NEW YORK (MainStreet) — All kinds of data are floating around making the case for or against the cost-effectiveness of the Affordable Care Act, also known as Obamacare.

A report out last week from the the Centers for Medicare and Medicaid Services shows that two-thirds of small-business employees will see their premiums rise under health care reform — 11 million, as opposed to the 6 million for whom premiums will go down.

But proponents of the law say that that those reports are overblown, noting that businesses offering insurance will also see changes in health care tax credits, and that after the dust settles Americans will see their health care costs reduced under Obamacare, especially as more Americans sign up and economists get more clarity on the ACA's progress.

According to eHealth, the Mountain View, Calif., operator of online health insurance exchange provider eHealthInsurance, many households will see heath care costs rise substantially with Obamacare.

But there is a pretty big caveat: The eHealth numbers track only health care consumers who make too much money to qualify for government subsidies (which are available to those with incomes of up to four times the federal poverty level, meaning $45,960 for an individual or $94,200 for a family of four).

Here's what the company's Price Index says:

  • The average premium for an individual health plan selected through eHealth without a subsidy was $274 per month, a 39% increase from the average individual premium for pre-Obamacare coverage.
  • The most recent average premium for plans without a subsidy chosen by families was $663 per month, a 56% increase over the average family premium in February 2013, which was $426 per month.

The average age of individual health care insurance applicants applying through eHealth is 36, and the average size for family enrollment is three family members.

Some other data from the index:

  • 39% of the individual and family applications submitted in the fourth quarter of 2013 at eHealth were from people between the ages of 18 and 34.
  • The average premium for individual policy-holders in the 55-to-64 age range was $520 per month, and 21% of applicants were in this age range.
  • Among 2014 plans selected in the fourth quarter of 2013, the highest average monthly premium for individual plans was in Alaska ($496) and the highest average monthly premium for family plans was in New Jersey ($1,004).

— By Brian O'Connell