As of the end of 1998, the company generated more than $320 million in sales per year and employed about 2,800 people in the United States and more than 4,500 in Europe.

[4][7] In 2005, the company paid $185 million to acquire InChord Communications, a healthcare marketing agency based in Westerville, Ohio.

[12] In 2010, the company, which at the time was traded on NASDAQ as VTIV, went private with the acquisition by Thomas H. Lee Partners in a deal estimated at $1.1 billion.

[13][14] In January 2018, eight months after INC Research announced plans to acquire it,[15] the firm assumed a new name, Syneos Health, and stock symbol, Nasdaq: SYNH.

[18] In April 2022, Michelle Keefe, who previously worked for two decades at the pharmaceutical Pfizer, was appointed CEO of Syneos Health to succeed Alistair Macdonald who had led the company since 2017.

[19][20] In March 2023, the company signed a multi-year deal to collaborate with Microsoft Research in development of a platform to leverage machine learning for the optimization of clinical trials.