submit scores.

At Union College in Schenectady, N.Y., the Leadership in Medicine Program requires both a math and a science SAT subject test. Students who are admitted to the program and graduate from Union are automatically admitted to the Albany Medical College, said Matt Malatesta, vice president of admissions at Union.

“The SAT subject tests generally confirm what we already know from other parts of the application,” he said.

Mr. Malatesta added that Union has already been test-optional for the SAT for about 15 years.

The College Board is also discontinuing the optional essay portion of the SAT beginning after the June 2021 test administration date. The essays, first introduced in 2005 and then made optional beginning with 2016 tests, faced criticism from admissions officers and educators in their initial iteration. Colleges continued to favor application essays over the SAT writing sample in their admissions reviews.

Robyn Lady, director of student services at Chantilly High School in Virginia, applauded the latest move. She said many students took subject tests earlier in high school, while enrolled in biology or world history and before they knew for sure where they’d apply to college. Those who could afford it hired tutors, while others sweated over test registration fees. They didn’t realize how unnecessary that all was, Ms. Lady said.

“Anything that moves us closer to simplifying the process for students and removing barriers is a move in the right direction,” she said, adding that she’d like to see all standardized tests eliminated from college admissions. “This is all about equity and access.”