The Rochester Epidemiology Project (REP) is a unique records-linkage research infrastructure that has existed since 1966, and allows for population-based medical research in Olmsted County, Minnesota and an expanded region of 27 counties in Southern Minnesota and Western Wisconsin.

The REP was originally funded by the National Institute of General Medical Sciences in 1966 under the direction of Dr. Leonard T. Kurland,[1] a neurologist who started his career at the NIH and moved to Olmsted County, Minnesota when he realized the great benefit to medical research that a population-based records-linkage system could have.

[7] The REP was originally designed to completely cover the health experience of the local population of Olmsted County, Minnesota.

Beginning in 2010, the linkage of electronic medical data from a region extending beyond the Olmsted County, Minnesota area became possible.

In 2018, REP authors extensively described an expanded 27-county region of Southern Minnesota (19 counties: Brown, Watonwan, Martin, Nicollet, Blue Earth, Faribault, Le Sueur, Waseca, Freeborn, Rice, Steele, Goodhue, Dodge, Mower, Olmsted, Wabasha, Winona, Fillmore, and Houston) and Western Wisconsin (8 counties: La Crosse, Trempealeau, Buffalo, Pepin, Eau Claire, Barron, Dunn, and Chippewa)[11] The expanded REP captures and links the medical data of nearly 700,000 persons from the year 2010 to present (about 60% of the 27-county region as compared to the US Census).