Preheat the oven to 350°F (175°C).
In a large bowl, combine the shredded chicken, salsa, and taco seasoning; stir until the chicken is evenly coated.
Spread the refried beans evenly across the bottom of a 2‑quart casserole dish.
Spoon the chicken mixture over the refried beans, spreading it into an even layer.
Sprinkle the shredded cheddar cheese evenly over the chicken layer.
Bake at 350°F for 20–25 minutes, until the casserole is hot and the cheese is melted.
Remove from the oven and top with crushed tortilla chips, shredded lettuce, pico de gallo, and dollops of sour cream; serve immediately.