For purposes of this section, an entity need not be owned by or on behalf of a governmental unit or by a section 501(c)(3) organization, or operated by a section 501(c)(3) organization, in order to be considered a hospital. In addition, for purposes of this section, a hospital does not include a rest or nursing home, continuing care facility, daycare center, medical school facility, research laboratory, or ambulatory care facility.
Filing an amended return under this paragraph (h)(2)(ii)(B) does not extend the time for making any other election. Thus, for example, taxpayers that comply with this section by filing an amended return pursuant to this paragraph (h)(2)(ii)(B) may not elect out of section 448 pursuant to paragraph (i)(2) of this section.
26 C.F.R. §1.448-1