CMS Oversight of the Two-Midnight Rule for Inpatient Admissions

Prior OIG audits identified millions of dollars in overpayments for inpatient claims with short lengths of stay. Instead of billing the stays as inpatient claims, they should have been billed as outpatient claims, which usually results in a lower payment. To reduce inpatient admission errors, CMS implemented the Two-Midnight Rule in fiscal year 2014. Under the Two-Midnight Rule, CMS generally considered it inappropriate to receive payment under the inpatient prospective payment system for stays not expected to span at least two midnights. The only procedures excluded from the rule were newly initiated mechanical ventilation and any procedures appearing on the Inpatient Only List. Revisions were made to the Two-Midnight Rule after its implementation. We plan to audit hospital inpatient claims after the implementation of and revisions to the Two-Midnight Rule to determine whether inpatient claims with short lengths of stay were incorrectly billed as inpatient and should have been billed as outpatient or outpatient with observation. We also plan to review policies and procedures for enforcing the Two-Midnight Rule at the administrative level and contractor level. While OIG previously stated that it would not audit short stays after October 1, 2013, this serves as notification that the OIG will begin auditing short stay claims again, and when appropriate, recommend overpayment collections.

Announced or Revised	Agency	Title	Component	Report Number(s)	Expected Issue Date (FY)
Revised	Centers for Medicare and Medicaid Services	CMS Oversight of the Two-Midnight Rule for Inpatient Admissions	Office of Audit Services	W-00-20-35857; A-09-21-03022	2025