Free Practice Questions for ACDIS CCDS Exam

An MCC—major complication or comorbidity—represents the highest secondary-diagnosis severity category within the standard three-tier MS-DRG hierarchy. CMS describes MCCs as diagnoses with the highest level of severity affecting hospital resource use, CCs as conditions with a moderate level, and non-CC diagnoses as the lowest severity level.

When an MS-DRG family is divided into “with MCC,” “with CC,” and “without CC/MCC,” the presence of a qualifying MCC generally moves the case into the highest severity subdivision, assuming no exclusion or other grouper rule prevents that effect.

This does not mean every MCC always increases payment. Some secondary diagnoses are excluded as MCCs or CCs in particular circumstances because of principal-diagnosis exclusions or DRG-specific logic. CMS's FY 2026 Definitions Manual specifically contains exclusion lists and severity logic for such situations.

CDI specialists should understand MCC/CC logic to interpret working DRGs, but query activity must be driven by clinical accuracy rather than the financial value of a severity level.

CCDS Reference Topics: MS-DRGs; MCC; CC; severity subdivisions; resource utilization; reimbursement compliance.

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The appropriate action is to query for clarification. A temporal relationship—anemia occurring after surgery—does not automatically establish that a reportable complication occurred. Likewise, a CDI specialist cannot independently translate a substantial hemoglobin decline into acute posthemorrhagic anemia without provider documentation.

The FY 2026 Official Guidelines state that complication-of-care code assignment depends on provider documentation establishing the relationship between the condition and the care or procedure unless the classification specifically instructs otherwise. They also emphasize that not every condition occurring during or following medical care is a complication.

The query could present the preoperative and postoperative hemoglobin values, estimated blood loss, transfusions, clinical monitoring, and treatment. Appropriate response options might include acute blood loss anemia, expected postoperative anemia, another diagnosis, or clinically unable to determine, depending on the record.

Option A overstates causation. Option B independently diagnoses the patient from laboratory findings. Option D is equally inappropriate because clinically significant postoperative anemia may be reportable.

CCDS Reference Topics: Complications of care; postoperative anemia; clinical indicators; cause-and-effect clarification; compliant querying.

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A significant mismatch rate should trigger structured CDI/coding reconciliation, not an assumption that either department is wrong.

Working MS-DRGs are provisional. Final coding may change because of discharge-summary diagnoses, operative reports, pathology results, late physician clarification, Coding Clinic guidance, sequencing conventions, final procedure coding, CC/MCC exclusions, or other grouper logic unavailable during the concurrent CDI review.

The manager should categorize mismatch causes. Useful categories include principal-diagnosis differences, missed secondary diagnoses, procedure-code differences, coding-guideline interpretation, query results, discharge documentation, and technical grouper issues.

Patterns can then identify whether education is needed for CDI specialists, coding professionals, physicians, or multiple groups.

Requiring coding staff to adopt the CDI working DRG would undermine coding independence and final coding accountability. Excluding mismatches from metrics would conceal an important quality indicator.

CMS confirms that the FY 2026 MS-DRG Definitions Manual contains the complete grouper logic for Version 43.1, making current grouper rules essential when evaluating discrepancies.

CCDS Reference Topics: MS-DRG reconciliation; CDI/coder agreement; program analysis; education; grouper logic.

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The most appropriate clarification concerns the underlying cause/type of pneumonia. The record documents “HCAP,” but that term does not identify a specific causative organism or pathophysiologic pneumonia type. The patient is being actively treated with antibiotics, has leukocytosis, and was admitted with pneumonia-related documentation, creating a legitimate opportunity to clarify clinically supported specificity.

The other options are weaker. Hemoglobin of 9.0 supports anemia but does not establish acute blood loss anemia without evidence of active/recent blood loss or an acute decline. Sodium of 134 mEq/L is only mildly reduced and, without treatment or other clinical significance, does not by itself justify seeking a diagnosis solely from the laboratory value.

The record already specifies diastolic heart failure. Although acuity could sometimes warrant clarification, the presented findings do not strongly establish acute decompensated heart failure: oxygen requirement is modest, saturation is 98%, and no pulmonary edema, diuretic escalation, or other acute HF indicators are provided.

The query should remain neutral and allow the provider to identify the pneumonia type only if clinically determinable.

CCDS Reference Topics: Pneumonia specificity; clinical indicators; documentation clarification; query prioritization.

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This patient has sepsis with documented acute organ dysfunction, specifically acute respiratory failure and acute renal failure. Under ICD-10-CM coding guidance, sepsis associated with acute organ dysfunction is classified as severe sepsis when the provider establishes the relationship between the systemic infection and the organ dysfunction.

The documentation specifically states that respiratory failure and acute renal failure are secondary to sepsis caused by pneumonia. That causal linkage is critical. FY 2026 Official Guidelines require the underlying systemic infection code, followed by a code from R65.2- for severe sepsis, plus additional codes identifying each associated acute organ dysfunction.

Septic shock is not supported because the scenario does not document circulatory failure attributable to sepsis, persistent hypotension requiring vasopressors, or a provider diagnosis of septic shock. “Septicemia” is also not equivalent terminology for coding sepsis and is not the appropriate classification here.

From a CDI perspective, the defining feature is not simply that the patient is critically ill. It is the documented relationship between sepsis and acute organ dysfunction.

CCDS Reference Topics: Sepsis; severe sepsis; acute organ dysfunction; sequencing guidelines.

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Severe protein-calorie malnutrition is the correct answer. This question is adapted from an official CCDS sample question published by ACDIS.

Under the FY 2026 MS-DRG Definitions Manual, E43, unspecified severe protein-calorie malnutrition, is classified as an MCC. In contrast, moderate and mild protein-calorie malnutrition codes are classified as CCs rather than MCCs.

An MCC can materially affect MS-DRG assignment when the applicable DRG family differentiates cases by MCC status and when no exclusion or other grouper rule prevents the effect. However, the financial effect is never sufficient justification for a query. Documentation must be clinically supported and reflect the patient's actual condition.

A dietitian may document detailed nutrition findings and malnutrition criteria, but the reportable diagnosis ordinarily requires documentation by the provider responsible for establishing diagnoses. Therefore, when strong nutritional indicators exist but the provider has not documented malnutrition, a compliant query may be appropriate.

For CCDS preparation, candidates should understand both the clinical characteristics of malnutrition and its coding/reimbursement classification.

CCDS Reference Topics: MCCs; malnutrition; MS-DRG methodology; documentation requirements; IPPS.

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ICD-10-CM permits the NIH Stroke Scale score to be reported from documentation by an appropriate clinician other than the provider responsible for establishing the diagnosis. The underlying stroke diagnosis itself must be appropriately documented by the provider.

This is similar to other specified exceptions such as BMI, pressure-ulcer stage, coma scale values, and certain additional clinical elements for which qualified non-provider documentation may support code assignment.

The exception does not mean that a stroke nurse can independently establish cerebral infarction for coding. Rather, once the provider has documented the stroke, the nurse's formal NIHSS assessment can supply the standardized severity measurement.

This approach recognizes that specially trained clinical professionals routinely collect and document these structured measurements as part of patient care.

If multiple NIHSS values are documented, the applicable coding instructions and timing requirements should be followed rather than simply selecting the highest score because it produces a different code.

For CDI professionals, awareness of these non-provider documentation exceptions prevents unnecessary physician queries while ensuring that important severity information is not lost.

CCDS Reference Topics: NIH Stroke Scale; cerebral infarction; non-provider documentation; coding exceptions; stroke severity.

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The record contains a significant clinical-documentation discrepancy. A TIA is characterized by transient neurologic dysfunction without acute infarction, whereas this patient's MRI demonstrates an acute cerebral infarction and the patient continues to have a persistent focal neurologic deficit.

Therefore, the provider should be asked to clarify the final diagnosis.

The CDI specialist cannot independently replace TIA with cerebral infarction, even though the clinical findings strongly favor an infarction. Provider documentation must reconcile the diagnostic evidence.

Automatically reporting both conditions could also misrepresent the encounter when one diagnosis has effectively been superseded by subsequent findings.

The query should objectively present the initial TIA documentation, MRI-confirmed infarction, persistent right-sided weakness, and resolution of aphasia, then ask the physician to clarify the final neurologic diagnosis.

This scenario illustrates why concurrent CDI review must continue beyond initial admission documentation. Early diagnoses may evolve as diagnostic testing becomes available.

Accurate stroke documentation affects principal diagnosis, severity representation, rehabilitation planning, risk adjustment, quality reporting, and longitudinal patient history.

CCDS Reference Topics: Cerebral infarction; TIA; imaging; conflicting documentation; diagnostic evolution.

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An unanswered clinically significant query should be managed through the organization's defined escalation process. The process may involve CDI leadership, coding leadership, a physician advisor, department leadership, or other designated personnel, depending on organizational policy.

Neither CDI nor coding may independently supply the missing diagnosis because diagnostic conclusions remain the provider's responsibility. Removing an unresolved query simply to accelerate billing can undermine documentation integrity and may create compliance problems.

Escalation policies should be standardized rather than applied only when a particular diagnosis affects reimbursement. Policies commonly address expected response time, reminder intervals, responsible escalation personnel, high-priority queries, retrospective queries, and final-bill procedures.

The 2026 ACDIS/AHIMA Guidelines for Achieving a Compliant Query Practice supersede prior versions and serve as the current foundational guidance for organizations establishing compliant query policies and procedures.

A mature escalation process balances timely claim completion with respect for provider workload and independent clinical judgment. Its purpose is obtaining complete and accurate documentation, not forcing agreement with a CDI-generated diagnosis.

CCDS Reference Topics: Query escalation; organizational policy; unanswered queries; compliance; provider responsibility.

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Acute on chronic systolic heart failure is the intended answer. This scenario is adapted from an official ACDIS CCDS sample question, which uses dyspnea, edema, elevated BNP, reduced ejection fraction, and left-ventricular dysfunction to test appropriate heart-failure clarification.

The ejection fraction of 25% and documented left ventricular systolic dysfunction support a systolic phenotype. The patient's significant dyspnea and edema are consistent with acute decompensation superimposed on the established history of heart failure. Together, these findings create a legitimate opportunity to clarify type and acuity.

The CDI specialist must nevertheless avoid diagnosing acute-on-chronic systolic failure independently. The provider determines whether the findings represent acute decompensation, chronic disease, another heart-failure phenotype, or another explanation entirely.

Option A would require evidence supporting both systolic and diastolic dysfunction. Option B fails to capture the apparent acute decompensation. Option D conflicts with the documented systolic dysfunction and reduced EF.

This question illustrates a frequent CCDS theme: translating clinical indicators into a neutral clarification opportunity rather than assigning a diagnosis based solely on test results.

CCDS Reference Topics: Heart-failure acuity and type; ejection fraction; BNP; compliant query development.

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