In exchange, the district will restore the full-time hours of nearly 200 drivers.
The district had slashed their work day to seven hours due to the budget shortfall.
The union says the decision is a major sacrifice but worth it to preserve jobs.
District Superintendent Ramon Cortines is urging other unions to make similar offers.
Under the agreement between the district and the Service Employees International Union Local 99, more than 1,000 full and part-time bus drivers will take the furlough days during the current school year.
LAUSD bus drivers transport about 55,000 students each day.