What are the citizenship requirements after receiving an EB-5 green card?

You need a presence in the United States for 30 months of the five-year period of your permanent residency.

In order to be eligible to apply for citizenship, you physically must have been in United States at least 50 percent of the five-year period prior to your application, which roughly means 2.5 years plus one day.

As long as you are in the United States for most of the time and not gone for over six months, there is no problem with continuity of residence.

You can apply for the citizenship after four years and nine months since you got the green card. Before the application, you must have resided in the United States for at least half of the period since you became a permanent resident. If you only had one-year absence from the United States total during the five-year continuous residence, you are qualified to apply for the citizenship. However, you still need to meet the other requirements to be a citizen of the United States. For example, you shall have no criminal record and so on.

In the five years proceeding your citizenship application, you must have been in the United States more than you have been out of the United States, and no trip should have been longer than six months. Short trips are acceptable as long as you spend the majority of your time inside the United States.

You can apply for citizenship at 57 months. If your absence for almost one year was continuous, you need to explain why you were out. Short absences are not a problem, but you need 50 percent physical presence and generally no absences in excess of six months.

You are eligible to apply for your naturalization/citizenship after five years from the date of becoming a lawful permanent resident (technically you can submit the application after four years and nine months). Same for all permanent residents who received their lawful permanent residence through business/employment. One of the qualifications for naturalization is that within those five years, you had to have been physically present in the United States for at least 2.5 years. This is CUMULATIVE not continuous.