Massachusetts has collected about $1.8 billion from a voter-approved surtax on the state’s highest earners through the first nine months of the fiscal year, the Department of Revenue said Monday in a quarterly report.

That’s more than $800 million more than what the Legislature and Gov. Maura Healey planned to spend in surtax revenue for all of fiscal year 2024, raising the possibility of a sizable pot that will land in an Education and Transportation Reserve Fund and the Education and Transportation Innovation and Capital Fund, both surtax-specific accounts, once the books close.