S-8

QuickLinks -- Click here to rapidly navigate through this document

As filed with the Securities and Exchange Commission on October 22, 2003

Registration No. 333-          

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM S-8
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

MEDAMICUS, INC.
(Exact name of registrant as specified in its charter)

Minnesota
(State or other jurisdiction of
incorporation or organization) 41-1533300
(I.R.S. Employer
Identification No.)

15301 Highway 55 West
Plymouth, MN 55447
(Address of Principal Executive Offices and zip code)

MEDAMICUS, INC.
1999 INCENTIVE STOCK OPTION PLAN
(Full title of the Plan)

James D. Hartman
Chief Executive Officer
Medamicus, Inc.
15301 Highway 55 West
Plymouth, MN 55447
(763) 559-2613
(Name, address, including zip code and
telephone number of agent for service) Copy to:
Thomas G. Lovett, IV
Rebecca B. Sandberg
Lindquist & Vennum P.L.L.P.
4200 IDS Center
80 South Eighth Street
Minneapolis, MN 55402
(612) 371-3211

CALCULATION OF REGISTRATION FEE

Title of Securities to be Registered	Proposed Maximum Amount to be Registered	Proposed Maximum Offering Price Per Share(1)	Aggregate Offering Price(1)	Amount of Registration Fee
Common Stock, $.01 par value	500,000 shares(2)	$11.34	$5,670,000	$458.70

(1)

Estimated solely for the purpose of determining the registration fee pursuant to Rule 457(c) and (h) and based upon the average high and low price of the Company's Common Stock on the Nasdaq National Market on October 17, 2003.

(2)

400,000 shares were originally registered on Form S-8 (No. 333-57938) on March 30, 2001.

INCORPORATION OF CONTENTS OF REGISTRATION STATEMENT
BY REFERENCE

        A Registration Statement on Form S-8 (File No. 333-57938) was filed with the Securities and Exchange Commission on March 30, 2001 covering the registration of 400,000 shares initially authorized for issuance under the 1999 Incentive Stock Option Plan ("Plan"). Pursuant to General Instruction E of Form S-8, this Registration Statement is being filed to register an additional 500,000 shares authorized under the Plan. Amendments to the Plan to increase the number of shares under the Plan by 300,000 and 200,000 shares were authorized by the Company's Board of Directors and were approved by the shareholders on April 24, 2003 and October 21, 2003, respectively. The contents of the prior Registration Statement are incorporated herein by reference.

PART I

        Pursuant to the Note to Part I of Form S-8, the information required by Items 1 and 2 of Form S-8 is not filed as a part of this Registration Statement and such information will be sent or given to employees as specified by Rule 428(b)(1).

PART II

Item 3. Incorporation of Documents by Reference.

        The following documents filed with the Securities and Exchange Commission are hereby incorporated by reference herein:

        (a)   The Annual Report of the Company on Form 10-KSB for the year ended December 31, 2002.

        (b)   The Definitive Proxy Statement dated March 21, 2003 for the Annual Meeting of Shareholders held on April 24, 2003.

        (c)   The Quarterly Reports of the Company on Form 10-Q for the quarters ended March 31, 2003 and June 30, 2003.

        (d)   The Current Reports of the Company on Form 8-K filed on February 11, 2003, April 15, 2003 and July 22, 2003.

        (e)   The description of the Company's common stock as set forth in the Company's Registration Statement on Form S-4 (Registration No. 333-108404) filed on August 29, 2003, including any amendment or report filed for the purpose of updating such description.

        All documents subsequently filed by the Company pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934, prior to the filing of a post-effective amendment which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference in this Registration Statement and to be a part hereof from the date of filing of such documents.

Item 4. Description of Securities.

        Not applicable.

Item 5. Interests of Named Experts and Counsel.

        Not applicable.

2

Item 6. Indemnification of Directors and Officers.

        Section 302A.521 of the Minnesota Business Corporation Act requires us to indemnify a person made or threatened to be made a party to a proceeding by reason of the former or present official capacity of the person with respect to us, against judgments, penalties, fines, including reasonable expenses, if such person (1) has not been indemnified by another organization or employee benefit plan for the same judgments, penalties, fines, including, without limitation, excise taxes assessed against the person with respect to an employee benefit plan, settlements, and reasonable expenses, including attorneys' fees and disbursements, incurred by the person in connection with the proceeding with respect to the same acts or omissions; (2) acted in good faith; (3) received no improper personal benefit and a statutory procedure has been followed in the case of any conflict of interest by a director; (4) in the case of a criminal proceeding, had no reasonable cause to believe the conduct was unlawful; (5) in the case of acts or omissions occurring in the person's performance in the official capacity of director, or for a person not a director, in the official capacity of officer, committee member, employee or agent, reasonably believed that the conduct was in the best interests of the company, or, in the case of performance by a director, officer, employee or agent of the company as a director, officer, partner, trustee, employee or agent or another organization or employee benefit plan, reasonably believed that the conduct was not opposed to the best interest of the Company. In addition, Section 302A.521, subd. 3 requires payment by us, upon written request, of reasonable expenses in advance of final disposition in certain instances. A decision as to indemnification is made by a disinterested majority of the Board of Directors present at a meeting at which a disinterested quorum is present, by a designated committee of the Board, by special legal counsel, by the shareholders, or by a court.

        As permitted by the Minnesota Business Corporation Act, our Articles of Incorporation eliminate the liability of our directors for monetary damages arising from any breach of fiduciary duties as a member of our Board of Directors (except as expressly prohibited by Minnesota Business Corporation Act, Section 302A.251, Subd. 4).

        For information regarding our undertaking to submit to adjudication the issue of indemnification for violation of the securities laws, see Item 9 hereof.

Item 7. Exemption from Registration Claimed.

        Not applicable.

Item 8. Exhibits.

Exhibit
4.1	Medamicus, Inc. Stock Option Incentive Plan
5.1	Opinion of Lindquist & Vennum P.L.L.P.
23.1	Consent of Lindquist & Vennum P.L.L.P. (included in Exhibit 5.1)
23.2	Consent of McGladrey & Pullen, LLP, certified independent public accountants
24.1	Power of Attorney (set forth on signature page hereof)

3

Item 9. Undertakings.

        (a)   The undersigned registrant hereby undertakes:

        (1)   To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

        (iii)  To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement.

        (2)   That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

        (3)   To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

        (b)   The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant's annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

        (h)   Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers, and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer, or controlling person of the registrant in the successful defense of any action, suit, or proceeding) is asserted by such director, officer, or controlling person connected with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

4

SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Plymouth, State of Minnesota, on October 21, 2003.

MEDAMICUS, INC.
By	/s/  JAMES D. HARTMAN James D. Hartman, President and Chief Executive Officer (Principal Executive Officer)

POWER OF ATTORNEY

        We, the undersigned officers and directors of Medamicus, Inc., a Minnesota corporation, do hereby make, constitute and appoint James D. Hartman and Mark C. Kraus, or either of them, as our true and lawful attorneys-in-fact and agents, each with full power of substitution and resubstitution, for us and in our name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this registration statement and to file the same, with all exhibits and other supporting documents thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting upon the attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing necessary or incidental to the performance and execution of the powers herein expressly granted. This power of attorney shall remain in effect until revoked in writing by the undersigned.

        Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed below by the following persons in the capacities indicated on the 21st day of October, 2003.

Signature	Title
/s/  JAMES D. HARTMAN James D. Hartman	Chief Executive Officer, President, Chief Financial Officer, Secretary and Director (Principal Executive Officer, Principal Financial Officer)
/s/  RICHARD F. SAUTER Richard F. Sauter	Director
/s/  THOMAS L. AUTH Thomas L. Auth	Director
/s/  MICHAEL D. DALE Michael D. Dale	Director
/s/  ALBERT EMOLA Albert Emola	Director

5

QuickLinks

INCORPORATION OF CONTENTS OF REGISTRATION STATEMENT BY REFERENCE
PART I
PART II
SIGNATURES
POWER OF ATTORNEY

EX-4.1

QuickLinks -- Click here to rapidly navigate through this document

Exhibit 4.1

MEDAMICUS, INC. 1999 INCENTIVE STOCK OPTION PLAN

(as amended through October 21, 2003)

        1.    Purpose.    The purpose of this Plan is to further the growth and general prosperity of MedAmicus, Inc., the Company, by enabling the employees of the Company, who have been or will be given responsibility for the affairs of the Company, to acquire shares of its common stock under the terms and conditions and in the manner set forth by this Plan, increasing their personal involvement in the Company and to enable the Company to obtain and retain the services of those employees.

        2.    Administration.    This Plan shall be administered by a Committee of at least two (2) Directors who are disinterested administrators within the meaning of Section 16 of the Securities Exchange Act of 1934 and the rules, regulations and interpretations promulgated thereunder.

        Each option granted will be evidenced by a written agreement (Stock Option Agreement) and a document containing the terms and conditions of the Plan.

        3.    Eligibility and Participation.    Employees eligible to receive options under the Plan shall be key personnel including officers of the Company and directors who are also employees of the Company. The Committee shall allot to such participant options to purchase shares as the Committee shall from time to time determine: provided, however, that no employee shall be allotted an option for any greater number of shares than would result in him owning directly or indirectly, more than 10% of the total combined voting power or value of the stock of the Company or any of its subsidiaries unless the option price is at least 85% of the market value of the stock on the date of grant, and the option is, by its terms, not exercisable after six (6) years from the date of grant.

        4.    Shares Subject to Plan.    Subject to adjustment as provided in Section 5, an aggregate of up to 900,000⁽¹⁾ shares of the Common Stock of the Company shall be subject to the Plan and the Committee is authorized to grant options hereunder with respect to such number of shares. Any unsold shares subject to an option under the Plan which for any reason expires or otherwise terminates may again be made subject to option under the Plan at the discretion of the Committee.

(1)

The Plan originally authorized 400,000 shares of Common Shares for issuance. An amendment to the Plan to increase the number of shares under the Plan by 300,000 was authorized by the Board on February 6, 2003 and approved by the shareholders on April 24, 2003. An amendment to the Plan to increase the number of shares under the Plan by 200,000 was authorized by the Board of Directors on July 21, 2003 and approved by the shareholders on October 21, 2003.

        5.    Adjustments Upon Changes in Capitalization.    In the event of a merger, consolidation, reorganization, stock dividend, stock split, or any other change in corporate structure or capitalization affecting the Company's common shares, appropriate adjustment shall be made in the maximum number of shares available under the Plan or to any one individual and in the number, kind, option, price, etc. of shares subject to options granted under the Plan.

        6.    Terms and Conditions of Options.    The Committee shall have power subject to the limitations contained in the Plan, to prescribe any terms and conditions in respect to the granting or exercise of any option under the Plan and in particular shall prescribe the following terms and conditions:

        (a)   Each option shall state the number of shares to which it pertains.

        (b)   Each option shall be granted within ten years of the date the Plan is adopted.

        (c)   Each option shall be exercisable only within six years of the date of grant.

        (d)   The purchase price, which shall be at least 85% of the fair market value of the shares at such time as the option is granted and shall not be less than the par value of the shares sold.

        (e)   An option may be exercised at any time after the date of grant subject to the provisions of section 6(f) of the Plan with respect to all or part of the shares covered by the option. An option may not be exercised for fractional shares of stock.

        In the event the Company or the stockholders of the Company enter into an agreement to dispose of all or substantially all of the assets or stock of the Company by means of a sale, merger, reorganization, liquidation or otherwise, an option shall become immediately exercisable with respect to the full number of shares.

        (f)    An option shall be exercised when written notice of such exercise has been given to the Company at its principle business office by the person entitled to exercise the option and full payment for the shares has been received by the Company. Until the stock certificates are issued, no right to vote, receive dividends, or any other rights as a shareholder shall exist with respect to optioned shares, notwithstanding the exercise of the option.

        (g)   An option may be exercised by the optionee only while he is, and has continually been, since the date of the grant of the option, an employee of the Company or within three months following termination of employment (for reasons other than death, disability or termination for cause).

        If the continuous employment of an optionee terminates by reason of his death, options which the deceased employee would be entitled to exercise as of the date of death may be exercised within one year following the date of death by the person to whom his rights under such option shall have passed by will or by the laws of descent and distribution, but in no event later than the expiration of the option.

        If the continuous employment of an optionee terminates by reason of disability, options which the disabled employee would be entitled to exercise as of the date of termination of employment may be exercised within one year following the date of termination, but in no event later than the expiration of the option.

        If the continuous employment of an optionee terminates for cause, any options which have not been exercised as of the date of termination shall be cancelled.

        7.    Options Not Transferable.    No option granted under the Plan will be transferrable by the optionee, either voluntarily or involuntarily, except by will or the laws of descent and distribution, and then only to the extent provided in Section 6 hereof, or pursuant to a qualified domestic relations order (as defined by the Internal Revenue Code of 1986, as amended, or Title I of the Employee Retirement Income Security Act and the rules thereunder.)

        8.    Amendment or Termination of the Plan.    The Board of Directors may amend the Plan from time to time as it deems advisable. The Board of Directors may at any time terminate the Plan, provided that any termination of the Plan shall not affect options already granted. The options shall remain in full force and effect as if the Plan had not been terminated.

        9.    Agreement and Representation of Employee.    As a condition to the exercise of any option or portion thereof, the Company may require the person exercising the option to represent and warrant at the time of any exercise that the shares are being purchased only for investment and without any present intention to sell or distribute the shares if in the option of counsel for the Company such representation is required under the Securities Act of 1933, or any other applicable law, regulation or rule of any governmental agency.

        In the event legal counsel to the Company renders an option to the Company that shares for options exercised pursuant to this Plan cannot be issued to the optionee because such act would violate the applicable Federal or State securities law, then and in that event, the optionee agrees that the Company shall not be required to issue the shares to the optionee tendered to the Company upon exercise of the option.

        10.    Effectiveness and Termination of the Plan.    The Plan shall become effective upon adoption by the Board of Directors and shall be subject to approval of the stockholders of MedAmicus, Inc. within 12 months of adoption. The Plan shall terminate on the earliest of:

        (a)   the date when all the common shares available under the Plan shall have been acquired through exercising the options granted under the Plan,

        (b)   August 1, 2009,

        (c)   such other date as the Board may determine.

        11.    Form of Option.    Options may be issued by the execution of the MedAmicus, Inc. form entitled "Stock Option Agreement."

QuickLinks

MEDAMICUS, INC. 1999 INCENTIVE STOCK OPTION PLAN

EX-5.1

Exhibit 5.1

October 21, 2003

Medamicus, Inc.
15301 Highway 55 West
Plymouth, MN 55447

Re:

Opinion of Counsel as to Legality of 500,000 Shares of Common Stock to be registered under the Securities Act of 1933, as amended.

Ladies and Gentlemen:

        This opinion is furnished in connection with the registration under the Securities Act of 1933, as amended, on Form S-8 of 500,000 shares of Common Stock, $.01 par value, of Medamicus, Inc. (the "Company") offered to officers, consultants and other key employees of the Company pursuant to the Medamicus, Inc. 1999 Incentive Stock Option Plan (the "Plan"). These shares are in addition to the 400,000 shares originally offered pursuant to the Plan and registered on a previous Registration Statement on Form S-8 (File No. 333-57938).

        As counsel for the Company, we advise you that it is our opinion, based on our familiarity with the affairs of the Company and upon our examination of pertinent documents, that the additional 500,000 shares of Common Stock to be offered by the Company under the Plan, will, when paid for and issued in accordance with the terms of the Plan, be validly issued and lawfully outstanding, fully paid and nonassessable shares of Common Stock of the Company.

        The undersigned hereby consents to the filing of this opinion with the Securities and Exchange Commission as an Exhibit to the Registration Statement with respect to said shares of Common Stock under the Securities Act of 1933, as amended.

Very truly yours,

LINDQUIST & VENNUM P.L.L.P.

/s/ Lindquist & Vennum P.L.L.P.

EX-23.2

QuickLinks -- Click here to rapidly navigate through this document

Exhibit 23.2

INDEPENDENT AUDITORS' CONSENT

We consent to the incorporation by reference in the Registration Statement on Form S-8 of Medamicus, Inc. of our report dated January 17, 2003 with respect to the financial statements of Medamicus, Inc. included in its Annual Report on Form 10-KSB for the year ended December 31, 2002, filed with the Securities and Exchange Commission.

McGladrey & Pullen, LLP

Minneapolis, Minnesota
October 22, 2003

QuickLinks

INDEPENDENT AUDITORS' CONSENT