878

Area code 878 is a part of the telephone numbering plan in the United States, specifically serving regions in Pennsylvania. Geographical Coverage: Area code 878 serves the southwestern part of Pennsylvania. It operates as an overlay for the existing area codes 412 and 724, covering the same geographic areas. This includes major cities like Pittsburgh, as well as surrounding communities in the region. Introduction as an Overlay Code: The 878 area code was introduced in 2001 as an overlay to address the increasing demand for telephone numbers in the region. However, it wasn't put into widespread use until around 2013, when numbers in the 412 and 724 area codes became more limited. As an overlay, 878 provides additional numbering resources without changing existing numbers. Impact on Dialing Patterns: With the introduction of the 878 overlay, 10-digit dialing (area code + phone number) became mandatory for all calls within and between the 412, 724, and 878 area codes. This means that even for local calls within the same area code, the full 10-digit number must be dialed. In conclusion, area code 878 plays a vital role in Pennsylvania's telecommunication infrastructure, particularly in the southwestern part of the state, including Pittsburgh. Its implementation as an overlay area code reflects the growing telecommunications needs and ensures a continuous supply of new phone numbers in a densely populated and economically vibrant region.