A new USPS plan could add two days to delivery times for some Americans. Here are the states that could be hit hardest by mail delays.

• The Postal Service's 10-year plan could slow mail delivery times by as much as two extra days.
• The new policies would heavily impact delivery times along the West Coast, as well as parts of Florida and Texas.
• The service cuts could make it even harder for USPS to compete with delivery services like Amazon Prime.

A new US Postal Service plan could tack on as much as two extra days to mail delivery times for some Americans, according to a recent analysis from The Washington Post.

Postmaster General Louis DeJoy announced the 10-year plan- which includes longer first-class delivery timelines, reduced post office hours, and higher prices - in March. The proposal still needs approval from the Postal Regulatory Commission, but would cut the amount of mail that is delivered by plane in half. It would also reduce the distance a piece of mail can travel within a day.

The new policies would heavily impact western states, as well as parts of Texas and Florida, according to The Post's analysis which found the plan would slow mail delivery in 27 states.

Major cities like Seattle, Portland, and Las Vegas could expect to add an extra day to delivery times with the new proposal, the publication found. It also said the plan would disproportionately affect rural communities that rely more heavily on mail.

Here are the 27 states that would be at least partially impacted: Washington, Oregon, Montana, Idaho, Wyoming, California, Nevada, Utah, Colorado, Arizona, New Mexico, Texas, North Dakota, Florida, New York, Minnesota, Missouri, Mississippi, Alabama, Georgia, South Carolina, Virginia, Kentucky, Indiana, Vermount, New Hampshire, Maryland.

A USPS spokesperson said the majority of mail will not be impacted and the changes will only add 1-2 days to about 30% of deliveries.

"Regardless of whether a letter or package travels 300 miles or 3,000 miles, our current standards require 3-day delivery for any destination within the contiguous United States if the drive is greater than 6 hours," the USPS spokesperson told Insider. "That is simply unattainable and forces us to overly rely on air transportation, yielding unreliable service and higher costs."

Read more: Louis DeJoy looks to be safe as head of the USPS. Experts say his plan to save the post office may pummel small sellers struggling to compete against Amazon.

Currently, the standard delivery time for USPS packages is about 2-3 days, but the publication reported the new plan would create average delivery times between 2-5 days. Current USPS standards maintain the 2-3 day delivery margin for mail regardless of its destination, but the new policies would mean mail that travels long distances across the US would have standard delivery times between 4-5 days.

DeJoy said in the initial release that the new policies could create more stability, saying the government agency has not been able to maintain its delivery standards (2-3 day delivery windows at a success rate of 96%) for nearly 10 years. During the beginning of the pandemic, the Postal Service struggled to hit delivery timelines. This time last year, about 31% of mail was delivered outside of the 2-3 day delivery window.

The new standards only apply to the mail that predominantly flows through the US Postal Service, including first-class mail such as letters and newspapers.

Experts told The Washington Post the new delivery standards would represent the most significant delay of US mail in "more than a generation." 21 attorneys general issued a statement opposing the changes earlier this week.

The attorneys general said that the new plan reflects a "flawed philosophy that would prioritize the services it offers in competitive markets," such as package delivery, "over those that it alone provides and on which countless Americans depend."

When the plan was released, industry officials warned that the service cuts could make it even more difficult for the Postal Service to compete with delivery services like Amazon Primes, FedEx, and the United Parcel Service.

In the initial announcement, DeJoy said the plan will lower operating costs and help the group avoid $160 billion in projected losses - more than double its annual revenue in 2020.

Read The Washington Post's full report.