WASHINGTON (AP) – In one of its last chances to tinker with the president’s signature health care law, the Obama administration is proposing fixes and adjustments for 2018. A draft regulation released Monday would update the health insurance marketplace’s premium stabilization system to reflect concerns that insurers have raised. For consumers, the proposal includes changes that would make it easier to compare insurance plans, as well as a new method for calculating premiums for children, geared to avoiding large increases after a child turns age 21. There’s also language to limit abuse of “special enrollment periods” during which people can get coverage outside of the normal sign-up season. The nearly 300-page rule comes ahead of a difficult 2017 open enrollment season, with many consumers facing big premium increases and less choice.