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§ 412.3(a) Admissions — when an individual is considered an inpatient
Effective 2013-08-19Amended 2025
For purposes of payment under Medicare Part A, an individual is considered an inpatient of a hospital, including a critical access hospital, if formally admitted as an inpatient pursuant to an order for inpatient admission by a physician or other qualified practitioner in accordance with this section and §§ 482.24(c), 482.12(c), and 485.638(a)(4)(iii) of this chapter for a critical access hospital. In addition, inpatient rehabilitation facilities also must adhere to the admission requirements specified in § 412.622.
Official text
The opening words are the whole point of this cell: this definition is stated FOR PURPOSES OF PAYMENT UNDER MEDICARE PART A. It is not stated as a definition for the conditions of participation. Whether it governs § 485.631(a)(5) is a question the text does not answer.
§ 412.3(b) Admissions — who may write the order
Effective 2013-08-19Amended 2025
The order must be furnished by a qualified and licensed practitioner who has admitting privileges at the hospital as permitted by State law, and who is knowledgeable about the patient's hospital course, medical plan of care, and current condition. The practitioner may not delegate the decision (order) to another individual who is not authorized by the State to admit patients, or has not been granted admitting privileges applicable to that patient by the hospital's medical staff.
Official text
Two limits are stated: who may write the order, and that the decision may not be delegated.
§ 412.3(c) Admissions — when the order must exist
Effective 2013-08-19
The physician order must be furnished at or before the time of the inpatient admission.
Official text
At or before. An order written after the fact is not what this paragraph describes.
§ 412.3(d)(1) Admissions — the two-midnight expectation
Effective 2013-08-19Amended 2025
(1) Except as specified in paragraphs (d)(2) and (3) of this section, an inpatient admission is generally appropriate for payment under Medicare Part A when the admitting physician expects the patient to require hospital care that crosses two midnights. (i) The expectation of the physician should be based on such complex medical factors as patient history and comorbidities, the severity of signs and symptoms, current medical needs, and the risk of an adverse event. The factors that lead to a particular clinical expectation must be documented in the medical record in order to be granted consideration. (ii) If an unforeseen circumstance, such as a beneficiary's death or transfer, results in a shorter beneficiary stay than the physician's expectation of at least 2 midnights, the patient may be considered to be appropriately treated on an inpatient basis, and payment for an inpatient hospital stay may be made under Medicare Part A.
Official text
Note what this paragraph is about: whether an admission is GENERALLY APPROPRIATE FOR PAYMENT. It is not a test of what the word inpatient means.
§ 412.3(d)(2) Admissions — inpatient-only procedures
Effective 2013-08-19Amended 2025
An inpatient admission for a surgical procedure specified by Medicare as inpatient only under § 419.22(n) of this chapter is generally appropriate for payment under Medicare Part A regardless of the expected duration of care. Procedures no longer specified as inpatient only under § 419.22(n) of this chapter are appropriate for payment under Medicare Part A in accordance with paragraph (d)(1) or (3) of this section. Claims for services and procedures removed from the inpatient only list under § 419.22 of this chapter on or after January 1, 2021 are exempt from certain medical review activities until the Secretary determines that the service or procedure is more commonly performed in the outpatient setting than the inpatient setting.
Official text
A list-based route: certain procedures are treated as inpatient regardless of expected duration. The list itself (§ 419.22(n)) is not reproduced here.
§ 412.3(d)(3) Admissions — stays that do not cross two midnights
Effective 2013-08-19Amended 2025
Where the admitting physician expects a patient to require hospital care for only a limited period of time that does not cross 2 midnights, an inpatient admission may be appropriate for payment under Medicare Part A based on the clinical judgment of the admitting physician and medical record support for that determination. The physician's decision should be based on such complex medical factors as patient history and comorbidities, the severity of signs and symptoms, current medical needs, and the risk of an adverse event. In these cases, the factors that lead to the decision to admit the patient as an inpatient must be supported by the medical record in order to be granted consideration.
Official text
So a short stay can still be an inpatient admission. Two midnights is an expectation, not a threshold.
§ 485.631(a)(5) CAH staffing — nurse on duty when there is an inpatient
Effective 1993-05-26
A registered nurse, clinical nurse specialist, or licensed practical nurse is on duty whenever the CAH has one or more inpatients.
Official text
The paragraph that makes the word matter. It uses "inpatients" and defines it nowhere.
§ 485.620(a) CAH beds — number of inpatient beds
Effective 1993-05-26Amended 2025
Except as permitted for CAHs having distinct part units under § 485.647, the CAH maintains no more than 25 inpatient beds. Inpatient beds may be used for either inpatient or swing-bed services.
Official text
The second sentence is the useful one: a bed used for swing-bed services is still counted as an inpatient bed. That says what the bed is; it does not say what the person in it is.
§ 485.620(b) CAH length of stay
Effective 1993-05-26Amended 2025
The CAH provides acute inpatient care for a period that does not exceed, on an annual average basis, 96 hours per patient.
Official text
An annual average, and a ceiling on acute inpatient care. Neither is a definition of inpatient.
§ 485.645 CAH swing-bed approval
Effective 2000-08-01Amended 2025
A CAH must meet the following requirements in order to be granted an approval from CMS to provide post-CAH SNF care, as specified in § 409.30 of this chapter, and to be paid for SNF-level services, in accordance with paragraph (c) of this section.
Official text
Swing-bed care is described here as post-CAH SNF care. Nothing in this section states whether a person receiving it is an inpatient for § 485.631(a)(5).
§ 485.638(a)(4)(iii) CAH clinical records — orders must be in the record
Effective 1993-05-26Amended 2025
All orders of doctors of medicine or osteopathy or other practitioners, reports of treatments and medications, nursing notes and documentation of complications, and other pertinent information necessary to monitor the patient's progress, such as temperature graphics, progress notes describing the patient's response to treatment; and
Official text
This is the provision § 412.3(a) points a CAH to. Read it: it is a record-keeping requirement, not an admission standard. The cross-reference is real and the mismatch is real — both are reproduced rather than reconciled.
§ 409.30(a)(1) SNF care — qualifying hospital stay
Have been hospitalized in a participating or qualified hospital or participating CAH, for medically necessary inpatient hospital or inpatient CAH care, for at least 3 consecutive calendar days, not counting the date of discharge; and
Official text
Effective date and amendment history were not captured for this section in this build; it is cited for the three-day inpatient precondition only.
§ 489.24(d)(2) EMTALA — exception: application to inpatients
(2) Exception: Application to inpatients. (i) If a hospital has screened an individual under paragraph (a) of this section and found the individual to have an emergency medical condition, and admits that individual as an inpatient in good faith in order to stabilize the emergency medical condition, the hospital has satisfied its special responsibilities under this section with respect to that individual. (ii) This section is not applicable to an inpatient who was admitted for elective (nonemergency) diagnosis or treatment. (iii) A hospital is required by the conditions of participation for hospitals under part 482 of this chapter to provide care to its inpatients in accordance with those conditions of participation.
Official text
A third use of the word, in a third context: EMTALA's own responsibilities switch off once someone is an inpatient. Again the word is used, again it is not defined.