(a) Under regulations prescribed by the Secretary concerned, and to the extent provided for by appropriations, a member of the National Guard or a member of a reserve component of a uniformed service who is not entitled to basic pay under section 204 of this title, is entitled to compensation, at the rate of 1/30 of the basic pay authorized for a member of a uniformed service of a corresponding grade entitled to basic pay--
(1) for each regular period of instruction, or period of appropriate duty, at which the member is engaged for at least two hours, including that performed on a Sunday or holiday;
(2) for the performance of such other equivalent training, instruction, duty, or appropriate duties, as the Secretary may prescribe; or
(3) for a regular period of instruction that the member is scheduled to perform but is unable to perform because of physical disability resulting from an injury, illness, or disease incurred or aggravated--
(A) in line of duty while performing--
(i) active duty; or
(ii) inactive-duty training;
(B) while traveling directly to or from that duty or training (unless such injury, illness, disease, or aggravation of an injury, illness, or disease is the result of the gross negligence or misconduct of the member); or
(C) in line of duty while remaining overnight immediately before the commencement of inactive-duty training, or while remaining overnight, between successive periods of inactive-duty training, at or in the vicinity of the site of the inactive-duty training.
(b) The regulations prescribed under subsection (a) for each uniformed service, the National Guard, and each of the classes of organization of the reserve components within each uniformed service, may be different. The Secretary concerned shall, for the National Guard and each of the classes of organization within each uniformed service, prescribe--
(1) minimum standards that must be met before an assembly for drill or other equivalent period of training, instruction, duty, or appropriate duties may be credited for pay purposes, and those standards may require the presence for duty of officers and enlisted members in numbers equal to or more than a minimum number or percentage of the unit strength for a specified period of time with participation in a prescribed kind of training;
(2) the maximum number of assemblies or periods of other equivalent training, instruction, duty, or appropriate duties, that may be counted for pay purposes in each fiscal year or in lesser periods of time; and
(3) the minimum number of assemblies or periods of other equivalent training, instruction, duty, or appropriate duties that must be completed in stated periods of time before the members of units or organizations can qualify for pay.
(c) A person enlisted in the inactive National Guard is not entitled to pay under this section.
(d)(1) Except as provided in paragraph (2), this section does not authorize compensation for work or study performed by a member of a reserve component or by a member of the National Guard while not in Federal service in connection with correspondence courses of a uniformed service.
(2) A member of the Selected Reserve of the Ready Reserve may be paid compensation under this section at a rate and under terms determined by the Secretary of Defense, but not to exceed the rate otherwise applicable to the member under subsection (a), upon the member's successful completion of a course of instruction undertaken by the member using electronic-based distributed learning methodologies to accomplish training requirements related to unit readiness or mobilization, as directed for the member by the Secretary concerned. The compensation may be paid regardless of whether the course of instruction was under the direct control of the Secretary concerned or included the presence of an instructor.
(3) The prohibition in paragraph (1), including the prohibition as it relates to a member of the National Guard while not in Federal service, applies to--
(A) any work or study performed on or after September 7, 1962, unless that work or study is specifically covered by the exception in paragraph (2); and
(B) any claim based on that work or study arising after that date.
(e) A member of the National Guard or of a reserve component of the uniformed services may not be paid under this section for more than four periods of equivalent training, instruction, duty, or appropriate duties performed during a fiscal year instead of the member's regular period of instruction or regular period of appropriate duty during that fiscal year.
(f) A member of the Individual Ready Reserve is not entitled to compensation under this section for participation in screening for which the member is paid a stipend under section 433a of this title.