Make the potatoes tender by boiling them in salted water, until they are fork-tender. Immediately after cooking, drain and let cool.
The eggs should be diced, the pickles and celery should be sliced into bite-sized pieces, and the green onions should be chopped. In individual bowls, combine all the ingredients.
Stir together the mayonnaise, sugar, vinegar, sour cream, salt, and pepper in a large bowl.
Potatoes, pickles, celery, eggs, and green onions should be added to the dressing along with the pickles and celery. Make sure all ingredients are evenly distributed by gently folding everything together.
Whether serving it as a side dish or alongside your favorite meal, this Costco Potato Salad goes well with summer meals.