AT&T is bringing fiber-to-the-home Internet to five new metro areas this month, boosting its fiber total to 51 metro areas in the US. Milwaukee, Wisconsin has AT&T Fiber now, and later this month the service will arrive in Columbia, South Carolina; Jackson, Mississippi; Knoxville, Tennessee; and Shreveport, Louisiana, AT&T announced today.

AT&T Fiber is available to nearly four million homes and businesses (up from three million in November 2016), but there's still a lot of work left to put fiber in additional cities and expand deployment in those where it's already available. "By mid-2019 we plan to reach at least 12.5 million locations across 67 metro areas with our 100 percent fiber network," AT&T said. The company agreed to hit those numbers in exchange for getting its purchase of DirecTV approved in 2015.

AT&T has more than 15 million Internet subscribers in the US, mainly via the company's old DSL network and its slightly newer fiber-to-the-node service that boosts speeds by putting fiber closer to each home. Fiber-to-the-premises is fastest of all, with download and upload speeds of up to 1Gbps.

While it's not clear how many fiber customers AT&T has so far, the company says about 30 percent of fiber-to-the-home subscribers have selected the 1Gbps tier. AT&T's 1TB-per-month data cap is waived for customers who subscribe to the gigabit plan, which generally costs $70 or $90 a month depending on the city. The lower price has usually been available in cities where AT&T has to compete against Google Fiber.

Of the four million potential customer locations, more than 650,000 are apartments and condo units, AT&T said. You can check out this map to find out which metro areas have AT&T fiber or will get it in the future, or go to this link to check availability at a specific address.

While AT&T's fiber build is a welcome upgrade, there are still many parts of the company's 21-state territory where customers struggle with horribly slow speeds or no service at all. AT&T isn't promising to bring fiber to all of its customers, but it is working on some fixed wireless technologies that could provide faster home Internet speeds than DSL in rural areas.