According to the company, the new funding values ZocDoc at $1.8 billion, making it part of an ever-growing, unofficial group known as the 'Unicorn Club' - a collection of more than 120 private tech companies valued at $1 billion or more.

ZocDoc, which was founded in 2007, is now one of New York's biggest startups. Last year, reports said the company was seeking to raise $152 million at a $1.6 billion valuation, which would have added to the $97.9 million war chest it had previously amassed over the years.

The only two New York City startups more valuable than ZocDoc are Blue Apron, a $2 billion food delivery startup, and WeWork, a $10 billion company that rents out office space, according to Dow Jones VentureWire.

ZocDoc has made headlines for less positive news recently, too. A former ZocDoc employee said in the fall that she would be filing a lawsuit against the company, alleging sexism and a brogrammer culture in the company's NYC headquarters. She didn't end up taking ZocDoc to court, but more than half a dozen former and current ZocDoc employees since told Business Insider that ZocDoc was being run like a 'frat house,' where drug use and sexism were big problems on the company's sales floor.

ZocDoc has more than 600 employees between its New York, Arizona, and India offices.

Investors in the new round of funding, which closed last month, include Baillie Gifford, Atomico, and Founders Fund, which was an earlier investor in the startup. Other institutional investors include DST Global, Goldman Sachs, Khosla Ventures, Founders Fund, and SV Angel.