CBCS Outpatient and Inpatient Coding 1 — Questions and Answers
Question 1: What guidelines govern the selection of the principal diagnosis in inpatient coding?
- ICD-10-CM Outpatient Guidelines
- UHDDS (Uniform Hospital Discharge Data Set) definitions (Correct answer)
- CMS-1450 claim form instructions
- CPT surgery section guidelines
Correct answer: UHDDS (Uniform Hospital Discharge Data Set) definitions
The UHDDS (Uniform Hospital Discharge Data Set) defines the principal diagnosis and guides inpatient diagnosis code selection.
The Uniform Hospital Discharge Data Set (UHDDS) provides the definitions used for inpatient coding, including the definition of principal diagnosis: 'that condition established after study to be chiefly responsible for occasioning the admission of the patient to the hospital for care.' The UHDDS definitions are incorporated into the ICD-10-CM Official Guidelines for Coding and Reporting and apply to all inpatient encounters.
Question 2: What does 'present on admission' (POA) indicate?
- A condition that was diagnosed after the patient was admitted
- A condition that was present at the time the order for inpatient admission occurred (Correct answer)
- A complication that developed during surgery
- A condition documented only in the discharge summary
Correct answer: A condition that was present at the time the order for inpatient admission occurred
POA means the condition existed at the time the patient was admitted, not one that developed during the hospital stay.
Present on Admission (POA) is a condition that was present at the time of the order for inpatient admission. POA reporting is required by Medicare and many other payers for inpatient admissions. POA status affects hospital-acquired condition (HAC) payment penalties — if a complication or condition (like a pressure ulcer or surgical infection) is not POA and develops during the hospitalization, it may be designated as a hospital-acquired condition and can affect reimbursement.
Question 3: In the inpatient setting, what is a Diagnosis Related Group (DRG)?
- A system that classifies outpatient procedures for reimbursement
- A classification of inpatient diagnoses into groups that predict similar resource use for Medicare payment (Correct answer)
- A coding guideline for grouping multiple diagnoses on a claim
- A quality measure used by hospitals for accreditation
Correct answer: A classification of inpatient diagnoses into groups that predict similar resource use for Medicare payment
DRGs are a patient classification system used by Medicare to determine inpatient hospital reimbursement, grouping patients with similar diagnoses and expected resource use.
Diagnosis Related Groups (DRGs) were developed by CMS as the basis for the Medicare Inpatient Prospective Payment System (IPPS). Each DRG represents a group of patients with similar clinical characteristics and expected resource consumption. The hospital receives a fixed payment based on the assigned DRG regardless of actual costs incurred. The MS-DRG (Medicare Severity DRG) system further refines DRGs based on the presence of complications and comorbidities (CC) or major complications and comorbidities (MCC).
Question 4: What is the key coding difference between inpatient and outpatient settings for uncertain diagnoses?
- Both settings prohibit coding uncertain diagnoses
- Inpatient allows coding uncertain diagnoses as if confirmed; outpatient requires coding only signs and symptoms (Correct answer)
- Outpatient allows coding uncertain diagnoses; inpatient does not
- Both settings allow coding uncertain diagnoses with a modifier
Correct answer: Inpatient allows coding uncertain diagnoses as if confirmed; outpatient requires coding only signs and symptoms
In inpatient coding, 'probable,' 'suspected,' and 'likely' diagnoses may be coded as confirmed. In outpatient coding, only confirmed diagnoses or signs/symptoms are coded.
This is one of the most important differences between inpatient and outpatient coding. For inpatient encounters, ICD-10-CM guidelines allow coders to code diagnoses documented as 'probable,' 'suspected,' 'likely,' 'questionable,' or 'still to be ruled out' as if established, because the physician has done workup and has a strong clinical impression. For outpatient coding, only confirmed diagnoses may be coded; otherwise, signs, symptoms, and findings are coded.
Question 5: In MS-DRG assignment, what is the difference between a CC and an MCC?
- CC means the condition was the primary diagnosis; MCC means it was a secondary diagnosis
- CCs are complications/comorbidities that moderately affect resource use; MCCs severely affect resource use and result in higher payment (Correct answer)
- CC refers to surgical complications; MCC refers to medical complications
- CCs require additional documentation; MCCs do not
Correct answer: CCs are complications/comorbidities that moderately affect resource use; MCCs severely affect resource use and result in higher payment
MCCs (Major Complications and Comorbidities) are more severe conditions that significantly increase resource use and result in higher DRG payment; CCs have a moderate effect.
In the MS-DRG system, each DRG may have up to three variants based on the presence of complications and comorbidities: with MCC (major complications and comorbidities), with CC (complications and comorbidities), and without CC/MCC. MCCs are conditions that, when present as a secondary diagnosis, result in the most significant increase in resources used, while CCs represent conditions with a moderate increase. The assignment of MCC vs. CC significantly affects hospital reimbursement.
Question 6: What is the Ambulatory Payment Classification (APC) system used for?
- Inpatient hospital reimbursement under Medicare
- Outpatient hospital reimbursement under Medicare's Outpatient Prospective Payment System (OPPS) (Correct answer)
- Physician office visit reimbursement
- Long-term care facility reimbursement
Correct answer: Outpatient hospital reimbursement under Medicare's Outpatient Prospective Payment System (OPPS)
APCs are the classification and payment system CMS uses for outpatient hospital services under the Outpatient Prospective Payment System (OPPS).
Ambulatory Payment Classifications (APCs) are the basis for Medicare's Outpatient Prospective Payment System (OPPS). Similar to DRGs for inpatient care, APCs group outpatient services with similar clinical characteristics and resource use into payment groups. Unlike DRGs (where one payment covers the entire admission), multiple APCs can be assigned for a single outpatient encounter based on the services provided.
Question 7: What is the 'principal procedure' in inpatient coding?
- The most complex surgical procedure performed during the hospitalization
- The procedure performed for definitive treatment of the principal diagnosis or for complications of the principal diagnosis (Correct answer)
- The first procedure performed after admission
- The procedure with the highest relative weight in the DRG grouper
Correct answer: The procedure performed for definitive treatment of the principal diagnosis or for complications of the principal diagnosis
The principal procedure is the one performed for definitive treatment of the principal diagnosis, not necessarily the most complex or the first one performed.
Per UHDDS definitions, the principal procedure is the procedure performed for definitive treatment rather than one performed for diagnostic or exploratory purposes, or one necessary to take care of a complication. When two procedures appear to be principal, the one most closely related to the principal diagnosis is designated as the principal procedure. In ICD-10-PCS coding for inpatient procedures, the principal procedure significantly affects DRG assignment.
Question 8: In outpatient coding under OPPS, what is a 'packaged service'?
- A bundled payment for a group of unrelated services
- A service whose payment is included in the APC payment for the primary service (Correct answer)
- A service that requires separate billing under its own APC
- A service covered only under the inpatient benefit
Correct answer: A service whose payment is included in the APC payment for the primary service
Packaged services are those whose costs are considered bundled into the APC payment for the primary or adjunctive service and are not paid separately.
Under OPPS, CMS packages certain items and services into the APC payment for the primary service, meaning they are not paid separately. Packaged services include items like routine supplies, recovery room services, and certain ancillary services that are integral to the procedure. The packaging concept is similar to CPT's bundling concept and is designed to create a more comprehensive payment that accounts for the total cost of providing a service.
CBCS Outpatient and Inpatient Coding 1
What guidelines govern the selection of the principal diagnosis in inpatient coding?