July 23 (Reuters) - U.S. pharmacy benefit managers push

patients towards more expensive treatments even when lower-cost

options are available, according to a report by the House

Committee on Oversight and Accountability.

The committee said it has found evidence that pharmacy

benefit managers (PBMs) force drugmakers to pay rebates for

placing their branded drugs in a favorable position on a

formulary or the list of medications covered by various

insurance plans.

A U.S. House of Representatives oversight panel hearing,

which will include executives from top three U.S. PBMs -

UnitedHealth's ( UNH ) OptumRx, Cigna's ( CI ) ExpressScripts

and CVS Health's Caremark, is underway.

PBMs are companies that handle prescription drug benefits

for health insurance companies, large employers, and Medicare

prescription drug plans.

The three largest PBMs have used their position "to enact

anti-competitive policies" and protect their own profits, the

committee added.

It also said that PBMs share patient data across their

several integrated units to steer them towards pharmacies that

are owned by them.

PBMs have also begun moving some operations abroad to avoid

transparency and proposed reforms, the report said.