SEATTLE – The average annual medical bill for a typical American family of four increased 7.4 percent from 2008 to 2009, according to the annual Milliman Medical Index.

The Milliman Medical Index (MMI) measures average annual medical spending for a typical American family of four covered by an employer-sponsored preferred provider organization (PPO) program. The MMI looks at key components of actual medical spending and charts the changes in these components over time, including cost changes for employers and employees.

The total 2009 medical bill for a typical American family of four is $16,771, compared with the 2008 figure of $15,609. The $1,162 increase is the highest measured by the MMI since the 2006 increase of $1,168, when cost trends were at 9.6 percent.

The MMI found that employers are expected to pay $9,9947, or 5.4 percent more than in 2008, while employees are expected to contribute $4,004 toward their health costs, an increase of 14.7 percent, and pay $2,820 in out-of-pocket expenses, an increase of 5.4 percent.

Spending on outpatient care is expected to increase 10.2 percent, the highest area of growth in 2009.

This is the third consecutive double-digit percentage increase tracked by MMI in the amount that employees spend for healthcare services. Milliman said this is primarily due to increased employee contributions, as out-of-pocket cost-sharing trends were more modest.

Overall cost trends measured by the MMI decreased, however. Every category except inpatient and outpatient facility care experienced lower cost trends than those measured in last year's MMI report.

The MMI report notes that employers' lost business, consumer insecurity and provider revenue pressures affect healthcare use, charges for healthcare services and who pays for healthcare. The unprecedented economic uncertainty has accelerated cost increases in some ways while at the same time reducing certain categories of use (such as elective procedures).