The bill by Assemblywoman Toni Atkins, D-San Diego, would let those professionals perform what are known as aspiration abortions during the first trimester. The method involves inserting a tube and using suction to terminate a pregnancy.
Supporters, including Planned Parenthood Affiliates of California, said expanding the ranks of those who can perform early abortions would provide better health care for women.
"Timely access to reproductive health services is critical to women's health," Atkins said in a statement Wednesday. "AB154 will ensure that no woman has to travel excessively long distances or wait for long periods in order to obtain an early abortion."
Brown announced his approval of the bill along with several others related to women's health care.
His signature on AB154, which goes into effect Jan. 1, came as other states have been restricting access to abortions.
Republican lawmakers who opposed the legislation argued that allowing non-doctors to perform aspiration abortions would increase risks to patients. They expressed concerns that those medical professional would lack training and assistance from experienced physicians.
"It's truly disheartening and disingenuous that Governor Brown and legislative Democrats created a law to lower the standard of care for the women under the guise of creating 'access,'" Assemblyman Brian Jones, R-Santee, said in a statement Wednesday.
The California Catholic Conference, which represents bishops throughout the state, said the law will create a two-tiered health system, separating those who can afford physicians and hospitals for abortion procedures from those who cannot.
"The often repeated mantra of those supporting (abortion) rights is that abortions ought to be safe, legal and rare," the conference's president, the Rev. Gerald Wilkerson of Los Angeles, said in a statement. "With this change in California's law, abortions are merely legal — no longer safe and... rare."
He also reiterated the church's opposition to abortion and any laws that seek to expand it.
The bill signed by Brown, a former Jesuit seminary student, requires non-doctors seeking to perform abortions to receive special training and follow standard procedures.
Under a state pilot program created in 2007, 8,000 aspiration abortions already have been provided by non-doctors in California. Data from the University of California, San Francisco program showed doctors and non-doctors performing the procedures with complication rates below 2 percent.
The researchers wrote in a January article in the American Journal of Public Health that the findings support broadening who can perform early aspiration abortions. They added that such a change would likely allow for abortions to be performed sooner, "significantly decreasing the overall risk of complications, which increases with gestational age."
Tracy Weitz, an associate professor at UCSF and lead author on the study, said in an interview that the lack of access to abortion services is most common in places that generally have fewer health care services, such as rural areas.
Access issues also can be found in urban areas such as Los Angeles County, where communities can be underserved because it is difficult to get to a provider located in another part of the county, she said.
Among the other bills signed Wednesday by Brown:
— AB219 from Assemblyman Henry Perea, D-Fresno, requires health insurers to cap the cost to patients for oral anticancer medications at $200 for a 30-day supply of pills. The monthly cost of chemotherapy pills for patients who have insurance can reach $4,000, according to Perea.
— AB980 from Assemblyman Richard Pan, D-Sacramento, brings construction standards for clinics that perform abortions in line with all other primary care clinics.
— AB1308 from Assemblywoman Susan Bonilla, D-Concord, allows licensed midwives to handle normal childbirth cases without the supervision of a physician. Midwives will be required to refer a pregnant woman to a doctor if the patient develops potentially complicating conditions.