As far as the US government is concerned, a US permanent resident with a valid green card does not need a passport to return to the US. See this Q&A from the US CBP:United States (U.S.) LPRs do not need a passport to enter the U.S.and see the carrier information guide (page 28):A Lawful Permanent Resident may travel to the United States without a passport with a Permanent Resident Card (Form I-551).However, if you are traveling by airplane or another carrier, they might still require a passport or other travel document before letting you board.As for entering your u201chome countryu201d, the documentary requirements depend on the rules of the particular country involved. However, if you are a national of that country, most countries would require their national travel back to their country with that countryu2019s own passport. Some countries allow expired passports, and, if you make if to the countryu2019s port of entry, you will probably be allowed in if you can prove that you are a national of that country, but airlines and other carriers are not likely to board you unless you have a document as required by that country.Note that US permanent residents (green card holders) can get a US u201cRe-entry Permitu201d, which is a passport-like travel document which can be used for international travel for green card holders who canu2019t or donu2019t want to get a passport from their country of nationality. See this brochure from USCIS:You may also want to get a reentry permit if you plan on traveling outside the United States and cannot or do not wish to get a passport from your home country. Many countries throughout the world may allow you to use a reentry permit much like you would use a passportu2014placing necessary visas and entry and exit stamps in the permitu2014so you may use it as your main travel document. Be sure to check with any country you plan to visit about specific requirements before you travel.However, to travel to a foreign country on this Re-entry Permit, you would still need a visa from the country you are going to visit, and if you are traveling back to your country of nationality, they are unlikely to issue a visa to their own national, so that still wonu2019t help with getting to the country.