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

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the
Securities Exchange Act of 1934

Date of Report (Date of earliest event reported):  September 10, 2010

SOUTHERN MICHIGAN BANCORP, INC.
(Exact Name of Registrant as
Specified in Charter)

Michigan
(State or Other Jurisdiction
of Incorporation) 000-49722
(Commission
File Number) 38-2407501
(IRS Employer
Identification No.)

51 West Pearl Street
Coldwater, Michigan
(Address of Principal Executive Offices)
49036
(Zip Code)

Registrant's telephone number,
including area code:  (517) 279-5500

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the Registrant under any of the following provisions:

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425).

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12).

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)).

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)).

Item 7.01. Regulation FD Disclosure.

          On September 10, 2010, Southern Michigan Bancorp, Inc. mailed to its shareholders the letter furnished with this report as Exhibit 99.1, which is here incorporated by reference. This Report and the Exhibit are furnished to, and not filed with, the Commission.

Forward-Looking Statements

          The letter contains forward-looking statements that are based on management's beliefs, assumptions, current expectations, estimates and projections about the financial services industry, the economy, and Southern Michigan Bancorp, Inc. Forward-looking statements are identifiable by words or phrases such as "will," "likely," "anticipate," "uncertainty," "continuing," "strategic," "in an effort," "may" and variations of such words and similar expressions. Such statements are based upon current beliefs and expectations and involve substantial risks and uncertainties which could cause actual results to differ materially from those expressed or implied by such forward-looking statements. These statements include, among others, statements related to the state of the regional and national economic environment, the future impact on our business of a prolonged economic recession, additional legislative and regulatory burdens under the Dodd-Frank Act and the implementation of national health care legislation, and future strategic opportunities. Management's determination of the provision and allowance for loan losses involves judgments that are inherently forward-looking. Our ability to successfully implement strategic initiatives, attain efficiency targets, identify and resolve potential problem credit relationships, and build capital is not entirely within our control and is not assured. The future effect of changes in the real estate, financial and credit markets and the national and regional economy on the banking industry, generally, and Southern Michigan Bancorp, Inc., specifically, are also inherently uncertain. These statements are not guarantees of future performance and involve certain risks, uncertainties and assumptions ("risk factors") that are difficult to predict with regard to timing, extent, likelihood and degree of occurrence. Therefore, actual results and outcomes may materially differ from what may be expressed or forecasted in such forward-looking statements.

          Risk factors include, but are not limited to, the risk factors described in "Item 1A - Risk Factors" of our Annual Report on Form 10-K for the year ended December 31, 2009 and in "Part II, Item 1A - Risk Factors" of our Quarterly Report on Form 10-Q for the quarter ended June 30, 2010. These and other factors are representative of the risk factors that may emerge and could cause a difference between an ultimate actual outcome and a preceding forward-looking statement. We undertake no obligation to update or revise our forward-looking statements to reflect developments that occur or information obtained after the date of this report.

Item 9.01.	Financial Statements and Exhibits.
	(d)	Exhibits:
	99.1	Letter mailed September 10, 2010.

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.

Date:  September 10, 2010	SOUTHERN MICHIGAN BANCORP, INC.
	By	/s/ Danice L. Chartrand
		Danice L. Chartrand Senior Vice President, Chief Financial Officer, Secretary, and Treasurer

EXHIBIT INDEX

Exhibit Number	Document
99.1	Letter mailed September 10, 2010.