News T-Mobile to Host Q3 2015 Earnings Call on October 27, 2015

Bellevue, Washington — October 22, 2015 — T-Mobile US, Inc. (NYSE: TMUS) will host an earnings call and an extended, open conversation to discuss the company’s third quarter 2015 financial and operational results on Tuesday, October 27, 2015 at 10:00 a.m. Eastern Daylight Time (EDT). Similar to past quarters, prepared remarks will be kept to a minimum in order to provide more time for free-flowing dialogue with analysts, investors, media and consumers. Additionally, T-Mobile will ring the opening bell the morning of October 27th to commence trading on the NASDAQ Global Select Market.

Participants will have multiple ways to submit questions including via phone and Twitter (@TMobileIR using $TMUS). T-Mobile will also take questions via text and respond to some of them on the call (send a text message to 313131, enter the keyword TMUS followed by a space).

Our Twitter feed will have live-streamed video that can be accessed via a mobile device or desktop computer.

T-Mobile US, Inc. will issue a press release and Investor Factbook reporting its results at approximately 7:30 a.m. EDT on Tuesday, October 27, 2015. The press release and Investor Factbook will be posted at the same time on the Investor Relations website at http://investor.t-mobile.com.

Q3 2015 Earnings Call, Livestream and Webcast Access Information

Access via Phone (audio only):

Date: Tuesday, October 27, 2015

Time: 10:00 a.m. (EDT)

Call-in Numbers: 800-432-9830

International: 719-234-7318

Participant Passcode: 9140842

Please plan on accessing the earnings call ten minutes prior to the scheduled start time.

Access via Social Media:

Embedded livestream on Twitter handle: @TMobileIR

Submit Questions via Text or Twitter:

Text: Send a text message to 313131, enter the keyword TMUS followed by a space

Twitter: Send a tweet to @TMobileIR using $TMUS

Access via Webcast:

The earnings call will be broadcast live via the Company's Investor Relations website at http://investor.t-mobile.com. A replay of the earnings call will be available for two weeks starting shortly after the call concludes and can be accessed by dialing 888-203-1112 (toll free) or 719-457-0820 (international). The passcode required to listen to the replay is 9140842.

To automatically receive T-Mobile financial news by e-mail, please visit the T-Mobile Investor Relations website, http://investor.t-mobile.com, and subscribe to E-mail Alerts.

T-Mobile Social Media

Investors and others should note that the Company announces material financial and operational information to its investors using its investor relations website, press releases, SEC filings and public conference calls and webcasts. The Company also intends to use the @TMobileIR Twitter account (https://twitter.com/TMobileIR) and the @JohnLegere Twitter (https://twitter.com/JohnLegere) and Periscope accounts, which Mr. Legere also uses as means for personal communications and observations, as means of disclosing information about the Company and its services and for complying with its disclosure obligations under Regulation FD. The information we post through these social media channels may be deemed material. Accordingly, investors should monitor these social media channels in addition to following the Company’s press releases, SEC filings and public conference calls and webcasts. The social media channels that the Company intends to use as a means of disclosing the information described above may be updated from time to time as listed on the Company’s investor relations website.

About T-Mobile US, Inc.

As America's Un-carrier, T-Mobile US, Inc. (NYSE: TMUS) is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to approximately 59 million customers who are unwilling to compromise on quality and value. Based in Bellevue, Washington, T-Mobile US provides services through its subsidiaries and operates its flagship brands, T-Mobile and MetroPCS. For more information, please visit http://www.t-mobile.com or join the conversation on Twitter using $TMUS.

Investor Relations Contacts:

Nils Paellmann, Vice President, Investor Relations

212-358-3210 or 877-281-TMUS

investor.relations@t-mobile.com

http://investor.t-mobile.com

Media Contacts:

T-Mobile US Media Relations

MediaRelations@T-Mobile.com