Celebrity gossip site TMZ reports that Lang filed for divorce earlier this month, citing "irreconcilable differences."
According to the divorce petition, Lang is asking the judge presiding over the case to block her husband's right to be awarded spousal support. D'Andrea also works in the entertainment industry; he is the founder and president of Community Entertainment.
"I thank u all for your inspirational, supportive, positive messages lately," Lang wrote on Twitter. "I am making a necessary change in life and am happy! Be alive!"
Lang and D'Andrea were married in 1997. The couple has a 15-year-old daughter, Zoe. Lang also has two sons from a previous marriage.
Lang is an original B&B cast member, playing the role of Brooke since 1987. In August, the actress announced that she'd signed a new contract with the CBS soap.