The number of workers covered by employment-based health benefits dropped 4 percentage points from 2003 to 2004, according to a new study. In 2004, there were 59.8% (174.2 million) workers covered, down from 63.6% a year earlier.

“The erosion in employment-based health benefits is expected to continue … as long as the cost of providing health benefits continues to increase,” according to report authors. The study was conducted by the Washington-based Employee Benefits Research Institute, which released findings Monday.

A clear majority of Americans with healthcare coverage receive it through an employer, either their own or a family member’s.

The larger the employer, the more likely a person would be to have healthcare coverage. Individuals with a family leader working at a company with fewer than 10 workers had a 31% probability of being uninsured, the study found. The probabilities of being insured at larger firms were as follows: 26% if firm employed 10 to 24 workers; 20% for 25 to 99 workers; 14% for 100 to 499 workers; 12% for 500 to 999 workers; and 11% for 1,000 or more workers.

The full report can be seen at www.ebri.org/pdf/EBRI_Notes_10-2005.pdf.