The parent company announced the big news Thursday, saying they were going to begin a nationwide wind-down of all of their locations in the U.S. ... a whopping 371 locations, all of which will be shuttered in waves over the coming months.

Specifically, there are 4 states that currently host 99 Cents Only stores -- California, Nevada, Arizona and Texas ... and yes, they're all going bye-bye.

The reason ... the parent company says they've experienced significant financial difficulty in the wake of the pandemic ... not to mention inflation and changing consumer demand.

99 Cents Only CEO Mike Simoncic says, "This was an extremely difficult decision and is not the outcome we expected or hoped to achieve."

He adds, "The last several years have presented significant and lasting challenges in the retail environment, including the unprecedented impact of the COVID-19 pandemic, shifting consumer demand, rising levels of shrink, persistent inflationary pressures ... all of which have greatly hindered the Company’s ability to operate."

The company has partnered with Hilco Global to liquidate all its merchandise and to get rid of its furnishing, fixtures, and equipment. Most of the stuff in their stores had stayed at 99 cents for a long while -- since opening in 1982 -- but prices did go up up in 2008.