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Frontier MFG Global Plus Fund

Frontier MFG Global Plus Fund

FRONTIER FUNDS, INC.

Frontier MFG Global Plus Fund

Institutional Class Shares (FMGPX)

Service Class Shares (FMPSX)

Class Y Shares (FMGYX)

Supplement dated December 23, 2019, to the Prospectus dated October 31, 2019

The table and related disclosure under “Summary Section — Fees and Expenses of the Fund” is hereby deleted and replaced with the following:

Fees and Expenses of the Fund.

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees - Frontier MFG Global Plus Fund - USD ($)	Institutional Class	Service Class	Class Y
Redemption Fee (as a percentage of Amount Redeemed)	2.00%	2.00%	2.00%
Redemption Fee	$ 15.00	$ 15	$ 15

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses - Frontier MFG Global Plus Fund		Institutional Class	Service Class	Class Y
Management Fees (as a percentage of Assets)		0.80%	0.80%	0.80%
Distribution and Service (12b-1) Fees		none	none	0.25%
Component1 Other Expenses		none	0.15%	0.15%
Component2 Other Expenses	[1]	0.09%	0.09%	0.09%
Other Expenses (as a percentage of Assets):		0.09%	0.24%	0.24%
Acquired Fund Fees and Expenses	[2]	0.03%	0.03%	0.03%
Expenses (as a percentage of Assets)	[3]	0.92%	1.07%	1.32%
Fee Waiver or Reimbursement	[4]	(0.09%)	(0.09%)	(0.09%)
Net Expenses (as a percentage of Assets)	[2]	0.83%	0.98%	1.23%

PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE

[1] Class Y shares had not commenced operations as of June 30, 2019. Accordingly, “Additional Other Expenses” for the Class Y shares are estimated based on other expenses of the Institutional Class shares of the Fund for the fiscal year ended June 30, 2019.

[2] Acquired Fund Fees and Expenses (“AFFE”) are fees and expenses incurred by the Fund in connection with its investments in other investment companies. Total Annual Fund Operating Expenses shown will not correlate to the Fund’s ratio of expenses to average net assets appearing in the Financial Highlights table, which does not include AFFE.

[3] The “Total Annual Fund Operating Expenses” and “Total Annual Fund Operating Expenses After Fee Waiver” for Service Class shares do not correlate to the “Ratio of expenses to average net assets” figures in the Financial Highlights section of this Prospectus because Service Class shares accrued shareholder servicing fees in the amount of 0.09% for the fiscal year ended June 30, 2019.

[4] Frontegra Asset Management, Inc. (“Frontegra”), the Fund’s investment adviser, has contractually 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, AFFE and extraordinary expenses) do not exceed 0.80%, 0.95% and 1.20% of the Fund’s average daily net assets attributable to the Institutional Class, Service Class and Class Y shares, respectively. Frontegra is entitled to recoup the fees waived and/or expenses reimbursed within a three-year period from the date of the waiver or expense payment if such reimbursement will not cause the Fund’s expense ratio to exceed the lesser of: (a) the expense limitation in place at the time of the waiver and/or expense payment; or (b) the expense limitation in place at the time of the recoupment. The expense cap/reimbursement agreement will continue in effect until October 31, 2021 and may be terminated only by, or with the consent of, the Board of Directors of the Company.