Federal policy shifts that eroded the market for Obamacare are likely to drive up premiums for remaining policyholders next year, particularly those who are older and in poorer health, a new report shows.

The most significant changes include the elimination of a penalty for individuals without insurance in last year’s GOP-led tax overhaul and President Trump’s executive order expanding access to association health plans, such as those obtained by trade groups. He also stretched the maximum length of short-term limited duration plans from three to 12 months