NSFNET was officially decommissioned in 1995.
The National Science Foundation Network began in 1985 and became operational in 1986 to connect U.S. supercomputing centers with universities and regional research networks. Its high-speed backbone became a major part of the expanding Internet, replacing ARPANET as the central U.S. research backbone.
As commercial Internet providers grew, the government-backed backbone model was phased out. On April 30, 1995, the NSFNET Backbone Service was retired and its traffic moved onto commercial backbone networks and new network-access arrangements. Regional NSFNET networks and other NSF-sponsored programs continued in related roles, so the date refers specifically to the backbone service’s decommissioning.
This transition is often linked with the commercialization of the Internet. It did not mean that the Internet disappeared; instead, responsibility for much of the national backbone shifted from a federally supported research network to privately operated providers.