13 U.S.C. § 141

(a) The Secretary shall, in the year 1980 and every 10 years thereafter, take a decennial census of population as of the first day of April of such year, which date shall be known as the “decennial census date”, in such form and content as he may determine, including the use of sampling procedures and special surveys. In connection with any such census, the Secretary is authorized to obtain such other census information as necessary. (b) The tabulation of total population by States under subsection (a) of this section as required for the apportionment of Representatives in Congress among the several States shall be completed within 9 months after the census date and reported by the Secretary to the President of the United States. (c) The officers or public bodies having initial responsibility for the legislative apportionment or districting of each State may, not later than 3 years before the decennial census date, submit to the Secretary a plan identifying the geographic areas for which specific tabulations of population are desired. Each such plan shall be developed in accordance with criteria established by the Secretary, which he shall furnish to such officers or public bodies not later than April 1 of the fourth year preceding the decennial census date. Such criteria shall include requirements which assure that such plan shall be developed in a nonpartisan manner. Should the Secretary find that a plan submitted by such officers or public bodies does not meet the criteria established by him, he shall consult to the extent necessary with such officers or public bodies in order to achieve the alterations in such plan that he deems necessary to bring it into accord with such criteria. Any issues with respect to such plan remaining unresolved after such consultation shall be resolved by the Secretary, and in all cases he shall have final authority for determining the geographic format of such plan. Tabulations of population for the areas identified in any plan approved by the Secretary shall be completed by him as expeditiously as possible after the decennial census date and reported to the Governor of the State involved and to the officers or public bodies having responsibility for legislative apportionment or districting of such State, except that such tabulations of population of each State requesting a tabulation plan, and basic tabulations of population of each other State, shall, in any event, be completed, reported, and transmitted to each respective State within one year after the decennial census date. (d) Without regard to subsections (a), (b), and (c) of this section, the Secretary, in the year 1985 and every 10 years thereafter, shall conduct a mid-decade census of population in such form and content as he may determine, including the use of sampling procedures and special surveys, taking into account the extent to which information to be obtained from such census will serve in lieu of information collected annually or less frequently in surveys or other statistical studies. The census shall be taken as of the first day of April of each such year, which date shall be known as the “mid-decade census date”. (e) (1) If— (A) in the administration of any program established by or under Federal law which provides benefits to State or local governments or to other recipients, eligibility for or the amount of such benefits would (without regard to this paragraph) be determined by taking into account data obtained in the most recent decennial census, and (B) comparable data is obtained in a mid-decade census conducted after such decennial census, then in the determination of such eligibility or amount of benefits the most recent data available from either the mid-decade or decennial census shall be used. (2) Information obtained in any mid-decade census shall not be used for apportionment of Representatives in Congress among the several States, nor shall such information be used in prescribing congressional districts. (f) With respect to each decennial and mid-decade census conducted under subsection (a) or (d) of this section, the Secretary shall submit to the committees of Congress having legislative jurisdiction over the census— (1) not later than 3 years before the appropriate census date, a report containing the Secretary’s determination of the subjects proposed to be included, and the types of information to be compiled, in such census; (2) not later than 2 years before the appropriate census date, a report containing the Secretary’s determination of the questions proposed to be included in such census; and (3) after submission of a report under paragraph (1) or (2) of this subsection and before the appropriate census date, if the Secretary finds new circumstances exist which necessitate that the subjects, types of information, or questions contained in reports so submitted be modified, a report containing the Secretary’s determination of the subjects, types of information, or questions as proposed to be modified. (g) As used in this section, “census of population” means a census of population, housing, and matters relating to population and housing.