New York is planning to demur from some of the Trump administration’s rule changes for Obamacare, including a much shortened enrollment window.

“Market stabilization” regulations announced last week by the Centers for Medicare & Medicaid Services, which runs HealthCare.gov, would cut this year’s open enrollment period in half. It will run from November 1 to December 15, instead of continuing through January 31 as in past years.

However, the federal rules give state-based insurance exchanges, including the New York State of Health, the option of extending their enrollment periods beyond December 15. The Cuomo administration intends to exercise that option but has not settled on final dates, a Health Department official told the New York Torch.

A second CMS rule change gives insurers more leeway in meeting the Affordable Care Act’s “actuarial value standards” for plans offered on the exchanges – a change that was expected to result in marginally lower premium increases, but also higher copayments and deductibles.

In a notice sent to health insurers this week, the New York State of Health said it would use the new, looser standard for platinum, gold, and bronze-level plans, but not for silver plans. This is because the second-lowest silver plan premium offered on an exchange becomes the basis for figuring the tax credits that offset costs for lower-income consumers. A rule change that tends to lower the premium for that one silver plan would also reduce tax credits for all who qualify.

A third CMS rule calls for stricter vetting of people who sign up mid-year through special enrollment periods, which are available to people whose coverage needs change due to certain life events, such as losing a job, moving, or getting married. Concerned that some consumers are gaming the system – going without coverage while healthy, then falsely claiming a life event to acquire coverage when they get sick – CMS will now require documentation for all people who seek special enrollment.

Here, too, the federal government allows state-sponsored exchanges to set their own policies, and New York believes that requiring documentation for 100 percent of special enrollees would unnecessarily inconvenience consumers, the official said.

Despite the policy differences between Washington and Albany, both sides seem to be focused on supporting the Affordable Care Act marketplaces rather than blowing them up.

CMS faces a critical shortage of insurers willing to sell Obamacare policies in many states, and needs to coax plans to stay in the system. Some insurers have lobbied for the shorter enrollment period, to more closely align with their schedule for employer-based coverage, and the new dates for this year match what the Obama administration was already planning for the end of 2018.

New York, meanwhile, has had no shortage of plans willing to participate in its exchange. And the state Health Plan Association has expressed support for a longer enrollment period because New Yorkers signing up late in past years have tended to be younger and healthier – and therefore welcome additions to the insurers’ risk pools.