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 tubal ligation 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.