N.M. Admin. Code § 8.370.13.2
These requirements apply to private and public hospitals that as of December 27, 2020 was designated as a critical access hospital (CAH) by the centers for medicare and medicaid services (CMS), or was licensed as a hospital with not more than 50 licensed beds and located in a county in a rural area as defined in Section 1886(d) (2)(D) or Section 1886 (d)(8)(E) of the federal Social Security Act, and provides rural emergency hospital (REH) services in the facility 24 hours per day seven days a week by a physician, nurse practitioner, clinical nurse specialist or physician assistant with a transfer agreement in effect with a level I or II trauma center, which does not have an annual average patient length of stay over 24 hours and satisfies all CMS requirements for reimbursement as a rural emergency hospital (REH). Facilities that were enrolled as CAHs or rural hospitals with not more than 50 beds as of December 27, 2020, and then subsequently closed after that date, would also be eligible to seek REH designation if they reenroll in medicare and meet all the conditions of participation (COP) and requirements for REH.
N.M. Admin. Code § 8.370.13.2