Cerity Partners has merged with yet another wealth management practice, Sullivan & Serwitz.

Co-founded by Robert Sullivan and Marshall Serwitz in 1989, Los Altos, Calif.-based S&S manages around $1 billion and entered into the merger in part for succession planning purposes, according to a press release from Cerity Partners.

"Over the last 30 years, we have been fortunate to achieve strong growth and secure positive outcomes for our clients, and we feel Cerity Partners is the best fit for our practice to continue this growth,” Sullivan says in the press release.

S&S will operate under the Cerity Partners name, according to the press release. The companies didn’t disclose the financial terms of the deal.

Founded in 2009, Cerity Partners has more than doubled its assets under management through mergers over the past few months.

Cerity Partners announced a merger in April with the $11 billion Blue Prairie Group. Earlier this month, the company merged with EMM Wealth, a New York-based wealth management firm overseeing $3 billion.

Cerity Partners says it now oversees around $26 billion from offices in California's Orange County and Los Angeles.