Rate of uninsured Americans rises for the first time since Obamacare took effect in 2014

Demonstrators hold signs during a protest against the repeal of the Affordable Care Act outside the Capitol Building in Washington, U.S., March 22, 2017.

Aaron P. Bernstein | Reuters

The rate of Americans without health insurance rose last year for the first time since the Affordable Care Act took effect in 2014.

Roughly 8.5% of the U.S. population, or 27.5 million people, didn't have health insurance at all in 2018, up from 7.9%, or 25.6 million people, in 2017, according to new data released by the U.S. Census Bureau on Tuesday.

Democrats and health-care advocates blamed the rise in uninsured Americans on the Trump administration's attempts to weaken former President Barack Obama's signature health-care law.

"The latest Census numbers prove once again that the Trump-GOP sabotage agenda continues to wreak havoc on American health care and prevent Americans from getting the coverage they need," Leslie Dach, chairman of health-care advocacy group Protect Our Care, said in a statement.

Sens. Kamala Harris, D-Calif., and Bernie Sanders, I-Vt., also accused President Donald Trump and congressional Republicans of sabotaging the Affordable Care Act "at every turn."

The Trump administration has unsuccessfully tried to repeal the ACA or abolish some of its key provisions including the so-called individual mandate, which levied a tax penalty on people who didn't have health coverage.

The percentage of people covered by the federal government's insurance program for the poor, Medicaid, decreased by 0.7% from 2017 to 2018. The administration has made changes to the program, including adopting a new "public charge" rule that threatens to deny green cards or citizenship to immigrants who use Medicaid.

In 2018, the Trump administration cut the advertising budget for ACA's open enrollment period — an annual period of time in which people can sign up for health insurance — by 90%. This resulted in approximately 400,000 fewer people who signed up for health insurance during the 2019 open enrollment period than for 2018 coverage, according to the Centers for Medicare and Medicaid Services.