Superfast fibre-optic broadband is now available in 100 telephone exchange areas currently not covered by commercial providers, the Welsh government said.
It means 190,000 premises can access faster internet speeds.
The Superfast Cymru scheme has a target of 96% of homes and businesses receiving at least 24Mbps by 2016.
It is a partnership between the Welsh government and BT to give 12 counties the faster internet speeds.
The counties targeted are Blaenau Gwent, Bridgend, Caerphilly, Ceredigion, Flintshire, Gwynedd, Anglesey, Merthyr Tydfil, Newport, Rhondda Cynon Taf, Swansea and the Vale of Glamorgan.
Last week Ofcom said Wales' superfast broadband rollout is catching up but still lags behind the rest of the UK.
Ofcom said the proportion of premises in Wales with superfast broadband is up from 48% to 58% in a year, compared to a UK figure of 78%.