Starting Wednesday shoppers won't be able to get plastic bags at large Santa Barbara grocery stores or pharmacies.
Other options include paying 10 cents per paper bag, or bringing a reusable one.
Last October the Santa Barbara City Council adopted the single-use bag ordinance banning the plastic.
"This ordinance will reduce the plastic bags that are being used in Santa Barbara by 90 percent. So it's really about source reduction. The grocery stores are where most of the plastic bag traffic comes from. So by passing this law we are going to go from 47 million bags to fewer than 5 million bags," said Kathi King, of the Community Environmental Council.
The second phase of the ordinance will include smaller stores like mini-marts. Those shops have until November to comply.
"People do reuse them and there are a number of exemptions in the law that will provide people opportunities to continue to reuse bags, but the vast majority of single-use plastic bags that are made out of fossil fuel material that lasts forever are used once and thrown away," said King.
The exemptions to the ban include retail stores, take-out restaurants and plastic bags for produce.