Responding to New Jersey's decision late Tuesday allowing insurers to continue health policies that are scheduled for cancellation, the state's largest carrier said that doing so under the guidelines would not be a viable option for most plans in the individual market because of cost.

The immediate effect of the announcement by Horizon Blue Cross Blue Shield of New Jersey was unclear. Millions of policies are being canceled nationwide, in many cases because they do not meet the Affordable Care Act's minimum standards. The result has been a nightmare for Democrats, largely because President Obama had consistently said that Americans could keep their plans if they wanted to do so.

Still, they represent a very small segment of the market. About 4 percent of New Jersey residents have individual-market plans, not all of those are being canceled, and independent analyses have found that many, if not most, affected subscribers are eligible for premium subsidies that will make new policies purchased through the Obamacare exchange cheaper.

And while many cancellations across the country are effective Jan. 1, the day exchange policies would start - assuming that consumers are able to buy them through the troubled website - the bulk of Horizon's individual subscribers have renewal dates distributed throughout the year.

"In other words, if you had a renewal date any time in 2014, you are not affected by yesterday's announcements and your plan is NOT being 'canceled,' " Horizon spokesman Thomas Vincz wrote via e-mail on Wednesday.

"Some of our members are also exercising their option to early-renew," he wrote, as allowed by New Jersey law. Premiums could rise, however.

Horizon represents more than half the 150,000 individual-market subscribers whose plans are ending.

Obama two weeks ago urged insurance companies and state regulators to allow temporary continuation of plans that do not meet new federal requirements.

At least 18 states have said no, the Commonwealth Fund Blog reported Wednesday.

Pennsylvania has said yes. In the first public reaction to that decision, the state's Blue Cross companies said Tuesday that they would allow subscribers to their low-income Special Care policies to continue through June, with a yet-to-be-determined rate increase.

215-854-2617 @DonSapatkin