In her California Healthcare Foundation report, Katherine Wilson does a nice job describing the health insurance market in California. A little over health of individuals received health care from their employer or themselves (56%), a quarter of individuals receive health insurance through public programs, and 19% of Californians are uninsured (see chart).
The private health insurance market cannot be portrayed as a monopoly nor one that is truly competitive in the neoclassical sense. A handful of insurance carriers dominate the market. Kaiser, Blue Cross, HealthNet, Blue Shield, Pacificare, and Aetna control 77% of the market (see chart).
Of the premiums insurers receive, the percentage of revenues going to medical care varies widely. Kaiser spends 93% of revenue on medical expenses, but Blue Shield and Pacificare’s traditional insurance plans spend only 70% of revenues on medical expenses. Administrative expense ratios are also much lower for Kaiser (3.6%) than for providers such as Blue Shield’s tradiational Insurance plan (22.7%). More details about load factors are available here (see chart).
The full CHCF report can be viewed here.