This comes after the federal government approved the state's application for funding for the program after a $600 weekly payment expired last month.
When Congress failed to reach a deal, President Donald Trump issued an executive order extending benefits by $300 per week for up to three weeks. The $900 payment covers three weeks of benefits retroactive to the week ending Aug. 1.
California unemployment: State gets federal funds to pay additional $300 per week in benefits
The state Employment Development Department said it is starting to send the supplemental payment Monday to 3.1 million Californians who have been receiving at least $100 in weekly unemployment benefits from the state and previously certified that they were unemployed due to COVID-19, according to The Los Angeles Times.
However, many will not receive the assistance right away.
The EDD said it will take "a couple of weeks" to send out all of the benefits.
The Times reports an additional 1.2 million claimants still need to certify eligibility that their joblessness is related to the pandemic, and those people will be notified by the EDD starting Sept. 15.
Close to 200,000 unemployed residents will not receive the extra $900 benefit at all because they have been receiving less than $100 in state benefits, the threshold set by the federal government for participation, according to The Times.
Unemployment claims rose for a second week in California following a long stretch of improvement.
An additional 236,000 people applied for jobless benefits the last week of August, bringing the total since the onset of the outbreak to more than 8 million -- or just over 40% of the workforce.