Is there a minimum income necessary to use the ACA?

Nope. These are the only eligibility requirements: https://www.healthcare.gov/quick-guide/eligibility/

The issue may be that you can’t afford a marketplace plan if your income is too low, though low income will allow you to qualify for generous subsidies.

No. Anyone who can afford the insurance premiums qualifies.
If you don’t make enough, say, you have no money at all, then you qualify for Medicaid.
For those who make too much for Medicaid, but not enough to afford the insurance premiums, they may fall through the cracks and have nothing at all.

The ACA is a set of laws governing ALL health insurance providers. It is not.a kind of health insurance itself. If you have health insurance of any kind your provider operates under ACA laws.

^^Not completely true. There are insurance policies that operate outside of the ACA marketplace and are exempt from having to follow all of the ACA regulations.

Can you give me a example?

Plans outside of the exchange. Here’s one link https://www.ahix.com

Lots of companies offer “temporary insurance” too. It’s s way around I think.

If you get insurance outside of the exchange you still had to pay the penalty. I think Trump did away with the penalties altogether though. I’m nit sure if that passed.

Your link can not be found.

As I understand it “The Exchange” was designed to give uninsured folks a way to quickly compare companies and rates, kind of like Travelocity or something.
I have never used the exchange because Rick got insurance, BCBS, through his job.
BCBS still has to comply with the ACA because the ACA are the laws governing all health insurance companies whether you sign up through the “exchange,” have the money sign up with any insurance company you want because money is no obsticle, or get it through your employer or what. They ALL have to comply with the ACA laws.

The penalty is for those who can afford insurance but don’t get it. Has nothing to do with “The exchange.”

You can get short term insurance that is not compliant and you pay the penalty. You can keep renewing the short term, it’s sort of a loophole.

I have my insurance through ACA. Only BCBS offers insurance where I live that is compliant with ACA. BCBS has a monopoly in my county, and surrounding counties, and charge a fortune. I can get non ACA insurance from other companies, but it’s not good coverage if you actually have health problems.

https://www.healthinsurance.org/faqs/what-happens-if-i-buy-insurance-but-it-doesnt-meet-acas-minimum-essential-benefits-standards/