Federal and state Medicaid spending is expected to grow annually at a rate of 7.9 percent over the next 10 years, reaching $674 billion by 2017. The rate is significantly higher than the projected rate of growth of 4.8 percent in the general economy and the 6.7 percent rate of growth in overall health expenditures over the next 10 years, according to a report released Friday by the Centers of Medicare & Medicaid Services. The rate also tops the expected Medicare spending growth rate of 7.4% through 2017.

The cost of providing health care to the poor is projected to grow as a share of the federal budget to 8.4% by 2013 from 7% in 2007.

Health and Human Services Secretary Mike Leavitt said the analysis was a reminder that Medicaid spending is on an unsustainable path that might threaten the health of the nation’s most vulnerable citizens. “If nothing is done to rein in these costs, access to health care for the nation’s most vulnerable citizens could be threatened.” he said.

Expenses are substantially greater for the disabled and elderly. A recent report from Avalere Health LLC, a Washington, D.C., consulting company that analyzed data from Medicare has shown that premiums for Medicare drug coverage will rise an average 24 percent for elderly and disabled Americans. The average monthly premium for Humana Inc.'s basic health insurance plan will increase from $9.51 in 2006 to $25.52 in 2008 and to $40.83 in the coming year.

The report released by the Centers for Medicare & Medicaid Services represents the first annual fiscal report on Medicaid, a federal-state partnership.