What might be the name of the educational stages prior to the university?

What could one call the educational stages prior to university? I know that there are the primary, elementary and secondary levels of education. But is there a hypernym for just the aforementioned three types of education?

Solution 1:

I think you might find "compulsory education" works for you.

What it means depends on the region you're in but it literally means "required education" - or the years of education required by government.

Compulsory education refers to a period of education that is required of all persons and is imposed by law. Depending on the country, this education may take place at a registered school (schooling) or at home (homeschooling).

The one downside to this is the fact that it is dependent on your jurisdiction.

So, it varies by state in the US and each country may have a different concept of what years are required but, in general, it covers the years of schooling from elementary through high school.

Solution 2:

In the United States, Canada and Australia, primary and secondary education together are sometimes referred to as K-12 education, and in New Zealand Year 1–13 is used. The purpose of secondary education can be to give common knowledge, to prepare for higher education, or to train directly in a profession.

-Wikipedia Education

As @ab2 kindly affirmed K-12 is universally understood in the US.