The Environmental Protection Agency (EPA) is issuing final amendments to the federal minor New Source Review (NSR) program in Indian country. We refer to this NSR rule as the "federal Indian country minor NSR program." We are amending this rule in two ways. First, we are expanding the list of emissions units and activities that are exempt from the federal Indian country minor NSR program by adding several types of low-emitting units and activities. Second, we have clarified construction-related terms by defining "commence construction" and "begin construction" to better reflect the regulatory requirements associated with construction activities. We believe both of these changes will simplify the program, and result in less burdensome implementation without detriment to air quality in Indian country. Finally, we have reconsidered the advance notification period for relocation of a true minor source in response to a petition on the rule from the American Petroleum Institute, the Independent Petroleum Association of America and America's Natural Gas Alliance, but we are not changing that provision.