The highest mountain in the world will be closed to climbers until at least 30 April.
Mount Everest has shut down for the rest of the expedition season because of the coronavirus outbreak.
Nepal's government announced that it would cancel all climbing permits from 14 March until 30 April.
China had already cancelled expeditions from the northern, Chinese-controlled, side of the mountain.
According to the Kathmandu Post, the Nepal earns $4m (£3.1m) by issuing Everest climbing permits every year, aside from wider tourism revenue.
"We have decided to halt all tourist visas until 30 April," said Narayan Prasad Bidari, Secretary of the Prime Minister's Office.
"As of now, all issued permits and permits yet to be issued for the 2020 Everest season will be cancelled."
It also advised foreigners who were unable to avoid coming to Nepal from 14 March to stay in quarantine for 14 days.
Most climbers come from the US, India, China, UK, Japan, and South Korea - and are a major source of revenue for the Nepalese government.
Typically, anyone who wants to climb Everest needs to pay the government $11,000 (£8,700), though there were talks by the government to raise this figure.
And that's not including fees that are typically paid to the travel companies, which can also run up tens of thousands.
Local sherpas who work as mountain guides will also be affected.
"My nine Chinese clients and a Japanese client have cancelled already. Many trekking teams are not coming, which is a big loss for sherpas like us who make most of our money during this time," Lakpa Sherpa, managing director of Pioneer Adventure, told BBC Nepali.
There is currently one confirmed virus case in Nepal, but the country borders India which has more than 70 cases.
Nepal's government has asked its citizens to avoid mass gatherings including marriages and public functions.
More than 125,000 people have been diagnosed with Covid-19 in 118 countries around the world, according to the World Health Organization. The total number of deaths is more than 4,600. BBC