The medical examiner's office says that so far, it has been unable to figure out how Avonte Oquendo died.
An update from the office on Wednesday called the cause and manner of Avonte's death undetermined.
Avonte was the subject of a citywide search after he was reported missing in October.
Avonte, who had autism, was last seen walking out of his Long Island City school on October 4.
Human remains that washed ashore on January 17 in College Point were determined to be of Oquendo four days later.
The family's lawyer has filed a notice of claim, the first step in suing the city.