Medical billers in California are responsible for managing the financial aspects of healthcare services, including processing and submitting insurance claims and billing patients for services. Some common job duties of medical billers in California include:

1. Reviewing patient medical records to ensure accuracy of billing information
2. Verifying patient insurance coverage and benefits
3. Preparing and submitting insurance claims to third-party payers, such as insurance companies and government programs
4. Resolving insurance claim rejections or denials and resubmitting claims as necessary
5. Posting payments and adjustments to patient accounts
6. Following up with patients on outstanding balances and past due accounts
7. Communicating with insurance companies, healthcare providers, and patients to resolve billing issues and disputes
8. Maintaining and updating patient billing records and files
9. Performing basic medical coding and billing tasks
10. Ensuring compliance with state and federal laws and regulations related to healthcare billing and reimbursement, such as HIPAA.

It's important to note that medical biller duties may vary depending on the specific healthcare setting and the type of healthcare provider they are working for. Additionally, medical billers in California must adhere to state and federal laws and regulations related to healthcare and patient privacy, such as HIPAA.