This document contains the results of Task D, Best Practices Guidelines for the Culvert Repair Best Practices, Specifications and Special Provisions Guidelines Project. These guidelines will provide guidance to Minnesota Department of Transportation (MnDOT) engineers in making better decisions on culvert repairs. New materials specifications, special provisions, and standard details will ensure adherence to standardized practices and increase the effectiveness and longevity of repairs. Focus is on repair of centerline culverts of 24 inches to 72 inches in diameter. This Task D document contains the best practices guidelines for replacement, rehabilitation and repair methods for deteriorating culverts. An overview of replacement methods is provided. Rehabilitation and repair methods are discussed in more detail. The methods discussed are the most common culvert rehabilitation and repair methods identified during governmental and industry surveys conducted during Tasks A and B. The final list for inclusion in this guideline was chosen by the authors and the Technical Advisory Panel (TAP). Special provisions and standard details were prepared for the following methods: paved invert, cured-in-place pipe liner (CIPP), sliplining culvert pipe, centrifugally cast concrete culvert lining, spall repair, joint repair, and void filling outside the culvert.