UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13D

Information To Be Included in Statements Filed Pursuant to § 240.13d-1(a) and

Amendments Thereto Filed Pursuant to § 240.13d-2(a)

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because off §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.  ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

13D

13D

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Item 1. Security and Issuer

This Schedule 13D is being filed by the undersigned with respect to common stock, par value $0.0001 per share (the “Common Stock”), of InfuSystem Holdings, Inc., a Delaware corporation (the “Issuer”). The address of the Issuer is 31700 Research Park Drive, Madison Heights, Michigan 48071.

Item 2. Identity and Background

(a-f) This Schedule 13D is being filed by Tripletail, LLC, a Florida limited liability company (“Tripletail”) and Sean McDevitt, a United States citizen, (“Mr. McDevitt” and, together with “Tripletail”, the “Reporting Persons”), Chief Executive Officer and Chairman of the Board of the Issuer. Mr. McDevitt’s principal place of business is at 31700 Research Park Drive, Madison Heights, Michigan 48071. Tripletail is a holding company of which Mr. McDevitt is the sole member.

During the last five years, neither Reporting Person has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

During the last five years, neither Reporting Person has been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and was not and is not as a result of any such proceeding subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

Item 3. Source and Amount of Funds or Other Consideration

The Reporting Persons acquired the 1,726,544 shares of Common Stock through (i) a series of grants of an aggregate of 1,720,044 shares from the Issuer as compensation for Mr. McDevitt’s service as an officer and director and (ii) purchases of 6,500 shares in the open market.

Item 4. Purposes of Transactions

Mr. McDevitt is an officer and director of the Issuer and acquired the shares of Common Stock for investment purposes.

Item 5. Interest in Securities of the Issuer

(a, b) On July 24, 2006, the Issuer granted (the “Grant”) Mr. McDevitt the right to receive a grant of shares of Common Stock following the Issuer’s consummation of a business combination meeting certain criteria. On October 25, 2007, the Issuer completed its acquisition of InfuSystem, Inc. (the “Acquisition”), which satisfied the conditions of the Grant. In addition, as a result of the Acquisition, warrants to purchase 1,195,858 shares of Common Stock at an exercise price of $5.00 per share, which Mr. McDevitt had purchased, became exercisable upon completion of the Acquisition. On February 23, 2009, the Issuer issued 1,234,044 shares of Common Stock to Tripletail in fulfillment of the Grant. On April 11, 2011, the warrants, none of which had ever been exercised, expired.

As of the date hereof, Tripletail directly holds 1,234,044 shares of Common Stock of the Issuer, constituting approximately 5.8% and Mr. McDevitt directly holds an additional 492,500 shares and through his control of Tripletail, beneficially owns the 1,234,044 shares held by Tripletail, for an aggregate of 1,726,544 shares of Common Stock, constituting approximately 8.1% of the Common Stock of the Issuer, in each case, based upon an aggregate of 21,244,916 shares of Common Stock stated to be outstanding as of November 8, 2011 by the Issuer in the Issuer’s Form 10-Q for the quarter ended September 30, 2011, filed with the United States Securities and Exchange Commission (the “Commission”). Mr. McDevitt is the sole member of Triple Tail.

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Tripletail has the sole power to vote or direct the vote of 0 shares of Common Stock, has the shared power to vote or direct the vote of 1,234,044 shares of Common Stock; has sole power to dispose or direct the disposition of 0 shares of Common Stock; and has shared power to dispose or direct the disposition of 1,234,044 shares of Common Stock. Mr. McDevitt has the sole power to vote or direct the vote of 492,500 shares of Common Stock; has the shared power to vote or direct the vote of 1,234,044 shares of Common Stock; has sole power to dispose or direct the disposition of 492,500 shares of Common Stock; and has shared power to dispose or direct the disposition of 1,234,044 shares of Common Stock.

Item 6. Contracts, Arrangements, Understandings or Relationships with respect to the Issuer

Pursuant to the Amended and Restated Registration Rights Agreement by and among the Issuer, Mr. McDevitt and certain other stockholders of the Issuer dated October 17, 2007 (the “Registration Rights Agreement”), Mr. McDevitt has the right to require the Issuer to register certain of the shares of Common Stock beneficially owned by him under the Securities Act of 1933 pursuant to customary demand registration rights, piggyback registration rights and other registration rights under the terms and conditions specified therein.

Pursuant to a Share Award Agreement between the Issuer and Mr. McDevitt dated April 6, 2010, Mr. McDevitt was awarded, as incentive compensation for his services as Chief Executive Officer, the right to receive up to an aggregate of 2,000,000 shares of Common Stock in increments upon the attainment of specified trading price levels from $5.00 to $15.00. All of the shares of Common Stock will vest immediately upon the occurrence of a change of control of the Company.

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Item 7. Materials to Be Filed as Exhibits

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SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: January 27, 2012

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INDEX TO EXHIBITS

EXHIBIT A

AGREEMENT OF JOINT FILING

In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the undersigned hereby confirm the agreement by and among them to the joint filing on behalf of them of the Statement on Schedule 13D with respect to the securities of the above referenced issuer and any and all amendments thereto and that this Agreement be included as an Exhibit to such filing. This Agreement may be executed in any number of counterparts each of which shall be deemed to be an original and all of which together shall be deemed to constitute one and the same Agreement.

IN WITNESS WHEREOF, the undersigned hereby execute this Agreement as of January 27, 2012.