Critical Access Hospital 96-Hour Rule

Caroline Billings
Release Date- June 17, 2021
Review Date- April 4, 2022

To receive payment under Medicare Part A, Critical Access Hospitals (CAHs) must have their physicians confirm that patients will be transferred to another hospital or discharged within 96 hours. In 2017, the Centers for Medicare & Medicaid Services (CMS) expressed that the 96-hour rule requirements would be seen as “low priority,” but the restrictions remained requirements during audits and recoupments.

Origin of the 96-Hour Rule

From 2005 to 2008, CMS contracted with several private companies, called Recovery Audit Contractors (RACs), to recover funds from identified payment errors. As part of the contract, the RACs were allowed a commission on the value of identified overpayments as well as a contingency fee. Eighty-five percent of the $992.7 million recovered by the RACs came from inpatient hospitals. Due to the program’s success, CMS implemented it full-time to continue recovering money from short stays deemed “not medically necessary.”

Many hospitals continue to appeal medical necessity denials, but the system is overwhelmed by the backlog. In April of 2014, Congress enacted Protecting Access to Medicare Act of 2014, placing a freeze on RAC review for dates of service between October 1, 2013, and March 15, 2015, in an attempt to mitigate this issue. Along with this, CMS released the two-midnight rule. This rule states that inpatient admissions are usually payable under Part A if the admitting physician expected the patient to require more than two midnights in the hospital (and the medical record supports this expectation). However, Medicare Part A does not generally cover hospital stays under two midnights.

Requirements of Certification

Certifying Physician

  • Certification must be made by a physician who knows the patient’s history, plan of care, and current condition. A physician who serves on a utilization review committee cannot make this decision, as CMS claims the physician does not have direct responsibility for the patient’s care. CMS recognizes the following individuals to certify:
  • The admitting physician of record/ physician on call for them
  • The primary or covering hospitalist
  • The beneficiary’s primary care practitioner
  • A surgeon on call for him or her
  • Emergency or clinic practitioners caring for the patient at the point of inpatient admission


  • The most updated certification requirement requires the certification to be signed prior to the patient’s discharge. For best practices, CAHs should attempt to get the physician’s certification in the record and documented at the time of patient admission.
  • Link- Critical Access Hospitals | CMS– With updates from December 2021, this CMS page details requirements for facilities to be designated as CAHs.