The short answer is: it can be challenging, but it's not impossible. Finding the exact replacement cushions for outdoor furniture several years after purchase often presents hurdles. Many furniture manufacturers discontinue specific fabric lines or cushion styles within a few years. Changes in company ownership or product lines can also make direct replacements scarce.
However, you have several viable paths. First, contact the original furniture manufacturer with your model number; they may have leftover stock or updated compatible options. If that fails, consider custom cushion shops, which can create new cushions to your exact dimensions using a wide range of weather-resistant fabrics. Another excellent option is to explore retailers specializing in "universal" or "standard size" replacement cushions, which come in common dimensions for chairs, loveseats, and sofas.
Your success largely depends on having accurate measurements (length, width, depth, and corner style) and being flexible with color and pattern. While finding a perfect match years later requires effort, the market for replacement patio cushions is robust, offering solutions to extend the life and comfort of your outdoor furniture.