WASHINGTON, Dec 23 (Reuters) - Enrollment for health insurance under the U.S. Affordable Care Act dipped to 15.6 million for 2026, Mehmet Oz, the U.S. Centers for Medicare and Medicaid Services administrator, said on Tuesday, from roughly 16 ‌million last year.

The drop comes as federal subsidies, expanded during the pandemic, are set ​to expire on December 31, leading to sharp premium increases in ‍2026. Monthly premiums for subsidized ACA plans, also ⁠known as Obamacare ⁠after the former president, are projected to more than double, rising to an average of $1,904 ‌annually from $888 in 2025.

In a social ​media post, Oz attributed the enrollment decline to CMS actions targeting fraudulent and improper sign-ups. The post was ⁠not accompanied by fresh agency data. ‍The ​most recent CMS report, published this month, shows 19.9% of enrollees renewing coverage - down slightly from 20.5% this time last year.

A ‍recent poll by health policy nonprofit KFF highlighted the potential fallout from the subsidy expiration, with 25% of enrollees indicating they would forgo health insurance in 2026 if their premiums doubled as expected. 

Congress did not renew the enhanced subsidies enacted during the pandemic, leaving ​approximately ‍24 million Americans at risk of steep cost increases starting in January.

Enrollment for ACA plans opened in November and runs until ​January 15. Historically, sign-ups have spiked in early January and have grown year-on-year over the past several years, doubling from about 12 million in 2021 due to the expanded subsidies. Insurers and state health officials expect a drop in 2026 enrollment. 

President Donald Trump and Republican lawmakers have been divided ​for months on a replacement for the subsidies. Republicans have been promising an ACA alternative for over a decade, but have yet to produce one with a passable ‍consensus that retains Obamacare's consumer protections.