To examine hospital coding practices using stroke-specific Diagnosis-Related Groups (DRGs) and assess variation based on hospital teaching status.

Hospitals use DRGs to classify admissions based on level of severity for the purpose of reimbursement – defined as with major complication or comorbidity (MCC), with complication or comorbidity (CC), or without CC/MCC – with escalating reimbursement for CC/MCC. Various hospital factors may contribute to differences in hospital-level billing.

We conducted a retrospective study of patients with ischemic and hemorrhagic stroke using the State Inpatient Databases (SID) from California, Florida, and New York (2018-2020). We analyzed variability in stroke-specific DRGs (Ischemic Stroke with thrombolytic agent DRG 61 [MCC] ,62 [CC], or 63 [w/o CC/MCC]; Intracranial Hemorrhage or Cerebral Infarction DRG 64 [MCC], 65 [CC], or 66 [w/o CC/MCC]) by hospital teaching status and assessed hospital charges.

For ischemic stroke with thrombolytic agent, individual hospitals coded MCC (DRG-61) between 20% (25^th percentile) and 34% (75^th percentile) of the time. For intracranial hemorrhage or cerebral infarction, hospitals coded MCC (DRG-64) between 28% (25^th percentile) and 40% (75^th percentile) of the time.

For ischemic stroke with thrombolytic agent, teaching hospitals coded MCC more frequently with MCC (DRG-61) median of 28% [IQR 20-34%], compared to non-teaching hospitals at median of 25% [IQR 18-33%]. For intracranial hemorrhage or cerebral infarction, teaching hospitals coded MCC more frequently with MCC (DRG-64) median of 36% [30-42%], compared to non-teaching hospitals at median of 30% [25-35%]. Median charges were $120,666 for DRG-61 compared to $86,221 for DRG-63, and $68,720 for DRG-64 compared to $41,253 for DRG-66.

This study reveals high variability in stroke coding practices, with 10 to 15 percentage point interquartile range in the frequency of MCC coding of stroke-related DRGs across comparable hospitals. These findings highlight the need to address non-clinical factors in reimbursement policies.