(NewsNation) — The U.S. Postal Service will raise shipping prices in early 2025 while keeping the cost of first-class stamps unchanged.

The proposed price hikes, which would take effect Jan. 19, include a 3.2% increase for Priority Mail and Priority Mail Express services. USPS Ground Advantage rates would rise by 3.9%, while Parcel Select services would see the steepest increase at 9.2%.

The price adjustments were approved by the USPS Board of Governors and have been filed with the Postal Regulatory Commission for review.

The new rates require approval from the commission before taking effect.

The Postal Service said it will not increase prices for Mailing Services in January, meaning the cost of sending regular letters will remain the same.

The rate changes are part of “Delivering for America,” the agency’s 10-year modernization plan to achieve financial sustainability. The adjustments will help support $40 billion in planned investments in personnel, technology and infrastructure improvements, according to postal officials.

Unlike mailing service rates, which are tied to the consumer price index, shipping service prices are adjusted based on market conditions.

The Postal Service, which receives no tax dollars for operating expenses, relies on postage and product sales to fund its operations.