Humana announced Thursday it will exit Obamacare plans in four states as part of a larger purge on the individual market, the latest insurer to pull back from Obamacare exchanges.

The company said in an earnings release that it is leaving eight of the 19 states in which it offers individual plans starting next year. The individual market is for people who don't buy insurance through their work and comprises a majority of Obamacare.

In four of the eight states, Humana offers plans on the Obamacare exchange and will no longer do so next year, spokesman Tom Noland said.

"They are all states with limited Humana exchange presence," he said.

The exits bring the number of states where Humana provides plans on Obamacare exchanges to 11.

Humana plans to leave another four states that offer individual plans off the exchanges.

The exit comes as Humana is losing money on the individual market.

Humana next year expects to offer individual plans in no more than 156 counties across 11 states, significantly down from the 1,351 counties in 19 states this year.

The insurer also proposed a number of big rate increases for 2017 to address the problems it has having getting healthy enrollees to sign up.

The exits weren't entirely unexpected. Earlier this year, Humana hinted that it is going to have to raise rates and pull out of some individual markets to maintain viability.

The company created a reserve fund at the end of last year in case medical claims outpaced the revenue from premiums. Humana said Thursday it had to increase that reserve by $208 million.

A common problem with many Obamacare insurers has been underpricing their plans, a factor that has led to losses for some insurers when combined with a sicker-than-expected patients.

A recent study from the Commonwealth Fund found that most Obamacare insurers didn't turn a profit in 2014, the year that the Affordable Care Act was implemented.

Humana is the second major insurer to exit Obamacare markets. UnitedHealth previously announced it would leave a majority of its 30-plus markets next year due to financial losses.

The insurer said during its latest financial statement that it expects to lose about $600 million in Obamacare business this year.

Humana's decision comes on the same day the Obama administration announced it would sue to block a merger between it and Aetna and another merger between Anthem and Cigna. The administration said such mergers would hurt consumers by reducing competition.