Exhibit 5

CILCORPInc.
300 HAMILTON BLVD., SUITE 300,
PEORIA, IL  61602


                                                              December 11, 1996


CILCORP Inc.
300 Hamilton Boulevard, Suite 300
Peoria, Illinois  61602

Gentlemen:

I have examined the  registration  statement on Form S-3 proposed to be filed by
CILCORP Inc. (the "Company") with the Securities and Exchange  Commission  under
the Securities Act of 1933, for the  registration of up to 750,000 shares of the
Company's common stock, no par value (the "Additional  Common Stock") to be sold
to  security  holders  pursuant  to the  Company's  Investors  Choice  Automatic
Reinvestment  and Stock Purchase  Plan. I am also familiar with all  proceedings
relating to the sale of the Additional Common Stock.

I am of the opinion that, upon  compliance  with the relevant  provisions of the
Securities Act of 1933, upon adoption of appropriate resolutions by the Board of
Directors  of the  Company,  upon  compliance  with the formal  requirements  of
execution,  countersignature,  registration and delivery of certificates for the
Additional  Common Stock and upon the sale thereof and payment therefor upon the
terms set forth in the prospectus, the Additional Common Stock will be valid and
legally  issued,  fully paid and  non-assessable  shares of the  Company and the
holders and owners thereof will be entitled to the relative  rights set forth in
the Articles of Incorporation of the Company,  as amended,  and described in the
prospectus.

I hereby consent to the filing of this opinion as an exhibit to the registration
statement and to the use of my name as it appears in the registration statement.

                                       Very truly yours,



                                       John G. Sahn
                                       Vice President,
                                       General Counsel and Secretary