The Labor Department announced the fines Thursday.
The department says the violations included allowing workers under 18 to perform hazardous jobs that are prohibited. That included loading or operating power-driven paper balers, meat slicers, bakery machines and motor vehicles. No underage workers were injured.
The Labor Department report says Hy-Vee was assessed $68,200 for 27 violations at seven stores, while Fareway was assessed nearly $20,000 for 13 violations at eight stores. The violations would have happened since October 2011.
Representatives of Hy-Vee and Fareway say the stores are committed to maintaining a safe environment for young workers.