The national scanning score for the week ending March 11 was 97.11 percent, down from one week earlier.
Western (97.49 percent) led the areas, followed by Southern (97.28 percent) and Eastern (97.14 percent).
Forty-five districts exceeded 97 percent, beginning with Arkansas (98.22 percent). Portland (97.97 percent) finished second, while San Diego (97.76 percent) climbed eight spots to take third.
Scanning allows customers to track their packages and other mail. It also helps the Postal Service improve efficiency and network management.
Informational videos about scanning are available at USPS-TV.