I found this online. Is this NOT correct?
Most Permanent Resident Cards, commonly known as “Green Cards” (Form I-551), currently in circulation, have an expiration date and are required to be renewed every ten years. This enables the U.S. government to improve the quality of the card and make it less susceptible to fraud/forgery.
According to the DHS’ Customs and Border Protection (CBP), Permanent Residents who have an expired ten-year Card (Form I-551) and are presently outside the U.S. may STILL enter the U.S. without the issuance of a transportation letter provided they have not been absent from the U.S. for more than 180 days.
Please be advised that lawful permanent residents with an expiring/expired Permanent Resident Cards do not lose their legal status in the United States – their lawful permanent resident status does not expire or change. Think of it as an expiring passport (an expiring passport does not change or affect your nationality/citizenship.).
However, they should renew their expiring Permanent Resident Cards in order to maintain acceptable evidence of their permanent resident status and avoid possible difficulties in obtaining employment, benefits, and re-entry into the United States after traveling abroad.
Transportation Companies are authorized to permit boarding of any bona fide Lawful Permanent Resident (LPR) in possession of an expired Permanent Resident Card with a ten-year expiration date and who has not been absent from the U.S. for more than 180 days, if the expiration date on the card is the only reason that the LPR would otherwise not be boarded.
Airlines are to permit boarding without any penalty to the LPR. However, Carriers must be informed that this policy does not apply to Conditional Permanent Resident cardholders. CR-card holders must contact the nearest U.S. Consulate with a DHS-office prior to making travel arrangements to the United States.