Grant Accessibility and Transparency Enhancement Act of 2010

Grant Accessibility and Transparency Enhancement Act of 2010 - Requires the President to establish the National Commission on Earmark Reform to: (1) study the laws and practices related to replacing earmarks with a full grant making process; and (2) develop a plan to transition from congressional member-directed earmarks to a grant making process.

Requires the Commission to propose legislative or regulatory changes to implement: (1) a grant making application and review process under which a panel of subject area experts reviews and awards grant funding on a merit-based system; and (2) a specific governance structure for all grant functions, including grants management, within the federal government.

Requires the Director of the Office of Management and Budget (OMB) to establish the Office of Grant Making within OMB to: (1) direct and coordinate the development of the expert grant award panels and the specific recommendations of the Commission; and (2) be responsible for maintaining Grants.gov.

Prescribes requirements to streamline the role of federal agencies in the grant making process.

Requires all federal grants, both formula and discretionary, from all grant making agencies to be posted on Grants.gov.

Requires the Director to ensure that duplication of effort and dual systems related to online federal grant activity are no longer in effect by merging USASpending.gov into Grants.gov.

Amends the Congressional Budget Act of 1974 to make it out of order in both chambers to consider any legislation or accompanying report that contains any congressional earmark or limited tax or tariff benefit.