A Long Island internist admitted Thursday in Boston federal court that he ordered hundreds of medically unnecessary brain scans and received nearly $50,000 in cash kickbacks.

Dr., 75, of East Setauket. Kenneth Fishberger pleaded guilty to one count of conspiracy to commit health care fraud before Federal Judicial Service Judge Nathaniel Gorton of the U.S. District Court for the District of Massachusetts.

The doctor, who formerly operated a practice on Belle Terre Road in Port Jefferson, admitted that between June 2013 and December 2019, he conspired with the owner and salesperson of a medical diagnostic company operating in Massachusetts to order 480 transcranial Doppler scans for $100. each in cash, according to a copy of the plea agreement. The diagnostic company’s name was not listed in court documents.

The scheme resulted in more than $891,000 in fraudulent bills to Medicare and private insurance companies, prosecutors said in a press release.

Prosecutors said Fishberger faces up to 10 years in federal prison when he is sentenced in February, but the agreement states prosecutors will recommend a lower sentence.

As part of the plea agreement, Fishberger will also pay $342,876 in restitution and forfeit $48,000 in earnings from the scheme, according to court records. The doctor will also be fined up to $250,000 and prosecutors will recommend post-release supervision for one year following incarceration.

TCD scans are ultrasounds that measure blood flow in parts of the brain, prosecutors said. In an agreed statement of facts, Fishberger admitted that “patient diagnoses were distorted” to get Medicare to pay for the tests.

Court records show the fake diagnoses were initiated by diagnostic company representatives who texted Fishberger to inform insurance companies that patients had blood flow-related disorders in the back of the brain. According to felony information, there were only eight medical reasons why Medicare would pay for TCD ultrasounds.

“(Fishberger) signed numerous prescriptions and orders…that a particular patient had one of these conditions even though he had not diagnosed or diagnosed the patients,” the statement of facts states.

In his statement of fact, he admitted that Fishberger received monthly cash payments based on the number of tests ordered in the previous month.

On one occasion in December 2019, Fishberger received a $900 cash payment from a representative of the diagnostic company at a meeting near a local Starbucks, according to court records.

Fishberger’s attorney in Boston, Zachary Hafer, could not be reached for comment.

Prosecutors said the investigation into the scheme involved officials from the FBI and other federal agencies, including the IRS, Health and Human Services, the Postal Service and the Labor Department.

New York State records show Fishberger has practiced internal medicine since July 1976 and has been board certified in the field since 1980. The New York State Professional Misconduct Board previously disciplined Fishberger in 2004 after he admitted violating public health law by improperly prescribing opioids. State records show that from 1991 to 2001, proper records of these prescriptions were not kept.

In 2014, Newsday reported that Fishberger was working at both Mather and St. Louis in Port Jefferson. Charles reported accepting payments from pharmaceutical companies while serving as co-chairman of a committee that recommended drugs for his hospitals. He previously served as chief of the medical and dental staff at Mather.

Fishberger is scheduled to be sentenced on February 25 in Boston.

Grant Parpan covers Suffolk County and federal courts for Newsday. He is a Long Island native and joined Newsday in 2022.