A DRG (Diagnosis Related Group) is a classification that groups hospital inpatient stays with similar diagnoses, procedures, and resource use so that Medicare and other payers can pay a fixed amount per stay. Medicare uses MS-DRGs (Medicare Severity DRGs), and the codes a coder assigns determine which DRG the stay falls into.
Understanding DRGs in Medical Coding
What is a DRG?
A Diagnosis-Related Group (DRG) is a system that classifies hospital cases into groups expected to have similar hospital resource use. The United States primarily uses DRGs for Medicare and Medicaid reimbursement, but various healthcare systems around the world have also adopted them. The system aims to ensure that hospitals receive compensation for the complexity and intensity of the services they provide.
Outliers
In the context of DRGs, outliers are cases that significantly deviate from the standard DRG payment structure due to unusually high costs. Medicare decides outlier status when it prices the claim. Specifically, a case qualifies when its costs exceed the DRG payment plus a fixed-loss threshold. Outlier payments aim to protect hospitals from financial losses on these complex cases. For example, if a patient needs far more costly care than typical for their DRG, the hospital may receive an outlier payment that covers part of the extra cost.
Groupers
Groupers are software tools that assign a DRG to a patient’s hospital stay based on specific data input. Specifically, this includes the principal diagnosis, secondary diagnoses, procedures performed, and patient demographics. Groupers then analyze this information against the DRG classification system to determine the appropriate DRG assignment, ensuring standardized coding and reimbursement processes.
Steps to Determine DRG
- Data Collection: Gather all relevant patient data, including the principal diagnosis, secondary diagnoses, and any procedures performed during the hospital stay.
- Coding: Use the International Classification of Diseases (ICD) coding system to accurately code diagnoses and procedures. This step is especially crucial for correct DRG assignment.
- Input Data into Grouper: Enter the coded data into the grouper software. Then, the grouper will analyze the information against its database.
- DRG Assignment: The grouper assigns a DRG based on the information provided. The grouper assigns only the DRG. However, outlier status comes later, when the payer prices the claim.
- Review: Verify the assigned DRG for accuracy, ensuring that staff entered and coded all data correctly.
- Documentation: Maintain thorough documentation of the coding process, decisions made, and the rationale for the assigned DRG.
DRG Assignment Process
The DRG assignment process involves several components:
- Principal Diagnosis: The main reason for the patient’s hospital stay. This diagnosis drives the DRG assignment.
- Secondary Diagnoses: Additional conditions that affect patient management or treatment. These can also impact the DRG, especially when they qualify as a CC or MCC.
- Procedures: Any surgeries or other significant procedures performed during the stay. They can also influence the DRG category.
- Comorbidities and Complications: These factors can elevate the DRG assignment if they increase resource use or complexity.
- Patient Demographics: Age, sex, and other demographic factors may also influence the DRG assignment.
Once the grouper assigns the DRG, it is essential for healthcare providers to regularly review their coding practices, ensuring accuracy and compliance with regulations. Incorrect coding can lead to significant financial repercussions for healthcare facilities, including underpayments or audits.
In summary, understanding DRGs, outliers, groupers, and the assignment process is vital for accurate medical coding and reimbursement. By following a structured approach to coding and documentation, healthcare providers can navigate the complexities of DRG systems effectively, ensuring fair compensation for the services they provide. Proper DRG assignment not only affects financial outcomes but also reflects the quality of care delivered to patients.
What Determines the MS-DRG?
- The principal diagnosis (ICD-10-CM)
- Secondary diagnoses that qualify as a CC (complication or comorbidity) or MCC (major complication or comorbidity)
- Procedures performed (ICD-10-PCS)
- Patient age, sex, and discharge status
Many MS-DRGs come in groups of three: with MCC, with CC, and without CC or MCC. Therefore, documenting and coding a qualifying condition can move a case to a higher weighted DRG. Learn more about MCCs in medical coding and Present on Admission indicators.
MS-DRG vs APR-DRG
Medicare uses MS-DRGs for inpatient payment. APR-DRGs (All Patient Refined DRGs) add severity of illness and risk of mortality subclasses. Many state Medicaid programs use them, and they also support quality reporting.
How Coders Affect the DRG
Inpatient coders select the principal diagnosis, capture every reportable CC and MCC the documentation supports, code procedures in ICD-10-PCS, and send queries to providers when documentation is unclear. Overall, accurate DRG assignment protects hospital revenue and keeps claims compliant. See our inpatient coding guidelines.
DRG FAQs
What does DRG stand for?
Diagnosis Related Group.
Who uses DRGs?
Medicare uses MS-DRGs to pay hospitals for inpatient stays under the Inpatient Prospective Payment System. Many Medicaid programs and commercial payers also use DRG based payment.
Are DRGs used for outpatient claims?
No. DRGs apply to inpatient hospital stays. Instead, Medicare pays hospital outpatient services under APCs.
What is a CC and an MCC?
A CC is a complication or comorbidity and an MCC is a major complication or comorbidity. Both are secondary diagnoses that can increase the DRG weight.