Hereditary Hemorrhagic Telangiectasia Diagnosis and Treatment Act of 2014 - Amends the Public Health Service Act to require the Secretary of Health and Human Services (HHS) to establish and implement a hereditary hemorrhagic telangiectasia (HHT, a vascular genetic bleeding disorder that causes abnormalities of the blood vessels) initiative to assist in coordinating activities to improve early detection, screening, and treatment of people who suffer from HHT, focusing on advancing research on the causes, diagnosis, and treatment of HHT and increasing physician and public awareness of HHT.

Directs the Secretary to establish the HHT Coordinating Committee to develop and coordinate implementation of a plan to advance research and understanding of HHT, including by: (1) conducting or supporting research across relevant National Institutes of Health (NIH) institutes, and (2) conducting evaluations and making recommendations regarding the prioritization and award of NIH research grants relating to HHT.

Requires the Director of the Centers for Disease Control and Prevention (CDC) to carry out activities with respect to HHT, including conducting population screening and establishing an HHT resource center to provide comprehensive education on and disseminate information about HHT to health professionals, patients, industry, and the public.

Requires the Administrator of the Centers for Medicare & Medicaid Services (CMS) to award grants for research, including an analysis of health care expenditures associated with untreated HHT and costs associated with preventable medical events among Medicare beneficiaries with HHT.