CERTIFICATION FILED AS EXHIBIT 13 (B) TO FORM N-CSR

Name of Issuer: AMG FUNDS III –AMG MANAGERS CADENCE MID CAP FUND AND AMG MANAGERS CADENCE EMERGING COMPANIES FUND

In connection with the Report on Form N-CSR of the above-named issuer that is accompanied by this certification, the undersigned hereby certifies, to his knowledge, that:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the issuer.

Dated: February 1, 2018	/s/ Jeffrey T. Cerutti
	Jeffrey T. Cerutti
	Principal Executive Officer

CERTIFICATION FILED AS EXHIBIT 13 (B) TO FORM N-CSR

Name of Issuer: AMG FUNDS III –AMG MANAGERS CADENCE MID CAP FUND AND AMG MANAGERS CADENCE EMERGING COMPANIES FUND

In connection with the Report on Form N-CSR of the above-named issuer that is accompanied by this certification, the undersigned hereby certifies, to his knowledge, that:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the issuer.

Dated: February 1, 2018	/s/ Thomas Disbrow
	Thomas Disbrow
	Principal Financial Officer