Standardized tests — including the SAT college admissions exam and annual K-12 exams federally mandated in states throughout the country ― are being postponed or canceled because of the coronavirus pandemic.

The SAT exam scheduled to be administered worldwide Saturday has been canceled in more than 15 countries, and a growing number of U.S. schools that host it are backing out.

The Saturday administration of the SAT was canceled by the College Board, which owns the exam, in some 20 countries, including China, Japan, South Korea, Saudi Arabia, Greece and Italy. A shortage of proctors led to cancellations at dozens of U.S. schools set to administer the exam. (You can see the list here.)

The next ACT college admissions test is scheduled for April 4, with Friday being the last day to register, according to ACT’s website. Whether events will lead the ACT to cancel or reschedule that test remains to be seen.

Many mandated standardized tests in K-12 schools are given in the spring, and the spread of the virus will wreak havoc with some testing schedules. The results are used for different reasons, depending on the exam, but there are consequences for schools, students and teachers for most of the exams.

Education Secretary Betsy DeVos issued guidance Thursday on how schools should handle the crisis and said it is possible her agency would grant waivers from federally mandated testing requirements.

“In cases where a school has been closed for a period of time, the assessment results still provide useful information about where individual students and groups of students will need support in the following school year,” the guidance says.

“However, due to the unique circumstances that may arise as a result of COVID-19, such as a school closing during the entire testing window, it may not be feasible for a state to administer some or all of its assessments, in which case the department would consider a targeted one-year waiver of the assessment requirements for those schools impacted by the extraordinary circumstances.”

Ohio Gov. Mike DeWine (R) announced a three-week closure of all public, charter and private schools starting Monday, which comes in the middle of mandated standardized testing in that state. DeWine said the tests would obviously have to be delayed — or even canceled.

“If we can’t have testing this year, we will not have testing this year,” he said at his daily briefing on the coronavirus. “The world will not come to an end.”

Seattle Public Schools closed Thursday for at least two weeks, right in the middle of the district’s spring standardized testing season. Tim Robinson, spokesman for the Seattle school district, said testing began March 2 but that it is still unclear how the district will proceed because of the disruption.

“This is all in progress now [and we’re] trying to figure it out,” he said.

Maryland Gov. Larry Hogan (R) announced that Maryland schools would close from March 16 through March 27, and officials in Michigan and New Mexico also announced statewide school closures for three weeks. Kentucky Gov. Andy Beshear (D) encouraged schools across his state to close for a few weeks but did not mandate it. Some standardized tests are scheduled during those periods, but it is not clear what the states will do.

More than 100 California public schools have closed, but the state’s guidance on how schools should handle the virus do not mention standardized testing.

EdSource reported that one Northern California system, Palo Alto Unified School District, had announced plans to cancel standardized tests scheduled for March and April in math, science and English/language arts, but state officials said they couldn’t. Now, the district will administer the tests in late April or May, if schools are open.

“In their rush to protect students and staff by shutting down schools, education policymakers have not had time to think through the implications. In Washington State and elsewhere, state-mandated standardized exams are scheduled to begin in the late winter or early spring,” said Bob Schaeffer, interim executive director of the nonprofit National Center for Fair and Open Testing.

“What happens if a school is closed during the entire testing period? Or if a building happens to reopen after classes were suspended (or ‘online’) for several weeks, how will score reports account for the absence of teaching time or the huge psychological disruption for many kids?” Schaeffer said. “This should be a particular concern for tests with major educational consequences for students, educators or schools, such as grade promotion or high school graduation exams.”