Mallinckrodt Enterprises LLC, Hazelwood, Mo., hired Fidelity Investments as record keeper of its 401(k) plan, according to a brochure posted on the plan's website.
Fidelity replaced Transamerica Retirement Solutions effective Nov. 1. The reason for the change was not given.
The investment option lineup remained the same, except for the addition of a money market fund managed by Fidelity that replaces a similar fund managed by Vanguard Group.
The plan has a total of nine investment options and a target-date fund lineup managed by BlackRock.
As of Dec. 31, 2016, the Mallinckrodt Pharmaceuticals Retirement Savings and Investment Plan had $657 million in assets, according to the company's most recent Form 5500 filing.
Rhonda Sciarra, company spokeswoman, declined to comment.