5G is finally slowly making its way from large carriers to smaller carriers, and Xfinity Mobile is joining the fray. Comcast announced today (May 18) the launch of 5G for Xfinity Mobile customers.

According to Comcast, access to 5G will follow the path set by T-Mobile and will be offered at no additional charge to regular plans. Other carriers, including Verizon, Sprint, and AT&T, will have to choose more expensive plans if they want to include 5G coverage. As always, to take advantage of Xfinity's mobile services, you must be an existing customer of Xfinity's residential Internet service.

If you want to use 5G with Xfinity Mobile, you will need one of two 5G phones offered by the carrier: the $1,199 Samsung Galaxy S20 Plus or the $1,399 Galaxy S20 Ultra. Interestingly, you will need to subscribe to the 5G service through the Xfinity app.

Xfinity Mobile offers a limited "per gigabyte" data option and an unlimited plan. The former allows customers to choose their expected usage before the billing cycle begins: $12 for 1GB, $30 for 3GB, and $60 for 10GB. If more data is needed beyond the initial allocation, it can be exceeded for $12 per additional GB. The unlimited plan is $45/month, but unlike the tiered plans, video streaming is limited to standard definition.

Comcast's addition of 5G access at no extra charge is commendable, but the 1Gbps-plus mmWave data speeds will probably only be available to gigabit subscribers with 10GB or so or unlimited subscribers.

Carriers are eager to advertise mmWave 5G's ultrafast download speeds, often touting hypothetical scenarios in which an entire season of a favorite show can be downloaded in a minute or two Service providers such as Xfinity are not going to attract users with such claims If service providers like Xfinity truly expect to attract users with such claims, their data plans will need to scale accordingly.

Regardless, Xfinity Mobile appears to be an inexpensive path for those interested in 5G access. The carrier's $45 unlimited plan includes 20GB of full-speed data before throttling is activated. Verizon's cheapest plan with 5G access (the head-scratchingly named "Play More Unlimited") sets a single user at twice that amount, $90 per month, before factoring in a $10 automatic payment discount. Verizon's Start Unlimited plan saves $10 per month, but that $10 will be repaid in the cost of adding 5G support.

Verizon's mmWave infrastructure supporting Xfinity's 5G network is currently spread across 34 cities. The full list can be found on the network's website and will continue to grow through 2020. (Verizon's goal is 60 cities by the end of the year.) As we approach the end of the year, Verizon will also be rolling out a 5G network in the sub-6GHz band; Xfinity Mobile customers will have access to that portion of Verizon's network once it is launched.