POWER OF ATTORNEY

Barbara R. Smith

Know all by these presents, that the undersigned
hereby constitutes and appoints each of John D.
Buchanan, Nicole V. Gersch, Jennifer S. Perry and
Owen M. Scheurich, signing singly, the
undersigned's true and lawful attorney-in-fact to:

(1)	execute for and on behalf of the undersigned,
Forms 3, 4 and 5 in accordance with Section 16(a)
of the Securities Exchange Act of 1934 and the
rules thereunder and Form 144 with respect to the
securities of Comerica Incorporated (the "Company")
beneficially owned by the undersigned in accordance
with Rule 144 under the Securities Act of 1933
(the "Securities Act");

(2)	execute for and on behalf of the undersigned
documents necessary to facilitate the filing of
Forms 3, 4 and 5 and Form 144;

(3)	do and perform any and all acts for and on
behalf of the undersigned which may be necessary
or desirable to complete and execute any such Form
3, 4 or 5 or Form 144, complete and execute any
amendment or amendments thereto, and timely file
such form with the United States Securities and
 Exchange Commission and any stock exchange or
similar authority; and

(4)	take any other action of any type whatsoever
in connection with the foregoing which, in the
opinion of such attorney-in-fact, may be of benefit
to, in the best interest of, or legally required by,
the undersigned, it being understood that the
documents executed by such attorney-in-fact on
behalf of the undersigned pursuant to this Power of
Attorney shall be in such form and shall contain
such terms and conditions as such attorney-in-fact
may approve in such attorney-in-fact's discretion.

The undersigned hereby grants to each such attorney
-in-fact full power and authority to do and perform
any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of
any of the rights and powers herein granted, as
fully to all intents and all purposes as the
undersigned might or could do if personally present,
with full power of substitution or revocation,
hereby ratifying and confirming all that such
attorney-in-fact, or such attorney-in-fact's
substitute or substitutes, shall lawfully do or
cause to be done by virtue of this power of attorney
and the rights and powers herein granted.  The
undersigned acknowledges that the foregoing attorneys
-in-fact, in serving in such capacity at the request
of the undersigned, are not assuming, nor is the
Company assuming, any of the undersigned's respons-
ibilities to comply with Section 16 of the Securities
Exchange Act of 1934 or Rule 144 under the Securities
Act.

The termination of any attorney-in-fact's employment
by the Company, however caused, shall operate as a
termination of his or her powers and authorities
hereunder, but shall not affect the powers and
authorities herein granted to any other party.

This Power of Attorney shall remain in full force
and effect until six months from the date the
undersigned resigns, retires or is removed from the
Board of Directors of the Company, unless earlier
revoked by the undersigned in a signed writing
delivered to the foregoing attorneys-in-fact
at the then current mailing address of the
Corporate Legal Department of Comerica
Incorporated.

All Powers of Attorney previously granted in
connection with the foregoing matters hereby are
canceled and revoked.

IN WITNESS WHEREOF, the undersigned has caused this
Power of Attorney to be executed and made effective
as of the 7th day of November, 2017.




/s/ Barbara R. Smith
Barbara R. Smith