The court made clear that the ban can not be enforced against "foreign nationals who have a credible claim of a bona fide relationship with a person or entity in the United States", including those who wish to visit or live with family members and students who have been admitted to a US university.
That is likely to be subject to interpretation and litigation. The Ninth Circuit enjoined a provision of the order suspending the travel of refugees into the United States for 120 days and another provision capping the number of refugees allowed into the country at 50,000 for fiscal year 2017. "The Supreme Court now has a chance to permanently strike it down". He claimed it was needed to protect the USA from terrorists, but opponents said it was unfairly harsh and was meant to meet Trump's campaign promise of keeping Muslims out of the United States. The judges said the ban on travel would take effect for foreign nationals who do not have a "bona fide" connection with a person or entity in the United States.
The Supreme Court said lower courts' injunctions preventing the entire ban from taking effect had gone too far because denying entry to "foreign nationals overseas who have no connection to the United States at all. does not burden any American party by reason of that party's relationship with the foreign national".
What about refugees coming from places like Syria or other war-torn countries? Yet the high court has already allowed a for-profit business, Hobby Lobby, to withhold providing contraceptive coverage to employees under the Affordable Care Act based on the owner's religious beliefs.
Are there still big questions?Those groups are regarded as unable to show a substantial and pre-existing tie to a person or institution in the United States. The Supreme Court noted that no foreign national has any right to admission into this country for any reason.
Trump also posted a tweet referring to the court's decision. "The facts tell us that that these refugees already undergo significant vetting - more than anyone who enters the United States - and none has gone on to commit acts of violence".
When does this take effect?For individuals, a close family relationship is required.
Implementing the ban may cause chaos at airports, experts warn.
Is this a win for Trump?
The court also allowed ban on all refugees with no connection to the USA, while agreeing to hear his appeals in the closely watched legal fight.
Second, the executive order said the bans would "temporarily reduce investigative burdens" on US government agencies, allowing them to concentrate on their review of admissions practices.
The move prompted protests and legal challenges which blocked implementation of the ban. The court granted part of that request in its unsigned opinion.
The ban has been in and out of the court systems since its inception January 27.
State Department spokeswoman Heather Nauert said the ban would be implemented starting 72 hours after being cleared by courts.
Is this a final ruling, then?
A prominent Iranian lawmaker has denounced the Supreme Court's partial reinstatement of President Donald Trump's travel ban, claiming that it's an "obvious breach" of the 2015 nuclear deal between Tehran and world powers, including the United States. At that time, the court could endorse its current view of the travel ban or it could do something different.