New York state doctors and hospitals serving patients enrolled in most health plans other than health maintenance organization plans can bill patients for amounts not paid by the plans.

The New York State Insurance Department Office of General Counsel presents that conclusion in OGC Op. No. 09-10-07, an opinion issued April 13 and posted to the Web earlier this week.

Officials in the office consider several questions about “balance billing” — the practice of health care providers billing patients for amounts not covered by health insurance.

One question concerns in-network providers treating patients with HMO coverage.

The other questions concern providers treating patients with coverage provided by an insurer that is not an HMO; patients with coverage from a self-funded employer plan; patients with coverage from a self-funded employer plan that offers an insured limited-benefit plan; or patients with high-deductible coverage.

“When health care service is provided by a participating provider, an HMO must hold its subscriber harmless from charges in excess of any contractual co-payment amounts,” New York officials write in the opinion. “Accordingly, the contract between the HMO and the provider must prohibit balance billing.”

New York state does not impose balance billing restrictions on providers treating patients who have other types of state-regulated coverage, such as non-HMO health insurance, officials write.

The state has jurisdiction over self-funded employer plans offered by government agencies and churches, but officials say the state does not impose substantive requirements on those plans and does not know what they do about balance billing.

State-regulated plans that want to keep the providers who participate in their networks from balance billing can do so by putting balance-billing provisions in provider contracts, officials write.

Similarly, the state has no jurisdiction over self-funded plans or self-funded plans offered along with limited-benefit health plans, and the state has no laws or regulations preventing providers from balance-billing patients with those types of coverage, officials write.