Health care firms spent more than $35 million on lobbying in California in 2011.
Kaiser spent $3.5 million lobbying in California last year.
The insurer doesn't say what measures it was concerned about.
"Whether it's more regulation of the hospitals, or lowering the cost of health-insurance premiums, Kaiser has an interest in keeping regulators away from their business," Court said.
The California Hospital Association was the state's second-biggest health care lobbyist last year.
Overall statewide, health care groups spent more than any other industry on lobbying in 2011.