(The Center Square) – Most school districts in Colorado will begin raising property tax mill levies in December, the Colorado Department of Education (CDE) said on Monday.

The move is mandated by House Bill 21-1164, which Colorado Governor Jared Polis signed into law in June. The bill removes property tax mill levies from consideration under Colorado’s Taxpayer’s Bill of Rights (TABOR), which limits how much money the state can accrue in revenue each year.

The bill is expected to bring in approximately $80 million per year, according to its fiscal note.

Between the 1990s and 2000s, CDE says voters in several school districts approved plans to allow their schools to retain funds above the TABOR limit – a move known as "de-TABORing." The property tax mill levy rates in the districts that passed de-TABORing were also capped in place at the time of the vote.

CDE said it interpreted the state statute to require school districts to reduce their property tax mill levies to 2007 levels, an interpretation that CDE now says was erroneous.

Last year, impacted school districts began implementing tax credits to backfill the difference between their current mill levy rates and their 2007 levels, a move that CDE said should not have happened.

“Subsequent legal interpretation now makes it clear that local property tax collections should not have been reduced,” CDE said in a statement.

To rectify the tax bills, taxpayers will see a maximum one mill increase to their property tax bills this year and each subsequent year until the tax credits are zeroed out, CDE said. The department posted districts' changes, which can be viewed here.

This mill levy correction will “free up state funds” for at-risk and English as a Second Language learners, CDE added.