While Texas employers shunned health maintenance organizations as an insurance option for workers during the last decade, a study shows a slight increase in HMO enrollment. The Texas Health Market Review, an annual publication of Minneapolis-based health economist Allan Baumgarten, found that enrollment in Texas HMOs increased 3.9% in 2008 and 7% in 2007, primarily because of Medicaid, Medicare, and the state's Children Health Insurance Plan.