Birmingham, Ala. ? Two more HealthSouth Corp. executives agreed to plead guilty Thursday to charges that include filing false tax returns in a scheme to pump up the health service company’s earnings.

They are the 13th and 14th HealthSouth executives to reach plea deals in a scandal that the government claims involves some $3.5 billion in inflated earnings.

Will Hicks, 39, vice president of investments, agreed to plead guilty to conspiracy to make false statements to auditors and maintaining false records.

Richard Botts, 45, a senior vice president, agreed to plead guilty to charges including conspiracy to commit security fraud and falsifying books. He is accused of providing false information to state tax authorities and the Internal Revenue Service to conceal overstated assets and to cover up fraud.

HealthSouth calls itself the largest U.S. provider of outpatient surgery, diagnostic and imaging and rehabilitation services.