You cannot vote in almost any election in the U.S. unless you are a full U.S. citizen. If you try to vote in an election as a green card holder, even if you have applied for citizenship, you may be subject to deportation from the U.S. as well as criminal penalties. Also, you may feel eager to start participating in the political process once you become a citizen, but you must wait until you are properly registered to vote.
There are a few cities, such as San Francisco and Chicago, in which foreign nationals can register to vote in local elections. These may include not only legal permanent residents but also people on non-immigrant visas and even undocumented immigrants in some cases. Certain cities in Maryland also have taken steps to allow foreign nationals to vote. Since these exceptions are very narrow, you may want to check with an attorney before you attempt to vote or register.
The Naturalization Process
Most foreign nationals become eligible to apply for citizenship once they have spent five years as a green card holder in the U.S. Some types of foreign nationals, especially spouses of U.S. citizens, may be able to apply for citizenship after a shorter period, such as three years. Regardless of the waiting period for eligibility, you can send your naturalization application to USCIS a maximum of 90 days before you are eligible to become a citizen.
USCIS then will make sure that you meet the various requirements for naturalization, such as continuous residence in the U.S., physical presence in the U.S., and good moral character. You can consult an attorney if you are not sure whether you meet the requirements. Applying for citizenship when you are ineligible may be a waste of money at best and put your legal status in the U.S. in jeopardy at worst. Ultimately, you will need to go through a naturalization interview at a USCIS office. You will be asked about the contents of your application and tested on civics and the English language.
The final step in the naturalization process is attending a naturalization ceremony, at which you will take an oath of allegiance to the U.S. Once you have taken the oath and received your naturalization certificate, you will be a U.S. citizen. This means that you are eligible to register to vote in elections at federal, state, and local levels.
Registering to Vote
At your naturalization ceremony, USCIS will give you information on how to register to vote. Or you may get this information from a voter registration group that is not affiliated with any political organization and is approved by USCIS. You can complete your voter registration forms and give them to the voter registration group, which will submit them for you after the naturalization ceremony.
If you do not want to register to vote at the naturalization ceremony, you can register to vote later at certain government offices. You might be able to register at the Department of Motor Vehicles (or the equivalent agency) in your state or at a post office.