Maintaining high credit card balances can have a significant impact on your credit score. When your credit card balances approach or exceed your credit limits, it can negatively affect your credit utilization ratio, which is a key factor in determining your credit score. High utilization indicates a greater risk to lenders and can result in a lower credit score. Additionally, carrying high balances over time can lead to increased interest charges and potential difficulty in making timely payments, further impacting your creditworthiness.