Company: RFMZ
Filing Date: 2025-05-21
Form Type: 424B5
Source: 0001398344-25-009954
Chunk: 1

Company: RiverNorth Flexible Municipal Income Fund II, Inc.
Filing Date: 2025-05-21
Form: 424B5
Chunk 1
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 to the Distributor (the “Minimum Price”). The Fund and the Distributor will determine
whether any sales of Common Shares will be authorized on a particular day. The Fund and the Distributor, however, will not authorize sales
of Common Shares if the price per share of the Common Shares is less than the Minimum Price. The Fund and the Distributor may elect not
to authorize sales of Common Shares on a particular day even if the price per share of the Common Shares is equal to or greater than the
Minimum Price, or may only authorize a fixed number of Common Shares to be sold on any particular day. The Fund and the Distributor will
have full discretion regarding whether sales of Common Shares will be authorized on a particular day and, if so, in what amounts.

The Distributor may enter into
sub-placement agent agreements with one or more selected dealers. The Distributor has entered into a sub-placement agent agreement, dated
May 20, 2025 (the “Sub-Placement Agent Agreement”) with UBS Securities LLC (the “Sub-Placement Agent”) relating to
the Common Shares offered by this Prospectus Supplement and the accompanying Prospectus. In accordance with the terms of the Sub-Placement
Agent Agreement, the Fund may offer and sell its Common Shares from time to time through the Sub-Placement Agent as sub-placement agent
for the offer and sale of its Common Shares. The Fund will compensate the Distributor with respect to sales of Common Shares at a commission
rate of 1.00% of the gross proceeds of the sale of Common Shares. Out of this commission, the Distributor will compensate the Sub-Placement
Agent at a rate of up to 0.80% of the gross sales proceeds of the sale of the Common Shares sold by the Sub-Placement Agent.

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Investing in the Fund’s Common Shares involves certain risks. You could lose some or all of your investment. See “Risks” beginning on page 24 of the accompanying Prospectus. You should consider carefully these risks together with all of the other information contained in this Prospectus Supplement and the accompanying Prospectus before making a decision to purchase the Fund’s Common Shares.

Neither the Securities and Exchange Commission (“SEC”) nor any state securities commission has approved or disapproved of these securities or determined if this Prospectus Supplement or the accompanying Prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

<div align='center'>Prospectus Supplement dated May 20,
2025</div