Dr. Richard Pan and Ben Allen's announcement came on the day the state of California announced the number of measles cases had grown to 99. Many of those cases are tied to an outbreak at Disneyland in mid-December.
The comparatively large number of cases in California this year and in the United States the past year have sparked debate over whether unvaccinated children should be allowed in public school.
California allows exemptions from vaccinations for medical reasons and "personal beliefs," and parents have been using them.
"As a pediatrician I have personally witnessed children suffering lifelong injury or death from vaccine-preventable infection," said Pan, who also wrote the California law that requires people who want to file a personal exemption to consult a doctor.
He said the proposed bill would focus on vaccinations required to attend school.
"We're not reaching sufficient immunization rates and we want to reach the rates necessary to protect the public from those diseases," he told reporters in Sacramento.
CNN affiliate KTLA
reported several members of the California State Assembly will be co-authors of the bill.
Measles starts with a fever, runny nose, cough, red eyes and sore throat. For most people, it doesn't get much worse than that -- and yet one out of every 20 children with measles also contract pneumonia, and one or two out of every 1,000 children with the disease die from it, according to the Centers for Disease Control and Prevention.
While once widespread in the United States, cases dropped significantly because of vaccines. In 2000, health authorities declared that measles had been eliminated in the United States, which meant it was no longer native to the United States but continued to be brought in by international travelers.
On Monday, a Southern California day care shut down because an infant there -- who is too young to be vaccinated -- contracted measles.
The Samohi Infant Toddler Center inside Santa Monica High School, a facility for 24 children of students and staff members, closed Monday after it was learned that a baby under 12 months old being cared for there had measles. It's not clear when, where or how the child got the disease.