(by Caroline Humer, Reuters) – Americans will pay an average premium of $328 [per person per month] for a mid-tier health insurance plan when the Obamacare health exchanges open for enrollment next week. Couples who earn up to $62,040 will qualify for government subsidies to lower that price, the Obama administration said on Wednesday. …

Prices were lower in states with more competition among insurers and higher in states with fewer [insurance companies], the U.S. Department of Health and Human Services (HHS) said in its report. Americans will be able to sign up for the new plans via online state exchanges beginning on October 1. …

The Obama administration is counting on signing up 7 million Americans in the first full year of [the implementation of Obamacare} through the state exchanges, including 2.7 million younger and healthier consumers who are needed to offset the costs of sicker members.

Debate over whether Obamacare will prove affordable for millions of uninsured Americans has been sharp during the past few months, as states have announced rates. States that have supported the law said it will lead to lower prices. Others that have opposed the reform – including Georgia, Florida, and Indiana – warned of “rate shock” for consumers compared to what they could buy on the individual insurance market a year ago. …

The data is mostly based on 36 states where the federal government will operate the insurance exchange. About 14 other states and the District of Columbia are running their own exchange.

Politics aside, states with the lowest average premium tend to have more insurance companies offering plans, the report said. It said eight issuers on average were selling plans in the states with average premiums in the lowest 25 percent, while states with average premiums in the top 25 percent had only three insurers on average.

Texas has been among the Republican-led states most fiercely opposed to Obamacare, but its monthly rates came in below the national average, HHS said. In Austin, Texas, with 76 plans to choose from, a 27-year-old would pay $169 per month for the lowest cost mid-tier plan. In Dallas-Fort Worth, with 43 plans to choose from, that price was $217 per month, the report said. …

Enrolling enough consumers is key to making Obamacare work economically, with price considered the most important factor driving enrollment, according to insurance industry surveys.

Another concern has been that insurance companies will limit access to doctors in order to keep prices low. …

The law was adopted in 2010 but two of its main pillars, the health exchanges and the expansion of Medicaid, take effect in 2014. Household insurance company names like UnitedHealth Group Inc, Aetna Inc, WellPoint Inc and Humana Inc will sell plans on at least some exchanges. Newcomers such as Medicaid specialist Molina Healthcare Inc will also play a role.

(Reporting by Caroline Humer in New York; Additional reporting by Lewis Krauskopf in New York; Editing by Michele Gershberg and Lisa Shumaker)