International Adoption Harmonization Act of 2010

International Adoption Harmonization Act of 2010 - Amends the Immigration and Nationality Act to include in the definition of "child" a child adopted under the age of 18 (16 under current law) who has been: (1) in the custody of, and has resided with, the adopting parent or parents for at least two years; or (2) battered or subjected to extreme cruelty by the adopting parent or a family member residing in the same household.

Includes in the definition of "child," and thus in the exemption from required admissions vaccination documentation, certain children who have been adopted in a foreign country that is a signatory to the Convention on Protection of Children and Cooperation in Respect of Intercountry Adoption (Hague Convention) or who are emigrating from such a country for U.S. adoption.

States that the budgetary effects of this Act for the purpose of complying with the Statutory Pay-As-You-Go Act of 2010 shall be determined by reference to the latest statement titled "Budgetary Effects of PAYGO Legislation" for this Act, submitted for printing in the Congressional Record by the Chairman of the Committee on the Budget of the House of Representatives, provided that such statement has been submitted prior to the vote on passage.