Filed pursuant to Rule 497(e)

Registration No. 333-07305

FRONTIER FUNDS, INC. (the “Corporation”)

Frontier Phocas Small Cap Value Fund (the “Fund”)

Institutional Class Shares (FPSVX)

Service Class Shares (FPVSX)

Supplement dated June 2, 2017, to the Prospectus dated October 31, 2016

Pursuant to a new expense limitation agreement approved by the Board of Directors of the Corporation, Frontegra Asset Management, Inc., the investment adviser to the Fund, has agreed to waive its management fee and/or reimburse the Fund’s operating expenses to the extent necessary to ensure that the Fund’s total operating expenses (excluding taxes, interest, brokerage commissions, acquired fund fees and expenses and extraordinary expenses) do not exceed 0.95% and 1.10% of the Fund’s average daily net assets attributable to Institutional Class and Service Class shares, respectively, effective July 1, 2017, through October 31, 2019.   

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