It's another day, and there's word of another health insurer pulling back from the individual health insurance market.

The news comes from Kentucky-based Humana, which announced it will compete in the individual market next year in no more than 156 counties.

Currently, the insurer competes in more than 1,300 counties with products sold in both the "on-exchange" and "off-exchange" portions of the individual market.

Individuals and families shop for coverage in the individual market if they don't get health insurance from an employer or government program. It's the portion of the health insurance world undergoing fundamental changes due to the federal Affordable Care Act (ACA), including the government-run exchange marketplaces.

On Tuesday, Connecticut-based Aetna -- which is trying to acquire Humana -- said it was dropping plans to expand on the exchanges.

It should be noted that the federal government currently is challenging the Aetna-Humana merger, saying it could hurt competition.

This summer, Blue Cross and Blue Shield of Minnesota announced plans to reduce choices on the state's MNsure health insurance exchange.

This spring, Minnetonka-based UnitedHealthcare said it would leave 31 of the 34 state exchanges where the insurer currently competes.

To be clear, not all insurers are leaving the exchanges. But for now, the rough headlines continue for the ACA.