2.3 Secondary Diagnosis Reporting Standards & POA Status
Key Takeaways
Report clinically significant additional diagnoses under Section III before assigning their POA indicators; timing does not establish reportability.
The five additional-diagnosis criteria concern evaluation, treatment, diagnostic procedures, extended stay, or increased nursing care/monitoring.
POA is determined at the inpatient admission order; a condition developing during prior outpatient care can be Y.
U denotes insufficient timing documentation, W denotes clinical indeterminacy, and exempt codes follow the applicable fiscal-year list and claim-format instructions.
The selected HAC payment restriction and hospital-level HACRP are distinct; a POA indicator alone does not establish a DRG, payment amount, or quality outcome.
Separate reportability, admission timing, and payment
For an inpatient record, three questions must be answered separately: Is the condition reportable? Was it present on admission? What effect, if any, does the complete claim have under the applicable grouper and payment rules? A diagnosis can be reportable without changing a DRG, and a condition that develops after admission is not automatically a preventable adverse event.
The FY2027 ICD-10-CM Official Guidelines, Section III and Appendix I, provide the additional-diagnosis and present-on-admission framework. Assign the diagnosis codes under the reporting rules first, then assign the applicable present on admission (POA) indicators. POA does not make an otherwise unreportable condition reportable.
Additional diagnoses must affect care
Section III describes clinically significant additional conditions affecting care through at least one of five criteria:
| Criterion | Example with a documented diagnosis | What the reviewer verifies |
|---|---|---|
| Clinical evaluation | A provider evaluates and documents a new encephalopathy during a pneumonia admission | The clinical assessment and established diagnosis, rather than confusion alone |
| Therapeutic treatment | Provider-documented hypokalemia is treated with replacement | The diagnosis and treatment relationship, rather than a laboratory value alone |
| Diagnostic procedures | Additional testing evaluates a documented concurrent condition | The condition's significance and the purpose of the workup |
| Extended stay | Discharge is delayed to manage a documented glycemic problem | The condition's actual effect on the current stay |
| Increased nursing care or monitoring | A documented condition requires additional monitoring | The link between the condition and care beyond routine services |
One applicable criterion is sufficient; the patient does not need all five. A chronic diagnosis may qualify through continued treatment or monitoring during the stay. Do not exclude it merely because it is stable. Equally, a historical problem-list entry alone does not prove that the condition affected current care.
Section III.B addresses abnormal findings. Laboratory, imaging, and pathology findings are not reported as inpatient diagnoses unless the provider indicates their clinical significance. An incidental simple renal cyst appearing only in a radiology report, without relevant provider assessment or care, does not become a secondary diagnosis merely because the reviewer can find a code for it. If a finding prompts further evaluation or treatment but its significance is unclear, clarification may be appropriate.
Resolved conditions from an earlier episode that have no bearing on the current stay should not be represented as active current diseases. A history code can be appropriate when the history affects current care or treatment. Distinguish that from a condition treated during this admission that has resolved by discharge; resolution during the stay does not erase the care it required.
Use documentation sources allowed by the guidelines. Section I.B.14 permits specified details, such as pressure-ulcer stage, to come from other clinicians, while requiring the associated diagnosis from the patient's provider. Such exceptions do not authorize the CDI reviewer to independently diagnose every condition from nursing observations or test results.
POA uses the inpatient admission boundary
Appendix I defines POA relative to the time of the inpatient admission order. A condition developing during an emergency, observation, or outpatient-surgery encounter before that order is considered present on admission. Physical arrival at the hospital and inpatient admission are different boundaries.
The reporting requirements apply to claims and facilities subject to the applicable POA mandate; do not assume every hospital service is an IPPS claim. Within the reporting framework, review principal and additional diagnoses and applicable external-cause codes, using the current exemption list.
| Indicator | Meaning | Distinction to preserve |
|---|---|---|
| Y | Present at inpatient admission | Diagnosis can be confirmed later when it was clearly present at admission |
| N | Not present at inpatient admission | Does not by itself establish negligence or a selected HAC payment adjustment |
| U | Documentation insufficient to determine timing | Unclear documentation; use only in limited circumstances and seek clarification when appropriate |
| W | Provider cannot clinically determine timing | Clinical indeterminacy, rather than simply a missing entry |
| Exempt | Code is on the applicable POA-exempt list | Appendix I directs leaving the field blank for exempt codes; CMS's coding table also identifies 1 as the exempt/unreported value |
Follow current claim-format instructions for transmitting exempt information. E is not an additional POA reporting option in these sources. Consult the fiscal-year exemption list rather than applying a blanket rule to all Z codes, congenital conditions, or external-cause codes.
Timing is not the date the diagnosis was written
There is no requirement that the provider identify or document POA within a fixed number of hours. A diagnosis recognized on day four can be Y when the condition clearly existed at admission. Conversely, a diagnosis entered on day one can be N if it actually developed after the inpatient order.
Suppose a provider confirms an infection after culture results return several days into the stay. Review the admission findings and provider judgment about whether the infection existed then; do not use the culture-result date alone. If the provider explicitly cannot clinically determine onset, W may apply. If the record merely lacks sufficient timing documentation, that is the U-versus-clarification issue, not automatic W.
Codes containing multiple clinical concepts require their specific Appendix I instructions. If one code represents both a chronic condition and an acute exacerbation, do not assign Y solely because the chronic component existed before admission. Generally, all included clinical concepts must have been POA for Y; an exacerbation that begins after admission can make the combined code N. The appendix has specific guidance for infection codes whose causal organism is identified later.
These distinctions make a focused POA clarification useful: establish onset from the patient's clinical course and provider judgment without asking for the indicator that produces a desired payment result.
The selected HAC payment provision
CMS's Hospital-Acquired Conditions payment provision concerns selected conditions under Section 5001(c) of the Deficit Reduction Act. POA reporting began for applicable discharges on October 1, 2007; the selected-condition payment effects began October 1, 2008.
For applicable selected HACs reported as N or U, the condition does not produce the additional payment based on its CC/MCC effect. Y and W do not trigger that POA-based restriction. This does not mean every Y or W diagnosis is a CC/MCC, or that every N diagnosis loses its severity effect. Consult the actual fiscal-year HAC list and any required diagnosis/procedure combination. The CMS coding page explains the indicator distinctions.
The diagnosis remains reportable when it meets reporting criteria. Do not delete a complication from the claim simply because its payment effect is restricted. Coding should accurately represent the encounter.
Consider a patient admitted for heart failure who sustains a new fracture after an inpatient fall and receives surgical repair. The timing supports N for the newly developed fracture. Selection under the HAC rules requires the exact applicable codes. Even when a selected-HAC restriction applies, the complete grouping analysis must include the repair procedure and other claim inputs. The MS-DRG Version 44 defining manual explains procedure-dependent and unrelated-operating-room pathways. Do not promise that the claim remains in its original medical DRG or that all additional care receives zero payment.
HACRP is a different program
The Hospital-Acquired Condition Reduction Program (HACRP) evaluates hospital-level performance using specified patient-safety and healthcare-associated-infection measures. CMS reduces payments by 1% for subsection (d) hospitals with Total HAC Scores greater than the 75th percentile; the adjustment applies to Medicare fee-for-service discharges in the corresponding fiscal year.
That hospital-level calculation is distinct from suppressing a selected diagnosis's payment effect on an individual claim. A code on the DRA HAC list is not automatically a HACRP measure event, and a POA edit does not guarantee a better hospital score. Each measure has its own population, exclusions, timing, and data source. CDI should support accurate documentation and collaborate with coding and quality staff using the appropriate program specifications.
Close a review by documenting all three decisions: the reporting basis, the supported POA indicator or exemption, and any separately verified payment or quality implication. This keeps a correct timing conclusion from being stretched into an unsupported financial or safety conclusion.
Which scenario lacks the documented basis to report the condition as an additional diagnosis on the stated acute inpatient claim?
An incidental renal cyst has no provider assessment of significance or related care.
Provider-documented hypertension is treated with continued antihypertensive medication during the stay.
Provider-documented hypokalemia is treated with potassium replacement and follow-up monitoring.
Provider-documented COPD requires continued maintenance respiratory treatment during the stay.
The provider confirms a catheter-associated urinary tract infection and explicitly documents that its onset relative to inpatient admission cannot be clinically determined. The relevant code is not POA-exempt, and there is no conflicting documentation. Which POA indicator fits?
Y, because transfer with a catheter proves the infection was present before admission.
N, because the infection was first named in a progress note after admission.
U, because all uncertain onset determinations represent insufficient documentation.
W, because the provider states that onset cannot be clinically determined.
An applicable Medicare inpatient claim includes a reportable fracture acquired after an inpatient fall and a repair procedure. The exact diagnosis/procedure combination has been verified as subject to the selected HAC payment rule, and POA is N. Which conclusion is justified?
Retain the reportable diagnosis, apply the selected-HAC restriction, and regroup the complete claim.
Delete the fracture diagnosis because a selected HAC with POA N is never reportable.
Make the fracture principal automatically because the repair was an operating-room procedure.
Keep the original medical DRG without regrouping because the HAC rule requires ignoring every procedure related to the fracture.
Sections you finish are checked off in the contents.