BN 님이 친절하게 링크까지 주셨는데…
배우자가 시민권자인 상태에서 3년 결혼생활 유지입니다.
Living in marital union with the citizen spouse for at least 3 years preceding the time of filing the naturalization application (the citizen spouse must have been a U.S. citizen for those 3 years).