One little-known feature of the Affordable Care Act is the availability of special health plans with low deductibles and copays to consumers whose incomes are low, but not low enough to be enrolled in Medicaid. (For 2015 that's up to $29,175 for a single person, $39,325 for a couple, and $59,624 for a family of four. Details here.)

Unfortunately, many people eligible to buy these plans may never realize it because of the way HealthCare.gov, the site that sells health insurance to individuals in 38 states, displays plan results. Instead, they may end up with plans that, although their premiums are slightly lower, have extremely high deductibles that could put health care out of reach financially.

The plans they’re missing are special versions of the mid-priced Silver plans, the most popular of the four “metal tiers”—Bronze, Silver, Gold, and Platinum—sold on the state Health Insurance Marketplaces.

Whereas regular Silver plans cover about 70 percent of the average person’s health care costs, the special Silver plans cover 73, 87, or 94 percent, depending on the person’s income. That translates into much lower deductibles, copays and coinsurance. The Silver 87 plan is more generous than a regular Gold plan, and the Silver 94 plan is more generous than a Platinum plan. But the customer doesn't pay a higher premium for these plans than for the standard version of the plan. In other words, they’re a fantastic deal.

Here’s the problem. When people in the eligible income range window-shop on HealthCare.gov, the only clue they have that the special plans are available is the fine print on the initial eligibility page. It says, “This household may also be eligible for a cost-sharing reduction on a Silver plan that reduces the out-of-pocket expenses paid for deductibles, copayments, and coinsurance.”

But when the shoppers then click on the button that says “Continue to plans,” the plans with the lowest premiums are displayed first. These are the Bronze plans. But even though the Bronze plans may have somewhat lower premiums, they don’t have the cost-sharing reductions and can have extremely high deductibles.

When the lowest premium isn't the most affordable

Below you'll see the first result from a search we did in Illinois for a single 40-year-old with an income of $20,000, which would qualify them to buy a Silver 87 plan.

It's a Bronze Blue Cross and Blue Shield PPO. Granted, it only costs $37 a month after subtracting the $133 premium tax credit. But look at the plan details: The customer will have to spend $6,000 of his meager income before the plan covers a single service other than preventive care, which is free in all plans.

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The second example from our search is a special Silver 87 PPO from the same company, shown at the top of the page. Yes, the premium is higher: $103 instead of $37 after the credit. But the deductible is only $500, and the plan covers doctor visits for a low copay even before the deductible is met. It’s not captured in the screen shot, but the plan also covers generic drugs at no cost and brand name drugs with a $50 copay before the deductible is met, whereas the Bronze plan won’t pay for prescriptions of any kind until that $6,000 deductible is satisfied.

Finally, the Silver plan has an annual out-of-pocket limit of $1,500, which means that once the consumer has spent that much out of his or her own pocket for health care, the plan will pick up 100 percent of health care costs for the rest of the year. The Bronze plan’s out-of-pocket limit is the same as its deductible, $6,000.