Medicaid (MediCal in California) is a joint federal and state government insurance program designed to help low-income individuals pay for some or all of the bills for long term care services at home or in a skilled nursing facility.
The rules and coverage for these programs is based on federal requirements. Never the less, states have the option to decide what services they provide and how to qualify for them, so rules and services vary from state to state.
The formula to get Medicaid or MediCal benefits is complicated, but you must have limited income and savings to qualify. The amount of income varies by state and is set at the poverty level. As a result, Medicaid is not an option for most individuals with significant retirement income, savings, investments, or assets.