The Fantasy 5 ticket was purchased at San Francisco Gifts and News at 350 California St. on Oct. 29. The winning numbers are 9, 22, 29, 35 and 36.
Lottery spokeswoman Monique Blue said today the ticket will expire at close of the business day Monday.
"It's very rare that one of $100,000 doesn't go claimed," blue said, adding that lottery officials are hopeful the winner come forward in time.
However, if the lottery ticket goes unclaimed, the money will go to education in the state, Blue said. Lottery winners have 180 days to claim their prizes.