The OSC, an independent watchdog agency funded by Congress, has the task of investigating government whistleblower claims. The agency will get $22.9 million in funding next year.
OSC spokesman Nick Schwellenbach told CNBC that since approximately May 2014, the agency has received more than 150 complaints from VA employees who allege retaliation for disclosing threats to patient health or safety.
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"We have closed more than 30 of these retaliation complaints, and obtained corrective action on behalf of at least 15 whistleblowers," he said.
In a statement, the VA said: "Employees who step forward to raise concerns have a direct bearing on the veteran outcomes we deliver. As VA transforms and improves the care and services we provide each day, we know there is no better source of ideas for improvement than from our employees."
Dr. Phyllis Hollenbeck featured prominently in CNBC's documentary, "Death & Dishonor: Crisis at the VA," which was released in November 2013 and brought to light patient care and staffing issues at the Jackson VA hospital.