The primary reason your Colorado tax return is still pending is due to delays in the Colorado Department of Revenue's processing system. In recent times, Colorado has experienced significant delays because their online filing system was not fully ready at the start of the filing season. This has caused a backlog as many returns were submitted before the state was prepared to accept and process them, resulting in returns remaining in a "pending" status for weeks or even longer. The state has also been implementing major tax code changes and new credits, which added to the processing delays. Additional factors that can delay your refund include returns filing on paper, errors on the return, additional reviews triggered by the state, or identity verification processes. If the return requires extra validation or if a refund gets intercepted due to debts owed, that can further delay processing and issuance of refunds. Overall, the pending status is because Colorado is still in the process of catching up with a backlog of returns and system updates, as they only recently began accepting and processing e-filed returns after a delay. Taxpayers are advised to allow multiple weeks for processing, and this delay is not uncommon or unique to any single filer.