It’s finally here. Beginning Tuesday uninsured Americans, including about 1 million Arizonans, will be able to compare plans from private insurance companies, figure out if they qualify for a subsidy to help pay for coverage, and enroll in a plan that will take effect Jan. 1.

Yes, this is Obamacare.

And while several important provisions already have kicked in, Oct. 1 marks the beginning of the largest phase in the law that benefits Americans.

It’s a landmark law, upheld by the U.S. Supreme Court, and while there will no doubt be kinks to work out and improvements to be made, the Affordable Care Act stands to improve the life and health of Americans.

Arizonans will pay less than the national average for health insurance, according to information from the federal Health and Human Services agency.

Arizona is one of 36 states that will participate in the federal health-care exchange instead of running its own marketplace.

It’s a complicated law, yes. But so are sweeping programs like Medicare and Social Security that we now consider bedrock parts of American life.

We anticipate that as people become familiar with the ACA that understanding will increase and reactionary opposition to “Obamacare” will fade.

Polls show that Americans don’t have a favorable view of Obamacare, but that few say they understand it.

Here’s the short version:

If you have insurance through your employer, and you’re satisfied with it, you don’t have to do anything.

If you don’t have insurance and you have a low income, you may qualify for Medicaid.

If you don’t, you will likely qualify for subsidies to buy health insurance — these are the plans that roll out on Tuesday.

You are not buying insurance from the government, because the plans are from private insurance companies.

This isn’t “government health care.”

If you do have insurance through your employer, and your employer pitches in to cover the cost of premiums, as many do, then you can buy a different policy through the health care exchange but you cannot receive a subsidy to help cover the cost.

The Star has a special section titled “Health Care Law and You” in today’s paper.

The stories explain the details of how the ACA will work in Arizona, where to go for help with figuring out which plan works best for you, and what penalties will kick in for those who don’t get health insurance.

Health insurance is a funny thing — by its nature people often don’t understand its benefits or limitations until they need it.

For example, most Americans won’t have reason to understand the importance of the ACA provision that eliminated the lifetime dollar limit on benefits, because that only becomes an individual issue in the face of a serious illness or injury.

Similarly, the prohibition on insurance companies canceling your policy if you become seriously, and expensively, ill — as was common practice and legal before Obamacare — only matters if you are the person dropped in the middle of cancer treatment.

And if you think you don’t need health insurance because you’re healthy, think again because you never know when illness or injury will strike.

Appreciate your good fortune and know that, thanks to Obamacare, when you do become ill or have an injury, insurance companies can no longer charge you more or deny you a policy because you have a pre-existing medical condition. Again, this is one of those benefits many people don’t notice but is crucial nonetheless.

As people begin to enroll in the health plans, there will no doubt be glitches and problems. It’s bound to happen with such a large system ramping up.

The upside is that there is time before the plans become effective and you can enroll into March. As long as you have signed up for a plan by Dec. 15, your plan will begin Jan. 1.

Many have spent much time, energy and money trying to fight Obamacare.

But it’s here.

The true measure will be in how it works on the ground — that’s what counts.