Pharmacies all over the country are experiencing delays in prescription orders due to a cyberattack on one of the biggest healthcare technology companies in the nation, Change Healthcare.

Change Healthcare first noticed the “cyber security issue” affecting its networks on Wednesday morning on the East Coast.

It comes amid a major cell outage which has affected millions of customers across the country, crippling 911 services and leaving customers without reception on the biggest networks. That outage may have been caused by “human error“, according to one expert, but a “solar flare” has also been cited as a possible explanation for the cell problems.

But Change Healthcare are in no doubt the problems facing their systems have been caused by a cyber attack. In a statement, Change Healthcare said: “Change Healthcare is experiencing a network interruption related to a cyber security issue and our experts are working to address the matter. Once we became aware of the outside threat, in the interest of protecting our partners and patients, we took immediate action to disconnect our systems to prevent further impact,”

The company added: “We will provide updates as more information becomes available.”

Across the country, pharmacies have issued notices that the attack on Change Healthcare is disrupting their ability to process patients’ orders.

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There is currently no publicly available report on the nature or origin of the cyber security issue plaguing Change Healthcare.

“There is a nationwide outage from some of the largest prescription processors in North America,” Michigan-based Canadian Lakes Pharmacy wrote on social media Wednesday.

The announcement continued, “We CAN receive your RX but for MOST insurance plans we cannot bill your insurance company. If you can wait a day or so to pick up your RX that would be great. If you need it today we can do our best to accommodate individual needs.”

The service outage is expected to last until tomorrow but Change Healthcare has not given a definitive timeline for a service return.