Molina Healthcare Inc. on Friday said that Craig Bass, the head of its Michigan health plan, has been named president of its struggling Texas unit.

The Long Beach Medicaid managed care provider also announced Stephen Harris, formerly president of Molina Healthcare of Wisconsin, will succeed Bass as president of Molina Healthcare of Michigan.

Zarina Shockley-Sparling, senior vice president of health care operations, has been serving as interim president of Molina Healthcare of Texas since Morris D. Hairston moved to a new job at the company in November. Shockley-Sparling will return to her business development duties full time, the company said.

“We are pleased to have been able to recruit not one, but two strong leaders from within the Molina Healthcare family to oversee our health plan operations in Texas and Michigan,” said Shockley-Sparling in statement. “Both Craig and Stephen have already demonstrated tremendous success as presidents of our health plans in Michigan and Wisconsin, so we are looking forward to their future achievements in their new roles.”

Shares of Molina Healthcare plunged more than 30 percent on June 7 after the company withdrew its full-year earnings forecast because costs in its large Texas market were exceeding premiums. New premium rates for the Texas health plan are scheduled to take effect on Sept. 1, and Molina plans to ask the state to re-examine those rates based on what the company has experienced.

Prior to joining Molina two years ago, Bass served as a Medicaid regional vice president for Aetna covering the Southwestern region, which included Texas. Before that, he held a number of executive roles with Amerigroup. Harris has been with the company since 2009, having worked on various market expansion and business development initiatives for Molina’s health plans in Missouri, Texas and Illinois before being appointed to the Wisconsin position in 2010.

Shares on Friday were up 1 cent, or less than 1 percent, to $22.36 in midday trading in the New York Stock Exchange.