The launch of Obamacare was followed by a nearly 12 percent average decrease in out-of-pocket health spending among all Americans in a two-year span — but premiums rose by the same percentage and by a bigger dollar amount, according to a study released Monday.

The poorest Americans as a group saw an even bigger plunge in out-of-pocket health spending — 21.4 percent, the study published in the journal JAMA Internal Medicine found.

The savings in out-of-pocket health spending for individuals of all incomes averaged $74.

At the same time, the study found that U.S. households on average saw a 12 percent increase in their health-care premiums or monthly charges they pay for insurance coverage, according to the report.

The average premium increase for a household was $232 annually after Obamacare launched.

And people who earn over 400 percent of the poverty level, or $48,240 for a single person, were hit with a premium increase of almost 23 percent in a two-year span.

Overall, the JAMA study identified a shift in health-care spending, with poorer people spending less after the Affordable Care Act was fully implemented, and higher-income households spending more.