EXHIBIT 5

           Opinion and Consent of Foster, Swift, Collins & Smith, P.C.

                                  Exhibit 5 - 1


October 12, 2007

IBT Bancorp, Inc.
200 East Broadway
Mt. Pleasant, MI 48858

Ladies and Gentlemen:

Re:   Registration Statement on Form S-4
      514,809 Shares of Common Stock, No Par Value Per Share

We are counsel to IBT Bancorp, Inc. ("IBT") in connection with the registration
under the Securities Act of 1933, as amended (the "Securities Act"), of shares
of IBT common stock, no par value per share ("Common Stock"), pursuant to a
registration statement on Form S-4 (the "Registration Statement") filed with the
Securities and Exchange Commission (the "Commission") on or about October 15,
2007.

We are familiar with the proceedings taken by IBT in connection with the
authorization of up to 514,809 shares of Common Stock to be issued to the
shareholders of Greenville Community Financial Corporation. We have examined
such documents, records and matters of law as we have deemed necessary for
purposes of this opinion. In our examination, we have assumed the genuineness of
all signatures, the legal capacity of all natural persons, the authenticity of
all documents submitted to us as originals, the conformity to original documents
of all documents submitted to us as certified or photostatic copies, and the
authenticity of the originals of such copies.

Based upon the foregoing, we are of the opinion that the Common Stock will be,
when duly registered under the Securities Act and issued and delivered as
described in the Registration Statement, legally issued, fully paid and
nonassessable.

We consent to the filing of this opinion as an exhibit to the Registration
Statement and to the references to our firm in the Registration Statement.

This opinion is rendered for the purposes of Item 21 of Form S-4 and Item 601 of
Regulation S-K and may be relied upon only by you and the Commission and may not
be used, quoted, referred to or filed for any other purpose without our prior
written permission.

Very truly yours,

FOSTER, SWIFT, COLLINS & SMITH, P.C.

/s/ Foster, Swift, Collins & Smith, P.C.

                                   Exhibit 5 - 2