This approval comes two years after the deal was first announced. The deal, in case you need a refresher, is a $26 billion all-stock merger.
The deal will reduce the number of national wireless carriers from four to three, which meant that there could possibly be consumer price increases,
The two companies have said that they plan to increase 5G spending and investments in rural telecoms infrastructure.
The promise led Federal Communications Commission Chairman Ajit Pai to approve the merger, and recommend it to his colleagues last year.
The DoJ approved the deal in July, however, after both Sprint and T-Mobile agreed to sell $5 billion in prepaid wireless and spectrum assets to Dish Network Corp.
Watch the video above for his full answer.