The company confirmed an "issue" in a post on X, saying that it's aware of the problem impacting some customers.
Many people are being stuck in "SOS" mode on their phones, unable to send messages or place calls.
Verizon said it's working on the issue, but it was not immediately clear what was causing it or how many users were affected.
A spokesperson said it began at 9 a.m. EST.
Over the weekend, Verizon posted on X about working to restore service after Hurricane Helene tore through the South.
The massive storm caused widespread power outages and fiber damage.
This is a developing story; check back for updates.