People on the low end of the income scale get more help, as will older people, whose premiums are higher.
With an annual income of about $23,000, Fontenot makes too much to qualify for Medicaid. And her state decided not to expand the program, an option the Supreme Court granted last year as it upheld the rest of Obama's law.
But she would qualify for subsidized private coverage in the federally run Texas marketplace. She could apply online, through a call center, by mail or in person.
After the government verifies her identity, legal residence and income, Fontenot would be able to take her tax credit and use it to pick an insurance plan. Coverage takes effect Jan. 1.
She'd have up to four levels of coverage to choose from: bronze, silver, gold and platinum. All cover the same benefits, but platinum has the highest premiums and lowest out-of-pocket costs, while bronze has the lowest premiums and highest out-of-pocket costs.
Fontenot's share of premiums would be capped at 6.3 percent of her income, or $1,450 a year for a benchmark silver plan. She'd have to squeeze about $120 a month out of her budget, and that doesn't include her annual deductible and copayments.
"If I want to stay alive, I'm going to have to budget that in," said Fontenot.
With insurance, she'd switch to a brand-name diabetes drug that does a better job of controlling her blood sugars — and get that mammogram.
"I am not asking for free stuff," she added. "I am willing to do my part."
Like Fontenot, many of the people who'll access the markets Oct 1 will have health problems. It's where the greatest need is.
But two other groups are critical to the program's success: Healthy uninsured people, many of them in their 20s and 30s, and insured people who will switch over from existing individual policies.
Healthy individuals are needed to help pay for the sick.
And with instant feedback via social media, reviews by people switching from existing individual plans could define early consumer sentiment.
Some of those transitioning will be looking for better deals. Others will be there because their insurers canceled policies that didn't meet the law's minimum standards, and they may be upset.
Consumers don't have to decide on Oct. 1. You have until Dec. 15 to sign up if you want coverage by Jan. 1. And you have until next Mar. 31 if you want to avoid penalties for 2014. Fines start as low as $95 the first year but escalate thereafter.
Procrastinate beyond Mar. 31, and you'll have to wait until the next open enrollment period in Oct. 2014, unless you have a life-changing event like job loss, divorce or the birth of a child.
Former Medicare chief Mark McClellan, who oversaw the rollout of seniors' prescription drug benefits for Republican President George W. Bush, says his advice is not to sign up right away, but not to wait too long either. In other words, check things out. Buying health insurance is not as simple as shopping on Amazon.
"This is a milestone along the path but by no means the end of the road," said McClellan. "There's a lot more of a journey to see if it can really succeed."
Three key things to watch for are premiums, choice and the consumer shopping experience.
Premiums so far are averaging lower than what government experts estimated when Congress was debating the law. That's important for policy types, but it may not mean much to consumers. Current low-cost individual market policies are difficult to compare with the new plans, which offer better financial protection and broader benefits.
Plan choices seem adequate, but networks of hospitals and doctors may be tightly restricted to keep premiums low.
The biggest unknown is how consumers will feel about the whole experience. Many will be unfamiliar with health insurance basics, and applying for subsidies may feel like plodding through tax forms.