A veteran Teacher of the Year in Alabama has resigned after 21 years in the classroom after local authorities told her she is unqualified to educate fifth graders.

Ann Marie Corgill was told by the Alabama Department of Education that her qualifications were not up to scratch, despite being 2015 National Teacher of the Year and 2014-2015 Alabama Teacher of the Year finalist. She is also the author of teaching book called “Of Primary Importance”.

Ms Corgill said she was tired of having to prove herself and did not want to pay more fees, and sent Birmingham City Schools a letter of resignation.

In the letter, first obtained by Al.com, she wrote: “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.”

Ann Marie Corgill appears in an author photo. Ann Marie Corgill/Stenhouse Publishers (Ann Marie Corgill/Stenhouse Publishers)

The Alabama Department of Education records show Ms Corgill, who says on her Twitter profile that she is living her “God given purpose as a classroom teacher and learner”, has Class A and B certifications to teach primary schoolers through the third grade. The teacher was moved to teach a fifth grade class after the semester started at Oliver Elementary School, Birmingham. However, Corgill holds the National Board Certification to teach children aged 7 to 12, which would include most children in with grade, and it is valid until 2020, according to the National Board Certification directory.

Corgill has taught for over two decades in Alabama and in New York, and spent two years as a national consultant for the Developmental Studies Center.

Alice King, the New York-based education consultant at the Center for the Collaborative Classroom, told The Independent it was “crazy” that Corgill has resigned.

“She is brilliant and it’s interesting they [the State authorities] would feel that way about a published author. We loved working with her, the teachers always got something out of what she had to offer.”