Commentors pointed out that determining a patient's expected length of stay is difficult and contradictory to the physician's training. CMS acknowledged that physicians may have trouble estimating length of stay, but stated, "It has been longstanding Medicare policy to require physicians to admit a beneficiary as a hospital inpatient based on their expected length of stay."
If the physician is unable to estimate the length of stay, CMS instructs physicians to continuing treating patients as outpatients until they have enough information to determine whether the patient should be admitted.
In response to additional comments, CMS stated that it expects physicians to make the decision to admit the beneficiary "based on the cumulative time spent at the hospital beginning with the initial outpatient service."
In other words, if the physician makes the decision to admit after the beneficiary arrived at the hospital and began receiving services, he or she should consider the time already spent receiving those services in estimating the beneficiary's total expected length of stay. For example, if the beneficiary has already passed 1 midnight as an outpatient observation patient or in routine recovery following outpatient surgery, the physician should consider the 2 midnight benchmark met if he or she expects the beneficiary to require an additional midnight in the hospital.
Although CMS also stated that the documentation in the medical record needs to support that the physician had reason to believe the patient would stay two midnights, a Medicare review contractor can potentially deem that the documentation is not strong enough and reverse the complex medical decision made by the physician based on what they knew at the time, Mackaman says.