Goldman Sachs & Co. LLC

200 West Street

New York, New York 10282

J.P. Morgan Securities LLC

383 Madison Avenue

New York, New York 10179

Securities and Exchange Commission

Division of Corporation Finance

100 F Street, N.E.

Washington, D.C. 20549-7010

Attn: Erin Purnell

Registration Statement on Form S-1

Registration File No. 333-248969

Ladies and Gentlemen:

In accordance with Rule 461 under the Securities Act of 1933, as amended (the “Act”), we, as representatives of the several underwriters, hereby join in the request of ATI Intermediate Holdings, LLC (the “Company”) for acceleration of the effective date of the above-named Registration Statement on Form S-1, as amended, so that it becomes effective at 2:30 PM, Eastern Time, on October 14, 2020 or as soon thereafter as practicable, or at such other time as the Company or its outside counsel, Kirkland & Ellis LLP, may orally request via telephone call that such Registration Statement be declared effective.

Pursuant to Rule 460 under the Act, we, as representatives of the several underwriters, wish to advise you that approximately 4,300 copies of the Preliminary Prospectus included in the above-named Registration Statement, as amended, were distributed during the period from October 7, 2020 through the date hereof, to prospective underwriters, institutions, dealers and others.

We, the undersigned, as representatives of the several underwriters, will comply with the requirements of Rule 15c2-8 under the Securities Exchange Act of 1934, as amended.

[Signature Page to Underwriters’ Acceleration Request]