Washington (CNN) California has become the first state to extend health care coverage to some undocumented young adults through its Medicaid program.

Democratic Gov. Gavin Newsom on Tuesday signed SB-104 , which extends health care benefits to individuals 19 to 25 years of age, regardless of their immigration status.

The bill was introduced earlier this year and was initially proposed by Newsom as part of a larger health care package. It is expected to cover some 90,000 low-income residents between the ages of 19 and 25 and to cost the state $98 million in its initial year. The coverage would take effect in 2020, according to the legislation.

The federal Medicaid program prohibits payment to a state for medical assistance furnished to an undocumented immigrant who is not lawfully admitted for permanent residence or otherwise permanently residing in the United States under color of law, according to the bill.

Under the new law, California's Medi-Cal coverage would be extended to those between 19 to 25 years of age, whether they have "satisfactory immigration status" or not. California already offers a health care plan for those younger than 19, regardless of their immigration status.

Read More