From law.com:

Since bursting onto the infomercial scene in 2008, one question has confounded the nation about the Snuggie: Is it a blanket or a garment? Nearly ten years later, we finally have our answer.

The U.S. Customs and Border Protection had categorized the Snuggie as a garment. This made it subject to a 14.9 percent tariff, whereas blankets get hit at 8.5%. AllStar Marketing, which sells Snuggies, balked at that classification. This led to a showdown between AllStar and the Justice Department at the U.S. Court of International Trade, where Judge Mark Allen Barnett settled the question.

Barnett ruled that Customs and Border Protection was wrong to classify Snuggies as garments, according to Bloomberg. In a 32-page decision, he noted that not only is the product marketed as a blanket, depicting consumers “in the types of situations one might use a blanket,” but also that the addition of sleeves alone does not transform the blanket into clothing. Moreover, Barnett rejected the Justice Department’s argument that the item is similar to robes and priestly vestments; unlike those garments, he explained, the Snuggie opens in the back and has no closures.

The decision also referenced the Slanket and the Freedom Blanket, both of which were Snuggie precursors and classified as blankets.