Section 412.513 - Patient classification system(a)Classification methodology. CMS classifies specific inpatient hospital discharges from long-term care hospitals by long-term care diagnosis-related groups (LTC-DRGs) to ensure that each hospital discharge is appropriately assigned based on essential data abstracted from the inpatient bill for that discharge.(b)Assignment of discharges to LTC-DRGs.(1) The classification of a particular discharge is based, as appropriate, on the patient's age, sex, principal diagnosis (that is, the diagnosis established after study to be chiefly responsible for causing the patient's admission to the hospital), secondary diagnoses, procedures performed, and the patient's discharge status.(2) Each discharge from a long-term care hospital is assigned to only one LTC-DRG (related, except as provided in paragraph (b)(3) of this section, to the patient's principal diagnosis), regardless of the number of conditions treated or services furnished during the patient's stay.(3) When the discharge data submitted by a hospital show a surgical procedure unrelated to a patient's principal diagnosis, the bill is returned to the hospital for validation and reverification. The LTC-DRG classification system provides a LTC-DRG, and an appropriate weighting factor, for those cases for which none of the surgical procedures performed are related to the principal diagnosis.(c)Review of LTC-DRG assignment.(1) A hospital has 60 days after the date of the notice of the initial assignment of a discharge to a LTC-DRG to request a review of that assignment. The hospital may submit additional information as a part of its request.(2) The intermediary reviews that hospital's request and any additional information and decides whether a change in the LTC-DRG assignment is appropriate. If the intermediary decides that a different LTC-DRG should be assigned, the case will be reviewed by the appropriate QIO as specified in § 476.71(c)(2) of this chapter.(3) Following the 60-day period described in paragraph (c)(1) of this section, the hospital may not submit additional information with respect to the DRG assignment or otherwise revise its claim.