; or . (4) Effective date The amendments made by this subsection shall take effect on the date of the enactment of this Act and shall apply to transportation furnished on or after such date. (b) Medicaid program integrity measures related to coverage of nonemergency medical transportation (1) Gao study Not later than two years after the date of the enactment of this Act, the Comptroller General of the United States shall conduct a study, and submit to Congress, a report on coverage under the Medicaid program under title XIX of the Social Security Act of nonemergency transportation to medically necessary services. Such study shall take into account the 2009 report of the Office of the Inspector General of the Department of Health and Human Services, titled Fraud and Abuse Safeguards for Medicaid Nonemergency Medical Transportation (OEI–06–07–003200). Such report shall include the following: (A) An examination of the 50 States and the District of Columbia to identify safeguards to prevent and detect fraud and abuse with respect to coverage under the Medicaid program of nonemergency transportation to medically necessary services. (B) An examination of transportation brokers to identify the range of safeguards against such fraud and abuse to prevent improper payments for such transportation. (C) Identification of the numbers, types, and outcomes of instances of fraud and abuse, with respect to coverage under the Medicaid program of such transportation, that State Medicaid Fraud Control Units have investigated in recent years. (D) Identification of commonalities or trends in program integrity, with respect to such coverage, to inform risk management strategies of States and the Centers for Medicare & Medicaid Services. (2) Stakeholder working group (A) In general Not later than one year after the date of the enactment of this Act, the Secretary of Health and Human Services, through the Centers for Medicare & Medicaid Services, shall convene a series of meetings to obtain input from appropriate stakeholders to