The internet mogul's battle has dragged on for more than six years, starting in January 2012 when police acting on an FBI request raided his Auckland mansion.
The 44-year-old German is accused of industrial-scale online piracy via his Megaupload empire, which US authorities shut down.
If sent to the United States he will face charges of racketeering, fraud and money laundering carrying jail terms of up to 20 years.
Dotcom and his three co-accused - Finn Batato, Mathias Ortmann and Bram van der Kolk - maintain their innocence and will challenge the legitimacy of their arrests at the Court of Appeal in Wellington.
Megaupload was an early example of cloud computing. The FBI says it netted over US$175 million (HK$1.37 billion) and cost copyright owners US$500 million-plus.