For the purpose of this part:

(a) Museum means a public, tribal, or private nonprofit institution which is organized on a permanent basis for essentially educational, cultural heritage, or aesthetic purposes and which, using a professional staff:

(1) Owns or uses tangible objects, either animate or inanimate;

(2) Cares for these objects; and

(3) Exhibits them to the general public on a regular basis.

(i) An institution that exhibits objects to the general public for at least 120 days a year shall be deemed to meet this requirement.

(ii) An institution that exhibits objects by appointment may meet this requirement if it can establish, in light of the facts under all the relevant circumstances, that this method of exhibition does not unreasonably restrict the accessibility of the institution's exhibits to the general public.

(b) The term “museum” in paragraph (a) of this section includes museums that have tangible and digital collections. Museums include, but are not limited to, the following types of institutions, if they otherwise satisfy the provisions of this section:

(1) Aquariums;

(2) Arboretums;

(3) Botanical gardens;

(4) Art museums;

(5) Children's museums;

(6) General museums;

(7) Historic houses and sites;

(8) History museums;

(9) Nature centers;

(10) Natural history and anthropology museums;

(11) Planetariums;

(12) Science and technology centers;

(13) Specialized museums; and

(14) Zoological parks.

(c) For the purposes of this section, an institution uses a professional staff if it employs at least one staff member, or the fulltime equivalent, whether paid or unpaid primarily engaged in the acquisition, care, or exhibition to the public of objects owned or used by the institution.

(d)(1) Except as set forth in paragraph (d)(2) of this section, an institution exhibits objects to the general public for the purposes of this section if such exhibition is a primary purpose of the institution.

(2) An institution that does not have as a primary purpose the exhibition of objects to the general public but which can demonstrate that it exhibits objects to the general public on a regular basis as a significant, separate, distinct, and continuing portion of its activities, and that it otherwise meets the requirements of this section, may be determined to be a museum under this section. In order to establish its eligibility, such an institution must provide information regarding the following:

(i) The number of staff members devoted to museum functions as described in paragraph (a) of this section.

(ii) The period of time that such museum functions have been carried out by the institution over the course of the institution's history.

(iii) Appropriate financial information for such functions presented separately from the financial information of the institution as a whole.

(iv) The percentage of the institution's total space devoted to such museum functions.

(v) Such other information as the Director requests.

(3) The Director uses the information furnished under paragraph (d)(2) of this section in making a determination regarding the eligibility of such an institution under this section.

(e) For the purpose of this section, an institution exhibits objects to the public if it exhibits the objects through facilities which it owns or operates.