Ballot Measure 101 asks voters to approve or reject a funding plan adopted by the Legislature to keep providing health insurance coverage to as many as 350,000 low-income Oregonians under the Oregon Health Plan. It's complicated, and lawmakers might be able to come up with a better way to pay for it, but that seems unlikely. A yes vote is the best option available.

In July, lawmakers passed House Bill 2391 to continue funding the Oregon Health Plan for the next two years. Part of that bill is a temporary tax on some hospitals, insurance companies and managed care organizations and the Public Employees Benefit Board, which provides insurance to public employees. Insurance companies would pay 1.5 percent on policies. Hospitals would pay 0.7 percent on net revenue (rural hospitals are exempt).

The plan passed the Legislature with bipartisan support, but three Republican lawmakers, including Rep. Sal Esquivel, R-Medford, launched a campaign to refer the tax to voters. The campaign gathered enough signatures to make the ballot.

Ordinarily Measure 101 would appear on the November ballot, but Democratic leaders called a special election for Jan. 23 so that if voters say no, the Legislature could try to find another way to fund the system during the February legislative session.

Opponents of the tax say it's unfair, and lawmakers should come up with a better plan. Whether that can be accomplished in a one-month session is a big question. The consequences of failure are too serious to take that chance.

Opponents say Oregonians who buy insurance on the individual market would end up paying the tax, passed on by the insurance companies. But part of HB 2391 funds the reinsurance pool that partially reimburses insurers for extremely expensive care. The reinsurance program has stabilized the market, resulting in premiums decreasing by 7.5 percent for 2018. That means that even if insurance companies pass on the 1.5 percent tax — the maximum amount they are allowed to increase premiums under the legislation — policyholders still will pay 6 percent less.

Hospitals taxed 0.7 percent could pass on some of that in increased rates, but if hundreds of thousands of Oregonians lose coverage, they could wind up in emergency rooms when they need care, driving up costs for everyone.

College students, who are required to purchase health insurance to attend public universities, could pay up to 1.5 percent more, but most of them are insured under their parents' policies until age 26 under the Affordable Care Act.

Finally, if this funding mechanism goes away, federal matching funds for Medicaid would disappear, too — as much as $1.3 billion, according to supporters of the plan.

Those supporters include not only the hospitals and insurance companies being taxed but also Senate Republican Leader Ted Ferrioli, the Oregon PTA, the Oregon Nurses Association, the Coalition of Community Health Clinics and AARP.

Oregon has been a national leader in expanding health insurance coverage to more people through innovative funding mechanisms and cost-containment measures. The plan adopted in July to keep that system going for two more years may not be perfect, but it is better than the alternative — putting as many as 350,000 Oregonians at risk of losing health coverage while the Legislature does battle over funding all over again. Without the tax proceeds, lawmakers would have to make painful cuts to the Oregon Health Plan or other parts of the state budget.

The system of taxing providers a little to generate a lot of federal matching funds has been working well for more than 10 years. It would be a mistake to end it now.