Confidential employee information, emails and details of some stars' earnings were revealed in the embarrassing data breach.
It is the first time the Justice Department has brought criminal charges against a hacker said to be from North Korea.
Britain's National Cyber Crime Unit said it had obtained critical evidence which was able to link the NHS attack to others already being investigated in the US.
USA officials long believed the attack was retribution for The Interview, a comedy starring Seth Rogen and James Franco about a plot to assassinate North Korea's leader.
"This was one of the most complex and longest cyberinvestigations the department has taken", said John Demers, assistant attorney general for national security.
The suspected hacker, Pak Jin Hyok, acted on behalf of the Hermit Kingdom's Reconnaissance General Bureau, the military intelligence agency that controls most of the country's cyber capabilities, The Washington Post reported, citing USA officials. It also led to the cancelled release of the film The Interview. "If they don't, this president will act on behalf of the United States".
A North Korean man has been identified as part of a group that hacked the NHS, as well as allegedly being responsible for hacks on Sony Pictures and the theft of $81m (£62m) from a bank.
Officials state in the complaint that Park was working for a front company named the Korean Expo Joint Venture, which worked on behalf of North Korean intelligence and was charged with generating revenue for the military branch.
In one attack, an email sent to a victim from Facebook alerting them to the fact that their account had been accessed from a different IP address was grabbed by the hackers and then resent with the hyperlink within the email changed from Facebook's website to a domain that they controlled.
The entertainment groups were targeted because of movies that depict the North Korean government unflatteringly.
The DOJ has charged hackers in China, Iran and Russian Federation aiming to dissuade foreign powers from accommodating those who would attack US corporations. There has been no communication between the USA and North Korean government about a possible extradition, the official said.
"We will not allow North Korea to undermine global cybersecurity to advance its interests and generate illicit revenues in violation of our sanctions", Treasury Secretary Steven Mnuchin said in a statement.
In 2014, for instance, the Obama administration charged five Chinese military hackers with a series of digital break-ins at American companies, and a year ago, the Justice Department charged Russian hackers with an intrusion at Yahoo Inc.