Ooltewah High School principal Mark Bean talks to a student during lunch break at the school in Ooltewah, Tenn.

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Ooltewah High School students now can take a globally recognized curriculum right at home with the school's approval for an International Baccalaureate diploma program.

Ooltewah is the 13th high school in Tennessee to earn IB designation. Recognized by schools and colleges around the globe, the IB curriculum is considered more challenging than regular coursework. It's even believed to be tougher than the Advanced Placement courses common in many high schools.

"This is the most rigorous curriculum there is," said Principal Mark Bean.

With their IB diploma program, Ooltewah students join a network of 3,570 schools in 145 countries with some sort of IB program. Locally, Signal Mountain Middle/High holds both the diploma program for juniors and seniors and a middle years program for students in grades six through 10. Brown International Academy offers the primary years version of the IB program.

To receive the IB diploma, students must complete prerequisites and six approved courses, a 4,000-word essay and pass exams that are judged by instructors from all over the world.

Ooltewah students will start preparing for IB in their freshman and sophomore years, and complete the IB classes their last two years. So far, 326 students are participating.

It costs more than $10,000 annually to maintain a school's IB status, officials said, plus more for supplies and expensive teacher training. Altogether, Ooltewah High has spent about $75,000 annually over the last three years, said Karla Riddle, who oversees the county's IB programs. That figure is expected to shrink going forward as most teachers already are trained in IB.

"We have made a big investment in our kids and our schools," she told Hamilton County Board of Education members last week. "But I think in the long run it's going to pay off."

The IB program will allow international students to easily transfer credit from Ooltewah to other countries. That's especially important for European companies like Volkswagen and Wacker that often dispatch families here for only a few years at a time. Riddle says many European schools won't recognize coursework students complete in the United States because U.S. standards are lower.

Beverly Hollingsworth, Ooltewah's IB coordinator, said the school currently has more than 200 international students from 22 countries. But IB will better position all students, not just those from overseas.

Those who complete the program may get into more selective colleges. And they'll receive up to 30 hours of college credit at only the cost of taking an exam.

"They're getting college credit at a high school level for free," Hollingsworth said.