A data breach may have impacted some personal information of Northwell Health patients.

Some Long Islanders received a letter informing them that patient names, birthdays, addresses and diagnosis information may have been impacted due to a breach by a third-party vendor.

The Northwell Health third-party vendor says its systems were breached back in May.

Northwell Health released a statement, saying, “On November 3, PJ&A issued a media notice announcing that earlier in the year an unauthorized party gained access to its network and acquired copies of certain files from its systems. While none of Northwell’s systems were impacted by this cyberattack on PJ&A, Northwell has been informed by PJ&A that records relating to Northwell’s patients were among the files copied from PJ&A’s network.

Although Northwell is not aware of any evidence of subsequent misuse of the information obtained from PJ&A’s network, Northwell is offering all of its impacted patients complimentary identity theft protection services.

PJ&A is operating a dedicated call center for impacted patients to have their questions answered. They can call 1-833-200-3558.”