People seeking affordable health insurance quotes may have to look harder to find them in the near future. Research from Aon Hewitt reveals HMO premiums are expected to increase nearly 10 percent next year.

The projected 9.8 percent rate hike is up slightly from the 9.4 percent seen between 2009 and 2010. Aon attributed the hike to several factors.

Aon says HMO plans are most popular among older people as the coverage features more robust offers at a higher price. PPOs, on the other hand, are less expensive and can be a good option for those who are young and in good health. Aon says HMO plan participants may be a higher risk to insure in general.

Aon Hewitt's HMO principal and leader Jeff Smith says that while employers have tried to mitigate increasing healthcare costs, there is only so much that can be done.

"If HMO rates continue to outpace average health care cost increases, employers may elect to take even more aggressive steps in the coming years, such as eliminating HMO plans altogether," says Smith.