A recent study has revealed that close to 59.1 million people in the United States do not have health insurance.
That was up 400,000 compared to the whole of 2009 and up nearly three million from 2008, when 56.4 million Americans were uninsured for at least part of the year, the study by the Centers for Disease Control and Prevention (CDC) said.
The uninsured in the United States are seven times as likely as those with health coverage to forgo health care due to the high cost, and that can lead to poorer health and greater medical expenditures in the long term, the study said.
President Barack Obama's signature health care reforms became law at the beginning of 2010, when interviews to gather data used in the study were conducted.
Under the health care reform law, coverage will be expanded for millions of uninsured Americans and insurance companies are barred from refusing coverage to Americans with pre-existing medical conditions.
But many provisions of the law do not kick in until several years from now.
Health insurance in the United States is usually provided by employers, and unemployment has risen from 8.5 percent of the workforce in March last year nearly 10 percent this year.
Most of the uninsured were adults aged 18-64, the study found.
The government-funded Medicare program provides near-universal coverage for senior citizens, and expansions to Medicaid and the Children's Health Insurance Program have increased coverage for under-18s.
But 8.7 million children in the United States spent part of the year prior to the study uninsured, and 3.4 million had been without health coverage for more than a year at the time of the interview for the study.
Nearly 10 times as many adults -- 30.4 million -- went without coverage for more than 12 months in the first quarter of this year, pushing the number of long-term uninsured adults in the United States up by 1.1 million at the beginning of this year compared to all of 2009.