The Society of Professional Engineering Employees in Aerospace said Friday that ballots are scheduled for mailing by next Thursday and will be due by March 18.
The union has said it's disappointied the offer does not provide pensions for new employees. They would have a 401(k) retirement plan instead.
However, the union says accepting the company's last offer would lock in "considerable improvements" achieved since the company's initial offer.
The 7,400 technical workers have already given their union strike authorization.
The 15,500 engineers represented by the same union approved a four-year Boeing contract in ballots tallied Feb. 19.
The engineers and technical employees work on plans for new planes and solve problems that arise on the factory floor.