It is less risky to get a divorce if you have a ten-year green card, rather than a two-year conditional green card. In marriage-based cases, United States Citizenship and Immigration Services (“USCIS”) issues a ten-year green card to the spouse of a lawful permanent resident or a U.S. citizen based on certain circumstances. The marriage must be more than two years on the date that USCIS approves the case, even if the application was sent before the marriage reached the two-year mark. Once you receive a ten-year green card, there is only one higher immigration status that you can achieve and that is U.S. citizenship.
There is no need to notify USCIS of your divorce, unless you are applying for United States citizenship. You may continue to renew your green card every ten-years without providing any information about your divorce, simply because the I-90 Application to Replace Permanent Resident Card does not require it.
As a permanent resident, you have already proven to the U.S. government that you were in a real marriage. However, if you get a divorce too soon after your green card case is approved, the government could suspect marriage fraud. There is no exact period of time when it is safe to get a divorce, however, you should look at what is reasonable. If you file for a divorce within a week of getting your green card, it is more likely for the government to believe that you committed marriage fraud, compared to someone who waited a year.
A divorce does impact your eligibility for U.S. citizenship. If you are still married and living with your U.S. citizen spouse after getting the ten-year green card, then you only need to be a green card holder for three years to apply for U.S. citizenship. If you are divorced, then you will have to be a resident for five years before you can apply. Some exceptions apply, for example VAWA divorcees are eligible in three years. There is no need to panic if you are divorced from your spouse and you want to become a U.S. citizen. There is nowhere on the N-400 application for your ex-spouse to sign and your spouse does not need to appear at the naturalization interview with you. You must however, provide a copy of all your divorce decrees. You can become a U.S. citizen even after obtaining a divorce after permanent green card issued.