Phelan passed away in 1955, leaving the company to his wife, Sally, and sons, Joseph, Richard, and Samuel.

[citation needed] The National Institutes of Health contracted Taconic in 1970 to provide them with Sprague Dawley rats and BDF1 mice.

[citation needed] In 1975, Taconic began offering the SHR hypertensive rat and the control strain, Winstar Kyoto (WKY).

[citation needed] In the 1980s, Taconic developed the first Isolated Barrier Unit system, a method of housing rodents in a pathogen-free environment.

[citation needed] In 1994, Taconic was contracted with the National Institute for Allergy and Infectious Disease to maintain a repository of inbred, congenic, and transgenic mice.

[11] In April of that same year, the company launched TruBIOME, a platform that “enables researchers to develop models with customized microbiota profiles.”[12] In 2022, Taconic was acquired by Avista Capital Partners[13] In January 2023, the company announced they had, in partnership with Cure Rare Disease, developed a “knock-in mouse model,” which carries a mutation known to cause ADSSL1- gene-related myopathy.