New U.S. Postage Rates take effect June 23, 2019, reflecting changes in DIM weight pricing as well as new international weight limitations.
Here are helpful links on the changes:
U.S. Postage Rates Effective June 23, 2019
USPS DIM Pricing Regulations Effective June 23
DIM Sizing Machine, Just In Time For New USPS DIM Pricing
New Postage Statements PS 3600 PM And PS 3605 Effective June 23, 2019