On April 3rd, USCIS released a news alert announcing that on April 2nd, USCIS will start destroying Permanent Resident Cards, Employment Authorization Cards and Travel Documents returned to USCIS as undeliverable after 60 days. The intended recipients have 60 business days to correct their address and receive the corrected documents. USCIS reminds applicants that they should be reporting a change of address within 10 days of relocation. The USCIS web page, Change of Address Information has the information you need on address change.
Source of Information:
USCIS.gov, 4/3/18, News Alert:
Undeliverable Permanent Resident and Employment Authorization Cards and Travel Documents to be Destroyed After 60 Days