UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR

15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of October 2025

Commission File Number: 001-34934

COSTAMARE INC.

(Translation of registrant’s name into English)

7 rue du Gabian, MC 98000 Monaco

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☒ Form 40-F ☐

INCORPORATION BY REFERENCE

The information contained in this Report on Form 6-K shall be incorporated by reference into our registration statements on Form F-3, as filed with the U.S. Securities and Exchange Commission on July 6, 2016 (File No. 333-212415) and March 29, 2024 (File No. 333-278366) to the extent not superseded by information subsequently filed or furnished (to the extent we expressly state that we incorporate such furnished information by reference) by us under the Securities Act of 1933 or the Securities Exchange Act of 1934, in each case as amended.

EXHIBIT INDEX

99.1	Statement of Designation of Rights, Preferences and Privileges of Series F Preferred Stock of Costamare Inc.
99.2	Stock Subscription Agreement, dated as of October 15, 2025, between Costamare Inc. and Konstantinos Konstantakopoulos

99.1	First Amendment, dated as of October 21, 2025, to Shareholders Rights Agreement, dated as of October 19, 2010, by and between Costamare Inc. and Equiniti Trust Company, LLC (formerly known as American Stock Transfer & Trust Company, LLC)

Monaco, October 1521, 2025 – On October 21, 2025, Costamare Inc. (~~“Costamare” or~~ the “Company”) (NYSE: CMRE) ~~announced~~entered ~~today~~into ~~that~~a itFirst ~~has~~Amendment ~~entered~~(the ~~into~~“Amendment”) ato ~~Stock~~the ~~Subscription~~Shareholders Rights Agreement, dated as of October 19, 2010, by and between the Company and Equiniti Trust Company, LLC (formerly known as American Stock Transfer & Trust Company, LLC), as rights agent (the “~~Purchase~~ Rights Agreement”). ~~with~~The ~~Konstantinos~~Amendment ~~Konstantakopoulos~~modifies the definition of Acquiring Person to provide that, ~~pursuant~~subject to ~~which~~certain Mrexceptions, the Rights (as defined in the Rights Agreement) become exercisable upon a “U.S. ~~Konstantakopoulos~~Person” ~~will~~(as ~~purchase~~defined ~~1,200~~below) ~~shares~~becoming the beneficial owner of a5% ~~new~~or ~~series~~more of ~~high-vote,~~the Company’s common stock then outstanding. For non-~~economic~~U.S. ~~preferred~~Persons, ~~stock~~the triggering threshold remains unchanged. “U.S. Person” is generally defined to mean any person who or which is, or the ultimate parent or beneficial owner of such person who or which is, organized under the laws of the United States of America or any State of the United States of America (or in the ~~“Series~~case Fof ~~Preferred~~a ~~Stock”~~natural person, is a legal resident thereof), ~~for~~except anas ~~aggregate~~may ~~purchase~~be ~~price~~exempted by the Board. Any U.S. person that beneficially owned 5% or more of Company's ~~$1,200~~ common stock as of the public announcement of the Amendment will not be deemed to be an Acquiring Person so long as such person does not exceed its existing percentage ownership (other than subject to customary exceptions).

~~Each~~In ~~share~~addition, ofin ~~Series~~connection Fwith ~~Preferred~~the ~~Stock~~entry ~~shall~~into ~~entitle~~the ~~Mr.~~Amendment, ~~Konstantakopoulos~~the toBoard ~~50,000~~of ~~votes~~Directors on(the ~~all~~“Board”) ~~matters~~of ~~submitted~~the toCompany awill ~~vote~~grant ofan ~~the~~exemption ~~shareholders~~from of the ~~Company~~definition of U. ~~The~~S. ~~Series~~Persons Fany ~~Preferred~~existing ~~Stock~~U.S.-based ~~were~~shareholders ~~established~~who ~~in connection~~or ~~with~~which ~~the~~(i) ~~announcement~~currently onbeneficially ~~October~~own ~~10,~~5% ~~2025,~~or bymore of the ~~Ministry~~Company’s ofcommon ~~Transport~~stock in(as ~~China~~evidenced ~~relating~~by tosuch ~~the~~holder’s ~~collection~~public offilings ~~special~~as ~~port~~filed ~~fees~~with ~~from~~the U.S.~~-linked~~ ~~vessels.~~Securities ~~While~~and Exchange Commission as of the ~~Company~~public ~~does~~announcement ~~not~~of ~~believe~~the Amendment) and (ii) are passive investors that ~~its~~have ~~vessels~~reported and are ~~subject~~entitled to ~~the collection~~report ofbeneficial ~~special~~ownership ~~port~~under ~~fees,~~Schedule 13G under the ~~issuance~~Securities Exchange Act of ~~the~~1934, ~~Series~~as Famended ~~Preferred~~(the “Exchange ~~Stock~~Act”), ~~ensures~~but ~~that~~only itso islong ~~not~~as ~~possible~~such ~~for~~holder ~~U.S.~~is ~~persons~~eligible to ~~control~~report ~~over~~ownership ~~25%~~on ofSchedule 13G under the ~~voting~~Exchange ~~power~~Act ofand ~~the~~such ~~Company~~holder ~~because,~~has ~~following~~not ~~the~~reported ~~completion~~and ofis ~~the~~not ~~purchase~~required byto ~~Mr. Konstantakopoulos,~~report ~~members~~such ofownership ~~the~~on ~~Konstantakopoulos~~Schedule ~~family~~13D ~~(none~~under ofthe ~~whom~~Exchange ~~are~~Act ~~U.S.~~and such ~~persons)~~holder ~~will~~does ~~control~~not ~~approximately~~hold ~~75.7%~~shares of the Company’s ~~issued~~common ~~and~~stock ~~outstanding~~on ~~voting~~behalf ~~rights.~~of ~~Prior~~any other person who is required to ~~the~~report ~~issuance~~on ofSchedule 13D under the ~~shares~~Exchange ofAct ~~Series~~(an F“Existing ~~Preferred~~U.S. ~~Stock pursuant~~Passive toInvestor”), ~~the~~but ~~Purchase~~solely ~~Agreement,~~to the ~~Konstantakopoulos~~extent ~~family~~such ~~controlled~~holder ~~approximately~~does not ~~63.~~beneficially own 6.5% or more of the Company’s ~~issued~~common ~~and outstanding voting rights~~stock.

The ~~Series~~Rights FAgreement ~~Preferred~~otherwise ~~Stock~~remains ~~shall~~unmodified ~~not have any dividend or distribution rights,~~ and ~~shall~~continues not be entitled to any distributions upon any liquidation, dissolution or winding up of the Company other than its par value. All shares of the Series F Preferred Stock are subject to redemption by the Company at any time in ~~the~~full ~~sole~~force ~~discretion of the independent members of the Board of Directors of the Company (or a committee comprised thereof)~~ and ~~without~~effect ~~the consent~~in ofaccordance ~~the~~with ~~holders~~its ~~of Series F Preferred Stock, for a redemption price equal to $1 per share~~terms. Effective on the date that is the fifth anniversary of the date of issuance of the shares of Series F Preferred Stock, all rights and powers of any such shares that remain outstanding will automatically terminate and be of no further force or effect.

The ~~Audit~~Board ~~Committee~~approved ofthe entry into the ~~Company,~~Amendment ~~comprised~~in ~~solely~~an effort to protect stockholder value in light of ~~independent~~recent ~~and~~developments ~~disinterested~~arising ~~directors~~from the announcement on October 10, ~~reviewed~~2025 by the ~~Purchase~~Ministry ~~Agreement~~of ~~and~~Transport of the People’s ~~Statement~~Republic of ~~Designation~~China ~~establishing~~relating to the ~~Series~~collection Fof ~~Preferred~~special ~~Stock~~port fees from US-linked vessels and ~~unanimously~~ ~~recommended~~the ~~that~~subsequent regulations and guidance promulgated related thereto, and to strengthen the ~~Board~~Company’s ofability ~~Directors~~to ofrespond to any U.S. Persons who may seek to acquire an ownership interest in the Company ~~approve~~in order to influence the ~~designation~~Company’s ability to adhere to such regulations and ~~issuance~~guidance. ofThe Company is closely monitoring the ~~Series~~ongoing Fregulatory ~~Preferred~~developments ~~Stock~~referenced above and currently expects to rescind the ~~execution~~Amendment and reinstate the prior terms of the ~~Purchase~~Rights Agreement if and once the Board determines that such changes are no longer necessary.

The ~~terms~~foregoing ofis ~~the Series F Preferred Stock are set forth in~~ a ~~Statement~~summary of ~~Designation~~the terms of ~~Rights~~the Amendment, ~~Preferences~~does ~~and~~not ~~Privileges~~purport ofto ~~Series~~be Fcomplete ~~Preferred~~and ~~Stock~~is ofqualified ~~the~~in ~~Company,~~its ~~dated~~entirety asby ofreference ~~October~~to ~~15, 2025 (~~the ~~“Statement of Designation”)~~Amendment, a copy of which is attached ~~hereto~~ as Exhibit 99.1 and incorporated by reference into this report.

Forward-Looking Statements

This report contains “forward-looking statements”. In some cases, you can identify these statements by forward-looking words such as “believe”, “intend”, “anticipate”, “estimate”, “project”, “forecast”, “plan”, “potential”, “may”, “should”, “could” and “expect” and similar expressions. These statements are not historical facts but instead represent only the Company’s belief regarding future results, many of which, by their nature, are inherently uncertain and outside of the Company’s control. It is possible that actual results may differ, possibly materially, from those anticipated in these forward-looking statements. For a discussion of some of the risks and important factors that could affect future results, see the discussion in the Company’s Annual Report on Form 20-F (File No. 001-34934) under the caption “Risk Factors”.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	COSTAMARE INC.
Date: October 15, 2025	By:	/s/ Gregory G. Zikos
		Name:	Gregory G. Zikos
		Title:	Chief Financial Officer

Date: October 21, 2025

COSTAMARE INC.

By:	/s/ Gregory G. Zikos
	Name:	Gregory G. Zikos
	Title:	Chief Financial Officer

Filing Compare · Costamare Inc.