Exhibit 10.1

TWELFTH AMENDMENT AGREEMENT
This TWELFTH AMENDMENT AGREEMENT (this “Amendment”) is made as of the 4th day of
August, 2017 among:
(a)    CORE MOLDING TECHNOLOGIES, INC., a Delaware corporation (“Core Molding”);

(b)    CORECOMPOSITES DE MEXICO, S. DE R.L. DE C.V., a sociedad de
responsabilidad limitada de capital variable organized under the laws of Mexico
(“Core Mexico” and, together with Core Molding, collectively, “Borrowers” and,
individually, each a “Borrower”);

(c)    the Lenders, as defined in the Credit Agreement, as hereinafter defined;
and

(d)    KEYBANK NATIONAL ASSOCIATION, as the lead arranger, sole book runner and
administrative agent for the Lenders under the Credit Agreement (“Agent”).

WHEREAS, the Borrowers, Agent and the Lenders are parties to that certain Credit
Agreement, dated as of December 9, 2008 (as amended and as the same may from
time to time be further amended, restated or otherwise modified, the “Credit
Agreement”);

WHEREAS, the Borrowers, Agent and the Lenders desire to amend the Credit
Agreement to modify certain provisions thereof;

WHEREAS, each capitalized term used herein and defined in the Credit Agreement,
but not otherwise defined herein, shall have the meaning given such term in the
Credit Agreement; and

WHEREAS, unless otherwise specifically provided herein, the provisions of the
Credit Agreement revised herein are amended effective as of the date of this
Amendment;

NOW, THEREFORE, in consideration of the premises and of the mutual covenants
herein and for other valuable consideration, the receipt and sufficiency of
which is hereby acknowledged, the Borrowers, Agent and the Lenders agree as
follows:

1.    Amendment to Definition in the Credit Agreement. Section 1.1 of the Credit
Agreement is hereby amended to delete the definition of “Consolidated Fixed
Charges” therefrom and to insert in place thereof the following:

“Consolidated Fixed Charges” means, for any period, on a Consolidated basis and
in accordance with GAAP, the aggregate, without duplication, of (a) Consolidated
Interest Expense (including, without limitation, the “imputed interest” portion
of Capitalized Lease Obligations, synthetic leases and asset securitizations, if
any, but excluding any measure of ineffectiveness related to interest rate swaps
and amortization of loan origination and issuance costs), (b) Consolidated
Income Tax Expense, (c) scheduled principal payments of long-term Consolidated
Funded Indebtedness (other than scheduled principal payments of the Mexican Loan
that were prepaid by Core Molding or any of its Subsidiaries one year (or
longer) prior to the due date of such principal payment), (d) Capital
Distributions made in an aggregate amount in excess of Two Million Dollars
($2,000,000), and (e) Consolidated Unfunded Capital Expenditures.

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2.    Amendment to Restricted Payment Covenant Provisions. Article V of the
Credit Agreement is hereby amended to delete Section 5.15 therefrom and to
insert in place thereof the following:

Section 5.15. Restricted Payments No Company shall make or commit itself to make
any Restricted Payment at any time, except that, so long as no Default or Event
of Default shall then exist or, after giving pro forma effect to such payment,
thereafter shall begin to exist, Core Molding may make Capital Distributions.

3.    Closing Deliveries. Concurrently with the execution of this Amendment, the
Borrowers shall:

(a)    cause each Guarantor of Payment to execute the attached Guarantor
Acknowledgment and Agreement; and

(b)    pay all legal fees and expenses of Agent in connection with this
Amendment and any other Loan Documents.

4.    Representations and Warranties. The Borrowers hereby represent and warrant
to Agent and the Lenders that (a) the Borrowers have the legal power and
authority to execute and deliver this Amendment; (b) the officers executing this
Amendment have been duly authorized to execute and deliver the same and bind the
Borrowers with respect to the provisions hereof; (c) the execution and delivery
hereof by the Borrowers and the performance and observance by the Borrowers of
the provisions hereof do not violate or conflict with the Organizational
Documents of the Borrowers or any law applicable to the Borrowers or result in a
breach of any provision of or constitute a default under any other agreement,
instrument or document binding upon or enforceable against the Borrowers; (d) no
Default or Event of Default exists, nor will any occur immediately after the
execution and delivery of this Amendment or by the performance or observance of
any provision hereof; (e) each of the representations and warranties contained
in the Loan Documents is true and correct in all material respects as of the
date hereof as if made on the date hereof, except to the extent that any such
representation or warranty expressly states that it relates to an earlier date
(in which case such representation or warranty is true and correct in all
material respects as of such earlier date); (f) the Borrowers are not aware of
any claim or offset against, or defense or counterclaim to, the Borrowers’
obligations or liabilities under the Credit Agreement or any other Related
Writing; and (g) this Amendment constitutes a valid and binding obligation of
the Borrowers in every respect, enforceable in accordance with its terms.

5.    Waiver and Release. The Borrowers, by signing below, hereby waive and
release Agent, and each of the Lenders, and their respective directors,
officers, employees, attorneys, affiliates and subsidiaries, from any and all
claims, offsets, defenses and counterclaims of which the Borrowers are aware,
such waiver and release being with full knowledge and understanding of the
circumstances and effect thereof and after having consulted legal counsel with
respect thereto.

6.    References to Credit Agreement and Ratification. Each reference to the
Credit Agreement that is made in the Credit Agreement or any other Related
Writing shall hereafter be construed as a reference to the Credit Agreement as
amended hereby. Except as otherwise specifically provided herein, all terms and
provisions of the Credit Agreement are confirmed and ratified and shall remain
in full force and effect and be unaffected hereby. This Amendment is a Loan
Document.

7.    Counterparts. This Amendment may be executed in any number of
counterparts, by different parties hereto in separate counterparts and by
facsimile or other electronic signature, each of which, when so executed and
delivered, shall be deemed to be an original and all of which taken together
shall constitute but one and the same agreement.

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8.    Headings. The headings, captions and arrangements used in this Amendment
are for convenience only and shall not affect the interpretation of this
Amendment.

9.    Severability. Any provision of this Amendment that shall be prohibited or
unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective
to the extent of such prohibition or unenforceability without invalidating the
remaining provisions hereof or affecting the validity or enforceability of such
provision in any other jurisdiction.

10.    Governing Law. The rights and obligations of all parties hereto shall be
governed by the laws of the State of Ohio, without regard to principles of
conflicts of laws.

[Remainder of page intentionally left blank.]

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JURY TRIAL WAIVER. THE BORROWERS, AGENT AND THE LENDERS, TO THE EXTENT PERMITTED
BY LAW, EACH HEREBY WAIVES ANY RIGHT TO HAVE A JURY PARTICIPATE IN RESOLVING ANY
DISPUTE, WHETHER SOUNDING IN CONTRACT, TORT OR OTHERWISE, AMONG THE BORROWERS,
AGENT AND THE LENDERS, OR ANY THEREOF, ARISING OUT OF, IN CONNECTION WITH,
RELATED TO, OR INCIDENTAL TO THE RELATIONSHIP ESTABLISHED AMONG THEM IN
CONNECTION WITH THIS AMENDMENT OR ANY NOTE OR OTHER INSTRUMENT, DOCUMENT OR
AGREEMENT EXECUTED OR DELIVERED IN CONNECTION HEREWITH OR THE TRANSACTIONS
RELATED THERETO. THIS WAIVER SHALL NOT IN ANY WAY AFFECT, WAIVE, LIMIT, AMEND OR
MODIFY THE ABILITY OF AGENT OR THE LENDERS TO PURSUE REMEDIES PURSUANT TO ANY
CONFESSION OF JUDGMENT OR COGNOVIT PROVISION CONTAINED IN ANY NOTE OR OTHER
INSTRUMENT, DOCUMENT OR AGREEMENT AMONG THE BORROWERS, AGENT AND THE LENDERS.

IN WITNESS WHEREOF, the parties have executed and delivered this Amendment in
Columbus, Ohio as of the date first set forth above.

 
CORE MOLDING TECHNOLOGIES, INC.

By: /s/ Kevin L. Barnett
      Kevin L. Barnett
      President and Chief Executive Officer

 
CORECOMPOSITES DE MEXICO, S. DE R.L. DE C.V.

By: /s/ Kevin L. Barnett
      Kevin L. Barnett
      Attorney-in-Fact
 
KEYBANK NATIONAL ASSOCIATION
    as Agent and as a Lender

By: /s/ Roger D. Campbell
      Roger D. Campbell
      Senior Vice President

Signature Page to
Twelfth Amendment Agreement

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GUARANTOR ACKNOWLEDGMENT AND AGREEMENT

The undersigned consent and agree to and acknowledge the terms of the foregoing
Twelfth Amendment Agreement dated as of August 4, 2017. The undersigned further
agree that the obligations of the undersigned pursuant to the Guaranty of
Payment executed by the undersigned are hereby ratified and shall remain in full
force and effect and be unaffected hereby.

The undersigned hereby waive and release Agent and the Lenders and their
respective directors, officers, employees, attorneys, affiliates and
subsidiaries from any and all claims, offsets, defenses and counterclaims of any
kind or nature, absolute and contingent, of which the undersigned are aware or
should be aware, such waiver and release being with full knowledge and
understanding of the circumstances and effect thereof and after having consulted
legal counsel with respect thereto.

JURY TRIAL WAIVER. THE UNDERSIGNED, TO THE EXTENT PERMITTED BY LAW, HEREBY WAIVE
ANY RIGHT TO HAVE A JURY PARTICIPATE IN RESOLVING ANY DISPUTE, WHETHER SOUNDING
IN CONTRACT, TORT OR OTHERWISE, AMONG BORROWERS, AGENT, THE LENDERS AND THE
UNDERSIGNED, OR ANY THEREOF, ARISING OUT OF, IN CONNECTION WITH, RELATED TO, OR
INCIDENTAL TO THE RELATIONSHIP ESTABLISHED AMONG THEM IN CONNECTION WITH THIS
AMENDMENT OR ANY NOTE OR OTHER INSTRUMENT, DOCUMENT OR AGREEMENT EXECUTED OR
DELIVERED IN CONNECTION HEREWITH OR THE TRANSACTIONS RELATED THERETO. THIS
WAIVER SHALL NOT IN ANY WAY AFFECT, WAIVE, LIMIT, AMEND OR MODIFY THE ABILITY OF
AGENT AND LENDERS TO PURSUE REMEDIES PURSUANT TO ANY CONFESSION OF JUDGMENT OR
COGNOVIT PROVISION CONTAINED IN ANY NOTE OR OTHER INSTRUMENT, DOCUMENT OR
AGREEMENT AMONG BORROWERS, AGENT, THE LENDERS AND THE UNDERSIGNED.

CORE COMPOSITES CINCINNATI, LLC

By: Core Molding Technologies, Inc.,
   Its sole member

By: /s/ Kevin L. Barnett
      Kevin L. Barnett
      President and Chief Executive
         Officer
CORE AUTOMOTIVE TECHNOLOGIES, LLC

By: Core Molding Technologies, Inc.,
   Its sole member

By: /s/ Kevin L. Barnett
      Kevin L. Barnett
      President and Chief Executive Officer

CORE COMPOSITES CORPORATION

By: /s/ Kevin L. Barnett    
Kevin L. Barnett
President and Chief Executive Officer

Signature Page to
Guarantor Acknowledgment and Agreement