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.

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

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.

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

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.

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.

Thousands of Costco Worker Strike as union negotiations falter. Discover key issues, potential impacts, and what’s next for the retail giant.