About 11,000 California drivers have 30 days to retake the written knowledge test or lose their licenses after the state Department of Motor Vehicles said it identified "anomalies" in past exam results but declined to say what triggered the review.

The letters went out to drivers who took the written test between July 2025 and April 2026, the DMV confirmed.

Recipients must schedule an appointment, bring the DMV notice and pass a new exam within the 30-day window. Drivers who miss the deadline or fail the retake will have their licenses canceled.

The agency has not said what went wrong.

Officials declined to answer follow-up questions about whether the flagged results point to cheating, a data problem within the DMV or another issue.

"Ensuring the integrity of our testing process is essential," the department said in a statement.

"Knowledge tests play a critical role in confirming that drivers understand the rules of the road before they are licensed to drive in California."

The notices themselves carry sharper language.

Sacramento resident David Specht told CBS Sacramento he took the test in January after moving from Chicago and that his letter cited "non-compliance with the driver testing criteria required by state law."

Specht said he called the DMV for an explanation but received none. "I know I didn't cheat," he said. "And I presume many of the other 11,000 residents of California who received the letter also didn't cheat."

The rollout has landed unevenly across the state.

Drivers on Reddit reported receiving retest orders from field offices in San Francisco, Sacramento, Santa Monica and San Mateo.

San Francisco resident Sam Burgin told the Los Angeles Times he could not get an appointment at his local office and spent about $100 on a rideshare to San Mateo because he did not want to risk losing his license on the drive home.

The DMV has not tied the retest order to any specific detection tool. But the review comes days after Democrat Gov. Gavin Newsom announced a statewide partnership with Anthropic that makes the company's Claude AI assistant available to state agencies at a discount, with the DMV already using the tool for customer service.

The department has not said whether AI played any role in flagging the 11,000 tests, and it has not answered reporters' questions on the issue.

For affected drivers, the immediate stakes are practical: schedule the retest, pass it, or lose driving privileges. Walk-ins are not accepted.

The DMV has not said whether it will refund fees or offer accommodations for drivers who cannot reach a field office within the window.