McEachern was at Seix Investment Advisers for 14 years, latterly as president and head of the company’s high yield division.
He will continue to be based in New York and will work across Muzinich’s investment portfolios.
McEachern said: "The company’s commitment to deep fundamental credit research and its risk-sensitive approach is completely in-line with my own investment philosophy."
Muzinich & Co specialises in corporate credit and credit-oriented strategies and has approximately $14bn AUM.
In the UK it is regulated by the FSA, while its funds, including Short Duration High Yield, are regulated by the Irish Central Bank.
