Supporters of US Senator Bernie Sanders pose with a snow man before a rally to kick off his 2020 US presidential campaign, in the Brooklyn borough of New York City, on March 2, 2019 in.
CNN  — 

Sen. Bernie Sanders has raised $18.2 million from 525,000 individual donors since entering the Democratic presidential primary in February, his campaign said Tuesday.

One in five of those donors gave to Sanders for the first time, campaign manager Faiz Shakir told reporters. That total, amassed over 41 days culminating with Sunday’s quarterly deadline, means Sanders enters the second phase of the campaign with $28 million in cash-on-hand.

Sanders’ first quarter haul exceeded that of California Sen. Kamala Harris, who announced about a month earlier; she raised $12 million, her campaign said on Monday night. Pete Buttigieg, the mayor of South Bend, Indiana, took in more than $7 million, according to his team.

Sanders’ average donation clocked in at around $20.

The Sanders fundraising numbers confirm his status as a frontrunner in the increasingly crowded race for the Democratic nomination. Former US Rep. Beto O’Rourke has not yet released his figures for the quarter. O’Rourke raised $6.1 million during his first day as a candidate, slightly more than Sanders’ $5.9 million. Sanders took in more than half his $18.2 million during the first week of his campaign.

The campaign fell short of its goal of collecting 1 million contributions by the deadline, and instead brought in about 900,000 contributions from its donors. Senior adviser Jeff Weaver said the campaign still has outpaced its 2016 performance, when it took Sanders 146 days to hit the 900,000-contributions mark.

Sanders’ campaign said the makeup of their donors puts the Vermont independent in a good position to continue raking in contributions as the campaign heats up and they begin to set down stakes in new states. Shakir reported that 88% of the total came from donations of $200 or less and that 99.5% of donations were for $100 or less. The majority of donors were young, he said, and that the occupation most likely to give were teachers.

“With respect to how you finance campaigns, I believe (the source of donations) tells you a little bit about how much liberty you’re going to have to govern,” Shakir told reporters. “Bernie Sanders is a free man, not captured by industry, and is instead going to fight for all the people.”

Candidates do not have to disclose full details of their fundraising and spending to the Federal Election Commission until April 15. But contenders with good news to share often release selected numbers to tout their fundraising prowess or grassroots support.

Of the three candidates who have announced first-quarter totals so far, Sanders also has the largest number of donors. Buttigieg said Monday that he had drawn 158,550 donors to his exploratory committee. Harris received contributions from 138,000 contributors, a campaign source told CNN on Tuesday.

Sanders is the only one to disclose how much cash he has remaining in the bank. Money leftover from his early campaigns have helped him amass the large reserves.

The campaign also said Tuesday that it had roughly 100 people currently on staff and Weaver touted plans to begin hiring in “the all-important” state of California, which moved up its primary date for 2020.

“While we had to in 2016 make choices about where we could compete, I’m certain that in this race, some of our opponents will also have to make similar difficult choices,” Weaver said. “This campaign will have the resources and the volunteer grassroots strength to compete in every single state in the primary process.”

CNN’s Kyung Lah