Sepsis Documentation and Coding is critical in inpatient medical coding because it may often present with multiple clinical conditions, several different diagnosis codes and have a major impact on the diagnosis related group (DRG) code. There are localized infections, acute organ dysfunction and septic shock that can all lead to sepsis, and each case of sepsis should be reviewed in the medical record. The problem for coders and clinical documentation improvement (CDI) practitioners are not just knowing when blood work is abnormal or that there is an infection present. Coding should be according to provider’s documented diagnosis and the ICD-10-CM sepsis coding guidelines. Complete and consistent provider documentation is a key factor in correct code assignment as stated by the Official Guidelines for ICD-10-CM [1].
Coders and clinical documentation improvement (CDI) specialists can use clinical indicators such as fever, low body temperature, rapid heart rate, rapid breathing, abnormal white blood cell counts, elevated lactate levels, low blood pressure, altered mental status, positive cultures, and organ dysfunction to identify cases that may require further review. These findings, however, are not alone enough to sepsis principal diagnosis. Many different conditions can cause abnormal vital signs or abnormal lab results in a patient. For instance, high heart rates may be caused by dehydration, pain, fever, or side effects of some medicines. Final diagnosis and coding guidelines must be supported with healthcare provider documentation, such as progress notes, labs, admission data, treatment, imaging data and discharge summary [2].
The most significant difference between ICD-10-CM sepsis coding is that the patient has a localized infection or sepsis. Localized infection effects specific body site. These may include pneumonia, cellulitis, urinary tract infection or an infected wound. Sepsis is a systemic infection to which provider documentation required. In sepsis with a localized infection, the system infection will be sequenced first and the localized infection will be sequenced second in the sepsis sequencing guidelines.
One of the most frequent problems in sepsis cases is sequencing. If the infection is simple, the appropriate code for the underlying systemic infection is assigned. If it is not specified, then A41.9, Sepsis, unspecified organism, can also be used.
Severe sepsis needs to be coded with at least two codes; one for the underlying systemic infection and one from R65.2, Severe sepsis [3]. If an associated acute organ dysfunction, this should be identified using additional code(s). For instance, if a provider writes sepsis in the record, and the acute kidney injury was due to the sepsis, then the systemic infection code, severe sepsis code, and code for acute kidney injury should all be included in the record. It is crucial that there is a link between sepsis and organ dysfunction. If both acute organ dysfunction and severe sepsis are found in the record it does not necessarily indicate severe sepsis.
There are additional requirements for coding septic shock. Septic shock is defined as circulatory failure that occurs with severe sepsis and is a form of acute organ dysfunction. If there is a systemic infection, that should be sequenced first (for example, R65.20, Systemic infection), followed by R65.21, Severe sepsis with septic shock, unless any of the postprocedural septic shock guidelines apply. Septic shock coding cannot be the main diagnosis.
A sepsis physician query might be warranted if there is incomplete, conflicting or unclear documentation in the clinical record.
- There is strong clinical evidence that it is a systemic infection, and yet sepsis is not recorded.
- The provider records sepsis and does not specify information if available, which organism and/or underlying infection caused the sepsis.
- Both sepsis and an acute organ dysfunction have been reported and the connection between the two is not fully understood.
- Severe sepsis is documented in one part of the record but not consistently documented elsewhere.
- The term “urosepsis” is located in the record.
- Severe sepsis may have been present on admission, but the timing is unclear.
- Sometimes multiple providers may record conflicting diagnoses in a single record. In that case the coder or CDI specialist should initiate a query to clarify.
A good query must be substantiated by the clinical picture and it must not be leading. It is not used to force the provider to diagnose the problem. A record might include a diagnosis of sepsis and acute kidney injury without stating if the kidney injury was due to sepsis. The coder or the CDI specialist should not presume a link and should ask the provider. The guidelines explicitly state that the provider is to be inquired about when this relationship is not clear. Urosepsis is a non-specific term, not mixed with sepsis and does not have a default code so it need clarification from the provider [4].
There are common sepsis coding and sequencing mistakes that impact accuracy of sepsis coding.
1-Sepsis recoding: Coding sepsis using only the clinical indicators (provider diagnosis absent) or provider diagnosis (no documentation to support sequencing).
2-Inappropriate sequencing, reporting R65.20 or R65.21 as a first listed code or not sequencing the underlying infection code first.
3-Failure to include organ dysfunction codes in the severe sepsis diagnosis, which can underestimate a diagnosis’ severity and may impact DRG assignment.
4-Failure to query ambiguous terminology: Not asking for clarification of confusing words such as urosepsis or other words not classified for inclusion.
5-Misdiagnosing non-infectious origin for sepsis-related SIRS: Codes for sepsis, severe sepsis or septic shock should not be reported in conjunction with R65.10.
6-Inconsistently Assigned POA Indicator: Errors may occur with cases that have sepsis on admission and are documented at a later time within the hospital stay.
7-Postprocedural Sepsis: Sepsis due to postprocedural infections may be coded under different principal diagnosis and sequencing rules.
A significant number of sepsis-related diagnoses have an impact on DRG assignment. They can be a major complication/comorbidity (MCC) or a complication/comorbidity (CC) and they can also be the principal diagnosis that sets the base DRG. The DRG may not be valid unless the underlying infection is sequenced first, or the DRG may not indicate the true severity of the patient’s condition. An under-coding severity (such as missing organ dysfunction codes or not capturing septic shock), can move a case into the lower weighted sepsis DRG assignment and will also not reflect the level of resources consumed in the patient’s care, which will lead to less reimbursement. Compliance risk and audit exposure are the risk factors when over-coding or coding without supporting documentation for sepsis claims because these claims are subject to close review by payers and auditors [5].In addition to cost, inaccurate coding of sepsis can have a significant impact on hospital-level quality measures, such as mortality, readmission rates for sepsis-related conditions, and on a facility’s public reporting program rankings.
Case 1: Sepsis present on admission, as primary diagnosis. Patient presents with fever, tachycardia and history of “sepsis secondary to a urinary tract infection”. There is no record of any organ dysfunction. Rationale: There is no organ dysfunction with sepsis; therefore, if there is a separate code for the urinary tract infection, that one would be the principal diagnosis. There is no history of severe sepsis or septic shock, therefore there is no R65.2x code.
Rationale: Sepsis is a principal diagnosis and no organ dysfunction is present, therefore the underlying infection code is recorded first as the principal diagnosis and an additional code for the localized infection (urinary tract infection) is recorded as a localized or secondary diagnosis if separately documented. There is no R65.2x code because of no documentation of severe sepsis or septic shock.
Case 2: A patient who develops acute severe sepsis with septic shock post admission. A patient has been admitted with pneumonia. On the second day in hospital, the patient becomes hypotensive and needs vasopressor support, and develops acute kidney injury, which the doctor documents as “severe sepsis with septic shock secondary to pneumonia”. Rationale: The code for pneumonia is the main diagnosis in the absence of sepsis and the code for the underlying infection, septic shock, R65.21 is a secondary diagnosis and the acute kidney injury code is also a secondary diagnosis as the pneumonia code is the main diagnosis. For the sepsis-related codes, the POA indicator would be “N” for this complication occurred during the stay.
Rationale: Since the admission diagnosis was pneumonia, and sepsis was not present at admission, the diagnosis code for pneumonia could be the main diagnosis, with septic shock and the acute kidney injury as secondary diagnoses based on the clinical picture. Sepsis when not present on admission is coded as a secondary diagnosis. The rule for coding the system infection (sepsis) first does not apply in this situation since sepsis developed after admission. The POA indicator for the sepsis-related codes would be “N,” reflecting that this complication developed during the stay.
When documentation is incomplete, coders and CDI professionals need to ensure that sepsis and septic shock are documented accurately with clarity by answering queries quickly, and to ensure that they are sequenced correctly by ICD-10-CM Official Guidelines. Ensuring that the documentation and sequencing is correct will not only ensure that the patient’s clinical documentation is accurate, but the coding and reimbursement integrity of the facility will also be maintained.
1 https://pmc.ncbi.nlm.nih.gov/articles/PMC10701636/
2 https://www.aapc.com/blog/73594-conquer-coding-for-sepsis-and
sirs/?srsltid=AU7gw4W31ZgFIxiPxxbHIjkzbPaiWH5vQlh7eHYsRSmYJOXj8_DfS6pn
3 https://hiacode.com/blog/education/sepsis-series-sequencing-the-diagnosis-of-sepsis
4 https://medcodexhealth.com/blog/sepsis-clinical-indicators-and-documentation-icd-10-guide-2026
5 https://codingclarified.com/medical-coding-and-drgs/