Akins High School sophomore Marisol Castro Soto said she had fallen in with the wrong crowd.

She and her friends would frequently skip school or show up to classes at their leisure. But when the 16-year-old was threatened with going before a judge because of her absences, Marisol knew it was time for a change.

She volunteered for the Austin school district’s new truancy program, which uses GPS trackers to help prompt students to go to class more often. Students who miss more than 10 days of school lose credit for their courses, officials said. At that point, students and parents may be summoned to court for truancy and may face misdemeanor charges and fines and be found criminally negligent.

Unlike the controversial Radio Frequency Identification System, or RFID, tags the Northside school district made mandatory at two San Antonio area campuses, the Austin program requires student and parental written consent.

The Austin district implemented the program this school year at nine high schools, targeting the campuses with a high number of students who are chronically absent, district administrators said. Students at Akins, Crockett, Eastside Memorial, International, Lanier, LBJ, McCallum, Travis and Reagan high schools participate. Austin, Bowie and Anderson high schools are the only traditional campuses not on that list.

The district tested the program with 75 students at Eastside Memorial last year.

“It’s very helpful,” Marisol said. “At the beginning of the school year, I messed up a lot, and I skipped. I decided to take the second chance they were giving me and be in the program. Ever since I’ve been in that program, it made me focus more on my classes.”

More than half of all Central Texas students miss six or more days of school, accounting for 85 percent of all absences, according to 2010-11 data by E3 Alliance. Findings by the education advocacy group, which collected data from 35 area districts and 15 charter schools, show that students from low-income families miss the most school, with an average of 15 absences.

“If our students don’t attend, they can’t get the instruction they need from their classes,” said Crystal Bernard, the district’s administrator supervisor for high school programs. “It’s marrying the technology that our students are already comfortable with, to get them excited about coming to and attending school.”

Tamping down on cutting classes has an added bonus in a state that funds districts based on attendance: Increasing student attendance by 2 percentage points, or an average of three days per year, would add $34 million to Central Texas school coffers, according to the findings by E3 Alliance.

Austin’s program is run by Dallas-based AIM Truancy Solutions. AIM’s GPS tracker is smaller than most phones. Students must check in several times a day, including when they leave their houses in the mornings, when they arrive at school, after lunch and when they leave school for the day. Marisol and the other 500 participating students also must sign attendance sheets with teachers to validate their presence. The program gives students options for wake-up calls and mentoring.

The company audits attendance records with GPS check-ins and can detect if a student tries to hand off a tracker to a friend.

The Austin school district pays AIM based on performance: $47 for each additional average daily attendance day a student is in class, with a total annual amount not to exceed $1 million.

The district’s goal is to outfit 500 more students with the trackers.

Early figures show that before enrolling in the program, students were attending school on average about 78 percent of the time. Those same students are averaging a 90 percent attendance rate since they began participating.