Initially when T-Mobile announced that it was merging with Sprint, a deadline for the deal to be completed had been set for March 29, 2019. However, thanks to a holdup with the Department of Justice's Antiturst chief, that date has been missed.

As a result of this, T-Mobile is delaying the merger completion date with a new deadline now set for July 29.

A little over a week ago, we learned that the Antitrust division within the DOJ wasn't very keen on approving the deal — going as far to say that it was unlikely T-Mobile and Sprint's merger would be allowed. In light of that, a delayed deadline for this isn't very surprising.

In an interview with CNBC, Antitrust Division head Makan Delrahim said:

I have not made up my mind. The investigation continues. We've requested some data from the companies that will be forthcoming. We don't have a set number of meetings or a time line. If the case is there for us to challenge a transaction or suggest changes, we will do that.

A lot of scrutiny has surrounded T-Mobile and Sprint joining forces ever since the merger was announced a year ago. The carriers have been promising lower prices and better service for consumers, but critics are worried about the lessening competition this would result in the U.S. wireless space.

T-Mobile and Sprint Merger FAQ: The good, the bad, and the ugly