The California Supreme Court has ruled that patients no longer have to worry about getting billed for emergency treatment charges that their HMOs fail to pay. Health maintenance organizations and patient advocates hailed the decision as an important protection against price gouging, but doctors said it would encourage greedy HMOs to underpay them and that that could put emergency rooms in jeopardy. The decision also leaves open the question of what constitutes reasonable payment for emergency services. Regulations require HMOs to pay hospitals and physicians reasonable fees but do not set out specific amounts.