Maryland lawmakers are poised to pass legislation that will eventually boost annual state education spending in Prince George’s County by more than $13 million a year.

The state Senate on Wednesday advanced the measure, a priority of County Executive Rushern L. Baker III (D), which passed unanimously in the House of Delegates last month. A final Senate vote is expected before the legislature adjourns on Monday.

The bill alters a state education formula based on wealth in the state’s 23 counties and Baltimore.

Under the change, a snapshot of wealth based on tax returns would be taken twice: once in September, as is now the case, and again in November. School systems would receive the greater amount of state funding that results from the two calculations.

Prince George’s officials have long argued that the current formula benefits counties, such as Montgomery, where more people seek extensions and file their taxes later in the year.

The bill, sponsored Gov. Martin O’Malley (D), assures that Montgomery would not lose any money under the new calculation. The additional funding to counties including Prince George’s would be phased in over five years.

Legislative analysts project the bill will cost the state about $56 million once it is fully phased in.

A similar change was included in an early version of a gambling expansion bill considered by lawmakers last year. The provision was dropped from the bill after O’Malley agreed to pursue separate legislation this year.

Separately this year, Baker is seeking passage of legislation to give him greater control over governance of the Prince George’s schools.