RALEIGH, (SGRToday.com) - The hacking of 485,000 Postal Service employees' personal information has led a key union to file a complaint against agency with the National Labor Relations Board (NLRB).

Federal News Radio reports the National Association of Letter Carriers alleges the United States Postal Service didn't alert employees to the breach until November even though the incident occurred in September.

Medical information appears to have been accessed by the hackers, affecting current and former workers with injury incidents between 1980 and 2012.

Affected people have been offered a free year of credit monitoring.

Read the full story at federalnewsradio.com.