Federal and state officials have executed a sealed search warrant at the headquarters of a company that runs Medicaid and Medicare plans.

WellCare Health Plans Inc., Tampa, Fla., says it is cooperating with the authorities but has not described the nature of the investigation.

“Our number one priority is making sure that our members have access to needed care and services,” WellCare says in a statement about the search warrant. “Our essential services are operational and will remain uninterrupted.”

WellCare administers health coverage and Medicare Part D prescription drug coverage for about 2.3 million people.