Transparency and Accountability in Medicare Bidding Act of2013 - Directs the Secretary of Health and Human Services (HHS) to delay from July 1, 2013, to a date no earlier than December 31, 2013, the implementation of: (1) round 2 of the durable medical equipment, prosthetics, orthotics, and supplies (DMEPOS) competitive bidding program under title XVIII (Medicare) the Social Security Act; and (2) the Medicare single payment amounts under the national mail order competition for diabetic supplies.

Directs the Secretary to delay the start of round 1 recompete of such DMEPOS competitive bidding program from January 1, 2014, to a date no earlier than six months after the initial implementation of round 2.

Requires the Secretary, acting through the Office of the Assistant Secretary for Planning and Evaluation, to contract three auction experts, a health economist, and an econometrician to work collectively as an auction expert team, led by the auction experts, to independently review and assess all aspects of round 1 re-bid and round 2 of the DMEPOS competitive bidding program, including its design, development, implementation, adequacy of support for Medicare beneficiaries with chronic illness or disabilities, market fairness, sustainability, and functioning.