On https://turbotax.intuit.com/, navigate to Products & Pricing and select CD/download products. Select the product that best fits your tax situation and click Buy Now. You will be promoted to select whether you want to purchase/download the product for a Windows or Mac operating system and be directed to the billing workflow. After purchasing, you will be prompted to download immediately.
You can also access your purchased downloads any time you like up to three years after purchase at TurboTax.com. See steps here for more information https://ttlc.intuit.com/questions/1901289-how-do-i-download-the-software-i-purchased-at-turbotax-com
