Sec Form 4 Filing - ASP MD Investco LP @ Metaldyne Performance Group Inc. - 2015-09-01

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person ASP MD Investco LP 2. Issuer Name and Ticker or Trading Symbol Metaldyne Performance Group Inc. [ MPG] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O AMERICAN SECURITIES LLC, 299 PARK AVENUE, 34TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 09/01/2015 (Street) NEW YORK, NY10171 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock, par value $0.001 per share 51,365,358 D ( 1 ) ( 2 ) Common Stock, par value $0.001 per share 09/01/2015 A 2,645 ( 3 ) A $ 20.02 2,645 ( 4 ) D ( 4 ) Common Stock, par value $0.001 per share 09/01/2015 A 2,645 ( 3 ) A $ 20.02 2,645 ( 5 ) D ( 5 ) Common Stock, par value $0.001 per share 09/01/2015 A 2,645 ( 3 ) A $ 20.02 2,645 ( 6 ) D ( 6 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other ASP MD Investco LP C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK, NY10171 X American Securities Partners VI, L.P. C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK, NY10171 X American Securities Partners VI(B), L.P. C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK, NY10171 X American Securities Partners VI(C), L.P. C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK, NY10171 X American Securities Partners VI(D), L.P. C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK, NY10171 X American Securities Associates VI, LLC C/O AMERICAN SECURITIES LLC 299 PARK AVENUE, 34TH FLOOR NEW YORK, NY10171 X AMERICAN SECURITIES LLC 299 PARK AVENUE 34TH FLOOR NEW YORK, NY10171 X Penn Kevin S. C/O METALDYNE PERFORMANCE GROUP INC. 47659 HALYARD DRIVE PLYMOUTH, MI48170 X Easton Loren S. C/O METALDYNE PERFORMANCE GROUP INC. 47659 HALYARD DRIVE PLYMOUTH, MI48170 X Fisch Michael G. C/O METALDYNE PERFORMANCE GROUP INC. 47659 HALYARD DRIVE PLYMOUTH, MI48170 X Signatures ASP MD Investco LP, By: ASP Manager Corp., its general partner, /s/ Michael G. Fisch, as President 09/03/2015 Signature of Reporting Person Date American Securities Partners VI, L.P., By: American Securities Associates VI, LLC, its general partner, /s/ Michael G. Fisch, as Managing Member 09/03/2015 Signature of Reporting Person Date American Securities Partners VI(B), L.P., By: American Securities Associates VI, LLC, its general partner, /s/ Michael G. Fisch, as Managing Member 09/03/2015 Signature of Reporting Person Date American Securities Partners VI(C), L.P., By: American Securities Associates VI, LLC, its general partner, /s/ Michael G. Fisch, as Managing Member 09/03/2015 Signature of Reporting Person Date American Securities Partners VI(D), L.P., By: American Securities Associates VI, LLC, its general partner, /s/ Michael G. Fisch, as Managing Member 09/03/2015 Signature of Reporting Person Date American Securities Associates VI, LLC, /s/ Michael G. Fisch, as Managing Member 09/03/2015 Signature of Reporting Person Date American Securities LLC, /s/ Michael G. Fisch, as President and Chief Executive Officer 09/03/2015 Signature of Reporting Person Date /s/ Kevin Penn 09/03/2015 Signature of Reporting Person Date /s/ Loren Easton 09/03/2015 Signature of Reporting Person Date /s/ Michael G. Fisch 09/03/2015 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The shares are directly owned by ASP MD Investco LP ("Investco") and may also be deemed to be indirectly beneficially owned by: (i) American Securities Partners VI, L.P., American Securities Partners VI(B), L.P., American Securities Partners VI(C), L.P. and American Securities Partners VI(D), L.P. (each, a "Sponsor"), the owners of partnership interests in Investco; and (ii) American Securities Associates VI, LLC, the general partner of each Sponsor. American Securities LLC ("ASL") provides investment advisory services to each Sponsor. ( 2 )Each Reporting Person disclaims beneficial ownership of the reported securities except to the extent of such Reporting Person's pecuniary interest therein, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose. ( 3 )Restricted Stock vests in three annual installments beginning on September 1, 2016. ( 4 )Kevin Penn is a managing director of ASL (and a director of Issuer). Pursuant to an arrangement between Mr. Penn and ASL, all director fees received by him from the Issuer are paid over to or held for the benefit of ASL. ( 5 )Loren Easton is a managing director of ASL (and a director of the Issuer). Pursuant to an arrangement between Mr. Easton and ASL, all director fees received by him from the Issuer are paid over to or held for the benefit of ASL. ( 6 )Michael G. Fisch is President and Chief Executive Officer of ASL (and a director of the Issuer). Pursuant to an arrangement between Mr. Fisch and ASL, all director fees received by him from the Issuer are paid over to or held for the benefit of ASL.

Remarks: Exhibit 99.1 Joint Filer Information, incorporated herein by reference

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

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