She succeeds Tim Bird, who is taking on the chairman role as he transitions to a consulting role at the Next 15 Communications Group unit.
Bernstein, who also served as general manager of Weber’s Boston outpost, did a nearly dozen-year run at the Interpublic PR flagship.
She joined Weber from Edelman, where she did a four-year stint.
Bernstein will report to M Booth CEO Dale Bornstein.
She praised Bird for “the leadership and vision that brought his agency under the M Booth umbrella.”
Next 15 acquired Health Unlimited’s US division, which was headed by Bird, in 2019.
Health Unlimited and its specialist consultancy Corkery Group were rebranded as M Booth Health, which took the No. 12 slot in O’Dwyer’s rankings of healthcare PR firms with $14.4M in fees for 2020.