The graduation rate for the District’s traditional public high schools dropped 3.5 percentage points in 2019 — the second consecutive decline since the system faced scrutiny over whether students properly earn their diplomas.

The rate for high schools in the traditional system slid to 65.1 percent. In 2017, the school system posted a record high rate of 73 percent — a rate later cast into doubt amid a graduation scandal that jolted the city.

The Office of the State Superintendent of Education released the graduation data Friday for the traditional public and charter school sectors. Overall — accounting for both sectors — the 2019 graduation rate was 68.2 percent, essentially unchanged from 2018.

Charter schools, which educate far fewer high school seniors than the traditional system, graduated 76.4 percent of their seniors, a four percentage point increase from 2018. In all, the city graduated 3,359 students last spring who started high school four years earlier.

“These results show we clearly have more work to do in ensuring all students graduate from high school on time, prepared for success in college and the career of their choice,” D.C. Mayor Muriel E. Bowser (D) said in a statement.

Graduation rates in the traditional public school system have tumbled since a citywide investigation found that 1 in 3 graduates in 2017 received their diplomas despite missing too many classes or improperly taking makeup classes.

D.C. Schools Chancellor Lewis D. Ferebee said the school system has continued to tighten graduation requirements, and he said he is confident that students in the Class of 2019 who walked across the graduation stage earned their diplomas.

Ferebee attributed some of the decline in the graduation rate to changes in the credit recovery program, which came under fire in the wake of the citywide investigation. That program allows students who have failed a class to recover credits in courses outside of traditional school hours.

The school system has made the standards for credit recovery courses more consistent across the city and now requires students to pass exams to show that they have learned the material.

Ferebee said students were unable to enroll in credit recovery courses for one academic quarter last year as the school system revamped the program. As a result, he said, there was a slight decline in the number of students who earned credits through the recovery program last year.

The chancellor said revamped graduation procedures and programs that the city has implemented will take time to yield changes, and he believes the graduation rate may go up next year.

“We always want to see more of our students graduate,” Ferebee said in an interview. “But we also want them to be prepared for the next step.”

Sixteen out of the nearly 40 traditional and public charter high schools in the District experienced a graduation rate increase. A few schools saw double-digit gains or losses.

Ferebee said he does not read much into big year-to-year changes in a school’s graduation rate. Changes in one graduating class compared with another — perhaps one class has significantly more special education students — could explain the fluctuation, he said.

The graduation rate for Coolidge Senior High School jumped from 56 percent to 66 percent. The rate for H.D. Woodson dropped from 76 percent to 66 percent. Dunbar, where the graduation rate increased 10 percentage points to 86 percent in 2018, decreased to 76 percent in 2019. Ballou High — the school that sparked the investigation of graduation rates — recorded an increase to 58 percent from 55 percent.

The school system’s four opportunity academies, which are alternative high schools, all had low graduation rates, which city officials said was expected.

In the charter sector, IDEA Public Charter School — which had a 55 percent graduation rate in 2018, one of the lowest in the city — reported a 25 percentage point gain in 2019. Somerset Preparatory, which changed charter operators this academic year because of low performance, experienced a sharp drop to 65.7 percent.

“Increasing graduation rates are an important part of the story, but we also need to make sure our graduates are prepared for college and the workforce,” said Scott Pearson, executive director of the D.C. Public Charter School Board.

Citywide, Hispanic students, students from low-income families and students with disabilities experienced declines in graduation rates.

Graduation rates were determined by calculating the percentage of students who entered a high school in 2015 and graduated four years later in 2019. If a school has paperwork documenting that a student transferred schools, then that teen is not factored into a campus’s graduation rate.

While the graduation rate in the traditional public school system declined, Ferebee pointed to other measures he says indicate students are better prepared for college. Participation and passage rates on Advanced Placement exams increased last academic year. SAT scores also increased.

Fifty-five percent of 2018 high school graduates enrolled in college last fall, a seven percentage point increase from 2017.