Union Square Ventures and existing investor FirstMark Capital led the round, which brings Justworks' total funding to $143 million. All other existing investors in Justworks, including Bain Capital Ventures, Index Ventures, Redpoint Ventures, Spark Capital, and Thrive Capital, also participated in the Series E.

Founded in 2012, Justworks makes it easier to start, run and grow a business. It pioneered the first truly technology-enabled version of the Professional Employer Organization (PEO) model, creating a more cost-effective way to bring the advantages of using a PEO to America's highest-potential businesses: small and medium-sized companies with under 200 employees. Today, Justworks aggregates the over 86,000 employees on its platform to provide economies of scale that democratize access to big-company benefits, health and wellness providers, payroll, HR tools and compliance support for thousands of the most promising entrepreneurs and their teams across all 50 U.S. states.

The PEO model has been around for decades, allowing legacy players to grow into multibillion-dollar companies, in part, due to its solid customer value proposition and favorable business dynamics. The need for handling critical tasks related to payroll, employment-related taxes, HR and health insurance continues to grow-taking today's entrepreneurs away from what really matters: building their business and focusing on their customers and team.

"Justworks reinvented the PEO model by delivering an experience people love," said Isaac Oates, founder and CEO of Justworks. "The modern workforce expects simplicity and seamlessness in the tools they use and technology that empowers them to do things by themselves. By combining SaaS flexibility, transparent pricing and off-the-shelf functionality with 24/7 expert support for customers and their teams, Justworks provides an unmatched PEO offering for the modern business. This new investment will help us to strengthen these advantages and double down on our growth as the expectations of an increasingly millennial workforce continue to drive ever more B2B buying decisions."

"Justworks has raised the bar on what people can expect from a PEO," said Fred Wilson, partner at Union Square Ventures. "Their software is elegant, intuitive and easy-to-use, and Justworks' technology and operating model allows them to serve small and medium-sized businesses better than anyone else in the market. This has led to rapid growth and, more importantly, the creation of a category-defining offering that drives levels of customer retention and satisfaction that are simply unheard of in the HR services space. We are pleased to welcome Justworks to our portfolio and to be their partner in creating a fundamentally better PEO product for the modern workforce."

"Working with Isaac and his team as a Board member for two years now, I have seen how the Justworks team rallies around its mission to level the playing field for entrepreneurs and help teams achieve their potential," said Beth Ferreira, partner at FirstMark Capital. "In that time, Justworks has more than doubled in size and realized significant operational sophistication and efficiency at scale. We are strong believers in the company as they continue to push forward to revolutionize the HR industry."

"We are driven to help entrepreneurs and businesses grow with confidence," said Oates. "Our success depends on making that a more accessible option for all, and our own ability to stay true to the things that have made Justworks special from the beginning-obsessing over our customers, delivering experiences that people love and an aspiration to create a company for the ages. We are thrilled to be starting a new relationship with Union Square Ventures and are proud of our continuing strong relationships with current partners."

About Justworks:
Justworks makes it easier to start, run and grow a business. Founded in 2012, Justworks, the nation's fastest-growing HR technology company, is a modern support system for work and life. With Justworks, entrepreneurs and their teams get access to big-company benefits, automated payroll, compliance support, and HR tools-all in one place. By combining the power of a Professional Employer Organization (PEO) with expert 24/7 customer service and a simple and intuitive platform, Justworks gives teams of all sizes the confidence to work fearlessly. To learn more about Justworks you can visit https://justworks.com, follow them on Twitter @JustworksHR and on Instagram @Justworks_HR.