Hundreds of D.C. students heading to school Monday morning were unable to use discounted Metro passes meant especially for them because of a “technical glitch,” transit officials said.

The issue affected more than 500 students using D.C. One cards, which include subsidized passes for traveling to and from school. As a result, some students had to pay a fare on top of what was spent on the pass to enter the system. Some students taking final exams were delayed.

Stefan Natzke of Capitol Hill said his daughter Emma, a junior at Wilson High, was turned away when she tried to enter the Eastern Market Metro station using her student card.

Emma was hurrying to get to Wilson to take her exams, but the station manager told her that “school was over with and therefore her card wouldn’t work,” according to her father.

“I was pretty angry,” said Natzke, who gave his daughter his SmarTrip card. She was late for her first final exam. She might not have gotten to school at all, Natzke said, if he had been at work and unavailable to help.

“It was certainly an inconvenience for us,” he said. “I’m sure it was worse for some other people.”

Metro spokeswoman Caroline Lukas said the problem was caused by a “a technical glitch” but said she didn’t know specifically what the problem was or why the passes were rejected.

Lukas said very few riders were affected before Metro “identified the problem and resolved it” by 9 a.m.

Students who were erroneously charged will receive an automatic credit, Lukas said. But she said she did not know how riders who had to use separate passes or cards to enter the system would receive refunds.

Metro has had problems in recent months dealing with fares, hours and timing. In March, Metro riders were charged peak fares for an additional hour the day after daylight saving time began. And Metro closed an hour earlier than normal the night clocks were turned back an hour in November, stranding riders. Fare gates at McPherson Square were malfunctioning for at least two days last month and would not read cards.

Monthly student passes can be purchased for $30 and allow for unlimited trips on buses or Metro trains during a calendar month. A monthly pass issued to a student for June is valid until June 30, according to Monica Hernandez, a spokeswoman for the District Department of Transportation.

The monthly passes for June were sold through last week. Monthly passes for the summer went on sale Sunday, five days before the last day for D.C. public schools.

Santos Lopez of Petworth said the issue affected his four children.

“My daughter said, ‘Daddy, we don’t have money on the card,’ ” Lopez said. “I told her that it had to have money. . . . We pay $30 for her monthly pass and it has to work.”

Sir Blair, 16, said he tried entering the Fort Totten station at 7:30 a.m. but his D.C. One Card didn’t work. When he asked the station manager, he was told to add money to his card.

“They already stole my money,” Blair said.

Nicole Chavez contributed to this report.