BIRMINGHAM, Ala. (AP) — Alabama’s reigning Teacher of the Year says she has resigned after state officials told her she’s unqualified to teach in her fifth-grade classroom because of certification issues.

Veteran teacher Ann Marie Corgill said Alabama Department of Education officials recently informed her that she was not qualified despite her well-documented accomplishments. She said she grew tired of trying to prove herself, prompting her to submit a letter of resignation, dated Tuesday and obtained by Al.com. In the letter, Corgill cites her confusion.

“After 21 years of teaching in grades 1-6, I have no answers as to why this is a problem now, so instead of paying more fees, taking more tests and proving once again that I am qualified to teach, I am resigning,” Corgill wrote.

Corgill has Class A and B certifications to teach primary school through third grade, according to certification records provided by The Alabama Department of Education. Corgill said she started this school year at Birmingham’s Oliver Elementary School teaching second grade, but shortly after the semester began, she was moved to a fifth-grade classroom.

In a news release Thursday, the state Department of Education said it “did not determine Ms. Corgill was not qualified. However, when an inquiry was made, the department reported that her current teaching certificate covers primary grades through Grade 3. This does not carry with it a requirement for resignation.”

But Corgill — a 2015 National Teacher of the Year finalist — holds National Board Certification to teach children ages 7 to 12, a group that would include most fifth-graders. That certification is valid until November 2020, according to the National Board Certification directory.

Birmingham City Schools spokeswoman Chandra Temple said Thursday that the district is working on the matter and had no further comment.

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