Anthem does this in waves so 'not to stir the pot' ,if you will. Too many layoffs at once in a particular state,in a certain time frame, a company is required to report to the labor board - Anthem is laying low. They have this all figured out . For CA: https://www.nolo.com/legal-encyclopedia/layoff-protections-california-employees.html
Exactly what @ZpsTrW6-nww said.
Rapid Response team or the workers themselves can file a trade petition with the United States Department of Labor. For more information on the Trade Act Program and its benefits, contact your state's Rapid Response team.
https://www.doleta.gov/tradeact/docs/program_brochure2014.pdf
https://www.doleta.gov/tradeact/benefits/
Benefits and Services: If a worker is a member of a worker group certified by DOL, that worker may be eligible to receive the following benefits and services at a local American Job Center:
Employment and Case Management Services: Skills assessments, individual employment plans, career counseling, supportive services, and information on training, labor markets, and more (through TAA or other American Job Center programs).
Training: Classroom training, on the-job training, customized training designed to meet the needs of a specific employer or group of employers, apprenticeship programs, and more.
Trade Readjustment Allowances (TRA): Income support available in the form of weekly cash payments to workers who are enrolled in a full-time training course and have exhausted their unemployment insurance.
Job Search Allowance: Reimbursement for costs of seeking employment outside of the worker’s commuting area.
Relocation Allowance: Reimbursement for relocation costs for employment outside of the worker’s commuting area.
Alternative Trade Adjustment Assistance (ATAA) and Reemployment Trade Adjustment Assistance (RTAA): A wage subsidy for up to two years that is available to reemployed older workers and covers a portion of the difference between a worker’s new wage and their old wage (up to a specified maximum amount).
If you know your company is planning layoffs and the workers not been told that Rapid Response services will be available to you, or your company laid you off without notice, please contact your state's Rapid Response team.
https://www.doleta.gov/layoff/workers/
"The EDD has established Rapid Response Teams to assist employers and workers during a mass layoff or plant closing. These teams, facilitated through America’s Job Center of California (AJCC) locations, are a cooperative effort between the Local Area and the EDD. This team disseminates information about the adult and dislocated worker services available under Title I of the Workforce Innovation and Opportunity Act and through the AJCC, and Unemployment Insurance programs.
If the dislocation is the result of foreign competition or foreign relocation, the dislocated worker may be eligible for assistance, income support, job search assistance/relocation, and/or training under the Trade Adjustment Assistance (TAA) Program."
This is not new. Many companies do this. "Stay under the required reported number", skirted, as at least out this way, slightly north of Boston major metro, it requires 60 days notice ... to employees - in which case they stop working and start looking for a new job - and coworkers complain, "Who's going to [be doing their work]?".
Anthem is trying to get away with WARN ACT. You can read more here,
https://www.edd.ca.gov/Jobs_and_Training/Layoff_Services_WARN.htm