The legislation also mandated two weeks of paid leave to care for a relative who was quarantining after contracting Covid-19, and 10 weeks of paid family leave to look after a child whose school or daycare was closed because of the pandemic.
The requirement was not universal, as businesses with more than 500 employees were exempt from providing the paid leave, while companies with fewer than 50 workers were able to apply for an exemption.
However, as part of the first coronavirus relief package since spring, which was agreed by Congress on Sunday, the paid leave mandate was not extended, according to Buzzfeed News.
Both Republican and Democratic Congressional aides told Buzzfeed that the extension of paid leave was left out of the bill as a concession to Mr McConnell, who had been pushing for it not to be included.
Despite the end of the mandate, the bill does extend a refundable tax credit that subsidises the cost of paying sick leave until the end of March 2021.
However, making use of this subsidy is optional for businesses, meaning that US employees will no longer be automatically entitled to paid sick leave after contracting Covid-19.
Congress passed the long-awaited relief bill on Monday evening, which is expected to be signed into law by President Donald Trump on Tuesday.
A Senate Republican aide told Buzzfeed that House Speaker Nancy Pelosi held up an agreement on the relief deal on Saturday night because it did not include the mandate.
The aide said that she continued to try and get it added over the next day, but in the end settled for the tax credits.
A recent Health Affairs study found that paid sick leave decreased the spread of Covid-19 in the US, and projected that its extension would cost between $8bn (£5.9bn) to $13bn (£9.6bn). That figure is around 1 per cent of the $900bn (£669.9bn) deal passed on Monday.
Democratic lawmakers will continue pushing to get paid sick leave mandated, and are hopeful to pass another Coronavirus relief deal after President-elect Joe Biden takes office on 20 January.
Senator Patty Murray, the Democrat lead on the Senate Health Committee, told Buzzfeed: “Businesses can use these tax credits to provide paid sick days to their workers, and I hope they do — but it’s not nearly enough.”
The senator added: “This crisis has made it clearer than ever why paid leave for every worker is so important to families, communities, and our economy as a whole.”
According to Johns Hopkins University, there are now more than 18 million people who have tested positive for the coronavirus in the US. The death toll has reached 319,466.
The Independent has contacted both Mr McConnell and Ms Pelosi’s office for comment.