Common 4G LTE frequencies used by US cellular networks?

Mobile carriers utilize different frequencies on their networks, and knowing those frequency bands is important to ensure phone compatibility with the carrier network.

List of frequency bands used in the US, Europe and Asia (updated 2018):

AT&T
4G LTE Bands - 2, 4, 5, 12, 17*
Frequencies (MHz) - 700*, 850, 1900, 1700/2100

Verizon
4G LTE Bands - 2, 4, 13*
Frequencies (MHz) - 700*, 1900, 1700/2100

T-Mobile (and Metro PCS)
4G LTE Bands - 2, 4*, 12*, 66, 71
Frequencies (MHz) - 600, 700*, 1900, 1700/2100*

Sprint
4G LTE Bands - 25*, 26, 41
Frequencies (MHz) - 850, 1900*, 2500

US Cellular
4G LTE Bands - 2, 4, 5*, 12*
Frequencies (MHz) - 700*, 850*, 1900, 1700/2100


Canada - Bell, Rogers Telus
4G LTE Bands - 4*, 7, 12, 13, 17
Frequencies (MHz) - 700*, 1700/2100*, 2600

Europe
4G LTE Bands - 3, 7, 20
Frequencies (MHz) - 800, 1800, 2600

China, India
4G LTE Bands - 40, 41
Frequencies (MHz) - 2300, 2500

Notes:
Main frequencies/bands are marked with an asterisk "*".
Lower frequencies have better obstacle penetration, but lower bandwidth.
Some carriers may also use parts of their aging deployed 3G bands for 4G LTE transmissions.
There are two common mobile network standards in the US: GSM (Global System for Mobile) and CDMA (Code Division Multiple Acces). Traditionally, Sprint, Verizon and US Cellular use CDMA, while AT&T, T-Mobile and MetroPCS use GSM. CDMA is mostly owned by chip maker Qualcomm. GSM is the most commonly supported international standard, very few countries besides the USA use CDMA.

Most of the western world uses FDD-LTE networks, while China and large parts of Asia use TDD-LTE. One of the main differences between FDD and TDD is the fact that FDD is symmetrical, while TDD allows variable upload/download ratio.
Below is a list of the commonly used LTE frequencies

4G FDD LTE Frequency Bands:
B1 (2100 MHz) IMT
B2 (1900 MHz) PCS
B3 (1800 MHz) DCS
B4 (1700/2100 MHz) AWS
B5 (850 MHz)
B7 (2600 MHz) IMT-E
B8 (900 MHz) GSM
B12 (700 MHz)
B13 (700 MHz)
B17 (700 MHz) - subset of band 12
B18 (800 MHz)
B19 (800 MHz)
B20 (800 MHz)
B25 (1900 MHz) EPCS
B26 (850 MHz) ECLR
B28 (700 MHz) APT
B29 (700 MHz)
B30 (2300 MHz)

4G TDD LTE Frequency Bands (Asia)
B38 (2600 MHz) IMT-E
B39 (1900 MHz)
B40 (2300 MHz)
B41 (2500 MHz)