Unionized Costco stores in the U.S. voted to authorize a strike. Here's everything to know about possible Costco strike locations and Arizona impact.

With a master agreement with the Teamsters set to expire in 10 days, affecting 18,000 of the retailer's workers, hundreds last week held practice pickets.

Bryan Fields, a Costco employee in Baltimore and member of Teamsters Local 570, told ABC News that the strike deadline comes after months of stalled conversations, extensions and failed negotiations with the company.

The International Brotherhood of Teamsters, which represents more than 10,000 Costco workers, authorized a nationwide strike to occur in February.

More than 18,000 Costco workers will be walking picket lines in less than two weeks if a labor dispute over wages and benefits is not resolved, according to the Teamsters union. Members voted by an 85% margin to authorize a strike when their current contract expires on Jan. 31, the union announced on Sunday.

The union, which represents more than 18,000 workers at Costco, said 85% of its members voted to authorize a strike.

The Costco Teamsters National Master Agreement, which covers more than 18,000 workers nationwide, expires on January 31.

More than 18,000 Costco workers will be walking picket lines in less than two weeks if a labor dispute over wages and benefits is not resolved, according to the Teamsters union. Members voted by an 85% margin to authorize a strike when their current contract expires on Jan. 31, the union announced on Sunday.

Thousands of Costco workers nationwide voted Sunday to authorize a strike if a contract is not reached by the end of the month.

In pursuit of increased wages and renegotiated employee benefits, more than 18,000 Costco union members nationwide voted to authorize a strike if the wholesale company doesn't agree to their terms by Jan.

A strike authorization vote does not necessarily mean a strike will take place, they are often by unions prior to contract extensions. If the strike goes forward, it’s scheduled to start on February 1. Costco officials have not commented on the matter.