Bring a large pot of salted water to a boil. Cook the macaroni according to package directions until al dente. Drain and rinse under cold water until cool.
In a small bowl, whisk together the mayonnaise, apple cider vinegar, sugar, salt, and pepper until smooth.
In a large bowl, combine the cooled pasta, celery, bell pepper, red onion, peas, and parsley.
Pour the dressing over the pasta mixture and toss gently until everything is evenly coated.
Cover and refrigerate for at least 1 hour before serving. Taste and adjust seasoning if needed.
