Six years after Congress passed the Affordable Care Act the percentage of Americans without health insurance hit record lows with more than 90 percent of people now covered, the US Census Bureau said on Tuesday.

The uninsured population dropped to 29 million people in the US without health insurance in 2015, or 9.1 percent of the population, according to the bureau's 2015 health insurance statistics released on Tuesday. This is down from 33.0 million people and a rate of 10.4 percent the year before.

A rise in both private and government coverage contributed to the increase in 2015, which follows a trend of declining uninsured rates since the bulk of the Affordable Care Act, dubbed "Obamacare," went into effect in 2014.

The largest increase was seen in direct-purchase coverage plans, according to the census bureau. These types of plans include the healthcare exchanges set up by under the Affordable Care Act, as opposed to plans paid for by private employers or government funded health insurance like Medicaid or Medicare.

The uninsured population might be decreasing in size, but the rate at which its shrinking has slowed down. In 2015, uninsured rates dropped by less between 2014 and 2015 than they did the year before.

Uninsured rates were the highest among lower-income groups and hispanics. For households making less than $25,000 a year 14.8 percent were uninsured, compared to 4.5 percent for those taking in more than $100,000. Hispanics reported 16.2 percent without health coverage compared to 6.7 percent among whites.

States that expanded medicaid as part of the Affordable Care act, saw more success in lowering the percent of its population that does not have health insurance compared to states that chose to reject the option.