The TRICARE
DRG-based payment system is modeled on the Medicare PPS. Although
many of the procedures in the TRICARE DRG-based payment system are
similar or identical to the procedures in the Medicare PPS, the
actual payment amounts, DRG weights, and certain procedures are
different. This is necessary because of the differences in the two
programs, especially in the beneficiary population. While the vast
majority of Medicare beneficiaries are over age 65, TRICARE beneficiaries
are considerably younger and generally healthier. Moreover, some
services, notably obstetric and pediatric services, which are nearly
absent from Medicare claims comprise a large part of TRICARE services.
3.2.2 Assignment Of Discharges To
DRGs
TRICARE uses a “Grouper” program
to classify specific hospital discharges within DRGs so that each hospital
discharge is appropriately assigned to a single DRG based on essential
data abstracted from the inpatient bill for that discharge. The
TRICARE Grouper is developed by Health Information Systems, 3M Health
Care, and is based on the Centers for Medicare and Medicaid Services
(CMS) Grouper, but it also incorporates the PM-DRGs, and DRGs 899
and 898.
3.2.2.1 The Medicare Code Editor (or
other similar editor programs) is an integral part of the CMS Grouper
and serves two functions. It helps to ensure that the claim discharge
data is accurate and complete, so that it can be correctly grouped
into a DRG. It also “edits” the claims data to identify cases which
may not meet certain coverage requirements or which might involve
inappropriate services. Contractors are not required to use any
“Editor” program, but it is recommended since the first function will
facilitate claims processing, and the second function may be useful
in assessing coverage under TRICARE.
3.2.2.2 The classification of a particular
discharge is based 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 discharge status. (Contractors
are required to use the expanded diagnosis and procedure code fields.)
For neonatal claims (other than normal newborns), it also is based
on the newborn’s birth weight, surgery, and the presence of multiple,
major and other problems which exist at birth. For services provided
before the mandated date, as directed by Health and Human Services
(HHS), for International Classification of Diseases, 10th Revision
(ICD-10) implementation, the birth weight is to be indicated through
use of a fifth digit on the neonatal International Classification
of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) diagnosis
code. For services provided on or after the mandated date, as directed
by HHS, for ICD-10 implementation, the birth weight is to be indicated
through use of a sixth digit on the neonatal ICD-10-CM diagnosis
code.
3.2.2.2.1 In situations where the narrative
diagnosis on the DRG claim does not correspond to the numerical
diagnosis code, the contractor shall give precedence to the narrative
and revise the numerical code accordingly. Contractors are not required
to make this comparison on every claim. Precedence should be given
to the narrative code in those cases where a difference is identified
as the result of editing, prepayment review, or other action that
would identify a discrepancy. If an adjustment is subsequently necessary
because the numerical code was, in fact, correct, the adjustment
should be submitted with a reason for the adjustment code indicating
that there was no contractor error.
3.2.2.2.2 It is the hospital’s responsibility
to submit the information necessary for the contractor to assign
a discharge to a DRG.
3.2.2.2.3 When the discharge data is
inadequate (i.e., the contractor is unable to assign a DRG based
on the submitted data), the contractor is to develop the claim for
the additional information.
3.2.2.2.4 In some cases the “admitting
diagnosis” may be different from the principal diagnosis.
3.2.2.2.5 For neonatal claims only (other
than normal newborns), the following rules apply.
• If a neonate (patient age 0
- 28 days at admission) is premature, the appropriate prematurity diagnosis
code must be used as a principal or secondary diagnosis.
• Where a prematurity diagnosis
code is used, a fifth digit value of 0 through 9 must be used in
the principal or secondary diagnosis to specify the birth weight.
If no fifth digit is used, the Grouper will ignore that diagnosis
code and the claim will be denied.
• If a neonate is not premature,
a prematurity diagnosis code must not be used. The Grouper will automatically
assign a birth weight of “> 2,499 grams” and assign the appropriate
PM-DRG. If the birth weight is less than 2,500 grams, the birth
weight must be provided in the “remarks” section of the CMS 1450
UB-04.
• If there is more than one birth
weight on the claim, the Grouper will assign the claim to the “ungroupable”
DRG, and the claim will be denied.
• All claims for beneficiaries
less than 29 days old upon admission (other than normal newborns)
will be assigned to a PM-DRG, except those classified to DRGs 103,
480, 495, 512, and 513. DRGs for these descriptions can be found
at
http://www.health.mil/rates.
3.2.2.3 Each discharge will be assigned
to only one DRG (related, except as provided in
paragraphs 3.2.2.4 and
3.2.2.5,
to the patient’s principal diagnosis) regardless of the number of
conditions treated or services furnished during the patient’s stay.
3.2.2.4 When
the discharge data submitted by a hospital show a surgical procedure
unrelated to a patient’s principal diagnosis, the contractor shall
develop the claim to assure that the data is not the result of miscoding
by either the contractor or the hospital. Where the procedure and
medical condition are supported by the services and the procedure
is unrelated to the principal diagnosis, the claim shall be assigned
to the DRG, Unrelated OR Procedure.
3.2.2.5 When
the discharge data submitted by a hospital results in assignment
of a DRG which may need to be reviewed for coverage (e.g., abortion
without dilation and curettage, which does not meet the TRICARE
requirements for coverage), the contractor is to review the claim
to determine if other diagnoses or procedures which were rendered
concurrently are covered. If other covered services were rendered,
the contractor shall change the principal diagnosis to the most
logical alternative covered diagnosis, delete the abortion diagnosis
and procedure from the claim so that it does not result in a more
complex DRG, and regroup the claim.
Example: If a claim is grouped into the
DRG for an abortion and the abortion is not covered, but a female tubal sterilization was
performed concurrently, the contractor should change the principal
diagnosis to that for the tubal and delete the abortion from the procedures
performed. If no covered services were rendered, the claim must
be denied, and all related ancillary and professional services which
are submitted separately must also be denied.
3.2.2.5.1 Contractors are not normally
required to review all diagnoses and procedures to determine their
coverage. Contractors are required to develop for medical necessity
only if the principal diagnosis is generally not covered but potentially
could be. Deletion of a diagnosis and/or procedure is required only
when the principal diagnosis or procedure is not covered.
3.2.2.5.2 The only exception to the above
paragraph is for abortions. Since abortions are statutorily excluded
from coverage except for pregnancies resulting from rape, incest
or if the life of the mother is endangered, the contractor is to
ensure that payment is not affected by a noncovered abortion diagnosis
or procedure whether it is principal or secondary. In all cases
where payment would be affected, the abortion data is to be deleted
from the claim.