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R65.21 ICD-10-CM Code: Severe sepsis with septic shock

Compare with another codeCheck this code on a claim

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
1 Excludes1 · 8 use-additional codes · 9 code-first instructions
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 2

Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too; the Instructions section marks which is which.

Code firstSequence the underlying condition before this code
  • underlying infection, such as:
  • infection following a procedure (T81.4-)
  • infections following infusion, transfusion and therapeutic injection (T80.2-)
  • puerperal sepsis (O85)

+5 more in Instructions

Use additional codeReport with this code when documented
  • code to identify specific acute organ dysfunction, such as:
  • acute kidney failure (N17.-)
  • acute respiratory failure (J96.0-)
  • critical illness myopathy (G72.81)

+4 more in Instructions

Excludes1Never report with this code
  • postprocedural septic shock (T81.12-)

Most relevant related codes MedCoder-derived

Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.

CompareCheck ClaimView Related Codes

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v44, Appendix B.

  • MS-DRG 870 — SEPTICEMIA OR SEVERE SEPSIS WITH MV >96 HOURS (MDC 18)
  • MS-DRG 871 — SEPTICEMIA OR SEVERE SEPSIS WITHOUT MV >96 HOURS WITH MCC (MDC 18)
  • MS-DRG 872 — SEPTICEMIA OR SEVERE SEPSIS WITHOUT MV >96 HOURS WITHOUT MCC (MDC 18)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

  • HCC 2 — Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock

Other models: CMS-HCC V22 HCC 2

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for R65.21 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on R65.21 itself; “inherited from” names the category or block whose note applies here.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Code First

Underlying conditions that must be sequenced before this code.

  • underlying infection, such as:
  • infection following a procedure (T81.4-)
  • infections following infusion, transfusion and therapeutic injection (T80.2-)
  • puerperal sepsis (O85)
  • sepsis following complete or unspecified spontaneous abortion (O03.87)
  • sepsis following ectopic and molar pregnancy (O08.82)
  • sepsis following incomplete spontaneous abortion (O03.37)
  • sepsis following (induced) termination of pregnancy (O04.87)
  • sepsis NOS (A41.9)

Source: inherited from R65.2

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code to identify specific acute organ dysfunction, such as:
  • acute kidney failure (N17.-) inherited from R65.2
  • acute respiratory failure (J96.0-) inherited from R65.2
  • critical illness myopathy (G72.81) inherited from R65.2
  • critical illness polyneuropathy (G62.81) inherited from R65.2
  • disseminated intravascular coagulopathy DIC
  • encephalopathy (metabolic) (septic) (G93.41) inherited from R65.2
  • hepatic failure (K72.0-) inherited from R65.2

Coder workflow for R65.21

MedCoder structured workflow — derived from this code’s own official record

Before you code R65.21

  1. Check whether an established diagnosis that explains this sign or symptom is documented. If one is, review whether the documented diagnosis changes the coding pathway: a symptom that is integral to a confirmed diagnosis is not reported separately, while one not routinely associated with it may be. Signs and symptoms are reported when no definitive diagnosis is established (Guidelines I.B.4, I.B.5, I.B.6, I.C.18.b).

    Guide: Symptom code vs confirmed diagnosis →

  2. R65.21’s title joins a condition with an associated condition or complication. Confirm each component is documented. Where the classification presumes the link through the “with” convention, only a provider statement that the conditions are unrelated defeats it. A combination code is assigned only when it fully identifies the documented conditions; a required second code for the stage, type or manifestation is still reported when the notes ask for it (Guidelines I.B.9, I.A.15).

    Guide: Combination codes →

  3. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with R65.21. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Is an established diagnosis that explains this sign or symptom documented?
    Yes → Review whether the documented diagnosis changes the coding pathway: a symptom integral to it is not reported separately.
    No → Continue — the sign or symptom code stands when no definitive diagnosis is established.
  2. Does the documentation support a condition named in R65.21’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewT81.12

  3. Is the underlying (etiologic) condition the Code First note names documented?
    Yes → Sequence the underlying condition first, then R65.21.
    No → Continue; do not add an underlying condition the record does not document.

    ReviewT81.4, T80.2, O85, O03.87, O08.82, O03.37

Consider R65.21. Then work the Use Additional Code note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Severity
Mild, moderate or severe as the provider states it; severity is not inferred from the clinical picture.
The associated condition or complication
Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).
The underlying (etiologic) condition
Named in the Code First note; sequenced before this code when documented (Guidelines I.A.13).
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Official instructions as workflow

  • Excludes1 — check before selecting R65.21(1 note)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with R65.21: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareT81.12

    See the official tabular notes · Guidelines I.A.12.a

  • Code First — sequencing check(9 notes)

    Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before R65.21. Do not add an underlying condition the record does not document.

    ReviewT81.4, T80.2, O85, O03.87, O08.82, O03.37

    See the official tabular notes · Guidelines I.A.13

  • Use Additional Code — after identifying R65.21(8 notes)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with R65.21 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    ReviewN17, J96.0, G72.81, G62.81, G93.41, K72.0

    See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The sign or symptom is documented, and the same record establishes a diagnosis that routinely includes it.

Coding question: Is R65.21 reported in addition to the diagnosis?

Path: Review the documented diagnosis and whether the classification treats this finding as integral to it.

Reason: Signs and symptoms integral to a confirmed diagnosis are not coded separately; those not routinely associated with it may be reported when present (Guidelines I.B.5, I.B.6, I.C.18.b).

Documentation: Both the condition R65.21 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewT81.12

Documentation: Only one of the components this code’s title joins is documented.

Coding question: Is R65.21 supported?

Path: Review the code for the documented component on its own.

Reason: A combination code is assigned only when it fully identifies the documented conditions; otherwise the documented component takes its own code (Guidelines I.B.9).

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Don’t confuse R65.21 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of R65.21 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • T81.12— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of postprocedural septic shock moves the case to T81.12; the two are not reported together unless documented as unrelated.

    Full comparison: R65.21 vs T81.12 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Severe sepsis with septic shock is a billable ICD-10-CM diagnosis code (R65.21).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99), U07.1, U09.9 a. Human Immunodeficiency Virus (HIV) Infections 1) Code only confirmed cases

For cases of septic shock, the code for the systemic infection should be sequenced first, followed by code R65.21, Severe sepsis with septic shock or code T81.12, Postprocedural septic shock. Any additional codes for the other acute organ dysfunctions should also be assigned. As noted in the sequencing instructions in the Tabular List, the code for septic shock cannot be assigned as a principal diagnosis.

Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99), U07.1, U09.9 a. Human Immunodeficiency Virus (HIV) Infections 1) Code only confirmed cases

(c) Postprocedural infection and postprocedural septic shock If a postprocedural infection has resulted in postprocedural septic shock, assign the codes indicated above for sepsis due to a postprocedural infection, followed by code T81.12-, Postprocedural septic shock. Do not assign code R65.21, Severe sepsis with septic shock. Additional code(s) should be assigned for any acute organ dysfunction.

Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99), U07.1, U09.9 a. Human Immunodeficiency Virus (HIV) Infections 1) Code only confirmed cases

A code from subcategory R65.2, Severe sepsis, should not be assigned unless severe sepsis or an associated acute organ dysfunction is documented.

Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99), U07.1, U09.9 a. Human Immunodeficiency Virus (HIV) Infections 1) Code only confirmed cases

If a patient has sepsis and an acute organ dysfunction, but the medical record documentation indicates that the acute organ dysfunction is related to a medical condition other than the sepsis, do not assign a code from subcategory R65.2, Severe sepsis. An acute organ dysfunction must be associated with the sepsis in order to assign the severe sepsis code. If the documentation is not clear as to whether an acute organ dysfunction is related to the sepsis or another medical condition, query the provider.

Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99), U07.1, U09.9 a. Human Immunodeficiency Virus (HIV) Infections 1) Code only confirmed cases

(b) Severe sepsis The coding of severe sepsis requires a minimum of 2 codes: first a code for the underlying systemic infection, followed by a code from subcategory R65.2, Severe sepsis. If the causal organism is not documented, assign code A41.9, Sepsis, unspecified organism, for the infection. Additional code(s) for the associated acute organ dysfunction are also required.

Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99), U07.1, U09.9 a. Human Immunodeficiency Virus (HIV) Infections 1) Code only confirmed cases

3) Sequencing of severe sepsis If severe sepsis is present on admission, and meets the definition of principal diagnosis, the underlying systemic infection should be assigned as principal diagnosis followed by the appropriate code from subcategory R65.2 as required by the sequencing rules in the Tabular List. A code from subcategory R65.2 can never be assigned as a principal diagnosis. When severe sepsis develops during an encounter (it was not present on admission), the underlying systemic infection and the appropriate code from subcategory R65.2 should be assigned as secondary diagnoses.

Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99), U07.1, U09.9 a. Human Immunodeficiency Virus (HIV) Infections 1) Code only confirmed cases

4) Sepsis or severe sepsis with a localized infection If the reason for admission is sepsis or severe sepsis and a localized infection, such as pneumonia or cellulitis, a code(s) for the underlying systemic infection should be assigned first and the code for the localized infection should be assigned as a secondary diagnosis. If the patient has severe sepsis, a code from subcategory R65.2 should also be assigned as a secondary diagnosis. If the patient is admitted with a localized infection, such as pneumonia, and sepsis/severe sepsis doesn’t develop

Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99), U07.1, U09.9 a. Human Immunodeficiency Virus (HIV) Infections 1) Code only confirmed cases

(b) Sepsis due to a postprocedural infection For sepsis following a postprocedural wound (surgical site) infection, a code from T81.41 to T81.43, Infection following a procedure, T81.49, Infection following a procedure, other surgical site, or a code from O86.00 to O86.03, Infection of obstetric surgical wound, or code O86.09, Infection of obstetric surgical wound, other surgical site, that identifies the site of the infection should be sequenced first, if known. Assign an additional code for sepsis following a procedure (T81.44) or sepsis following an obstetrical procedure (O86.04). Use an additional code to identify the infectious agent. If the patient has severe sepsis, the appropriate code from subcategory R65.2 should also be assigned with the additional code(s) for any acute organ dysfunction.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

  1. Sequencing: 9 Code First instructions — the underlying condition is sequenced before this code when present. See the Code First notes
  2. 8 Use Additional Code instructions — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
  3. 1 Excludes1 entry — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

  • Principal-diagnosis restriction. The Medicare Code Editor lists this code as unacceptable as a principal diagnosis: it describes a circumstance influencing health status rather than a current illness or injury being treated. It is valid as a secondary diagnosis.
  • MCC as a secondary diagnosis (FY2027). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder-derived relationships — computed from published CMS and AHRQ datasets

Other codes that name R65.21 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: T79.4 — Traumatic shock.

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 1 Excludes2 note: R57.0 — Cardiogenic shock.

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Referenced by 9 Use Additional Code instructions across 3 chapters: O03.37 — Sepsis following incomplete spontaneous abortion (via R65.2.-), O03.87 — Sepsis following complete or unspecified spontaneous abortion (via R65.2.-), O04.87 — Sepsis following (induced) termination of pregnancy (via R65.2.-), O07.37 — Sepsis following failed attempted termination of pregnancy (via R65.2.-), O08.82 — Sepsis following ectopic and molar pregnancy (via R65.2.-), O85 — Puerperal sepsis (via R65.2.-), P36 — Bacterial sepsis of newborn (via R65.2.-), T80.2 — Infections following infusion, transfusion and therapeutic injection (via R65.2.-), T81.4 — Infection following a procedure (via R65.2.-).

These codes instruct coders to additionally report this code when it applies.

Referenced by 1 Code Also instruction: M35.81 — Multisystem inflammatory syndrome (via R65.2.-).

These codes suggest coding this condition alongside when both are present.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: MCC — Major Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 48 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 3 MS-DRGs: DRG 870 (MDC 18), DRG 871 (MDC 18), DRG 872 (MDC 18).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):INF002 — Septicemia (default); SYM003 — Shock.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as MCC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

R46.3 — Overactivity, R46.4 — Slowness and poor responsiveness, R46.5 — Suspiciousness and marked evasiveness, R46.6 — Undue concern and preoccupation with stressful events, R46.7 — Verbosity and circumstantial detail obscuring reason for contact, R52 — Pain, unspecified, R57.0 — Cardiogenic shock, R57.1 — Hypovolemic shock, R57.8 — Other shock, R57.9 — Shock, unspecified, R68.0 — Hypothermia, not associated with low environmental temperature, R68.11 — Excessive crying of infant (baby), R68.12 — Fussy infant (baby), R68.13 — Apparent life threatening event in infant (ALTE), R68.19 — Other nonspecific symptoms peculiar to infancy, R68.81 — Early satiety, R68.82 — Decreased libido, R68.83 — Chills (without fever), R68.89 — Other general symptoms and signs, R69 — Illness, unspecified, +28 more

Principal diagnosis restriction (Medicare Code Editor)

Not acceptable as a principal diagnosis on an inpatient claim.

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock) for risk-adjusted payment.

B00.7 — Disseminated herpesviral disease, B37.7 — Candidal sepsis, M35.81 — Multisystem inflammatory syndrome, P02.70 — Newborn affected by fetal inflammatory response syndrome, P36.0 — Sepsis of newborn due to streptococcus, group B, P36.10 — Sepsis of newborn due to unspecified streptococci, P36.19 — Sepsis of newborn due to other streptococci, P36.2 — Sepsis of newborn due to Staphylococcus aureus, P36.30 — Sepsis of newborn due to unspecified staphylococci, P36.39 — Sepsis of newborn due to other staphylococci, P36.4 — Sepsis of newborn due to Escherichia coli, P36.5 — Sepsis of newborn due to anaerobes, P36.8 — Other bacterial sepsis of newborn, P36.9 — Bacterial sepsis of newborn, unspecified, R57.1 — Hypovolemic shock, R57.8 — Other shock, R65.10 — Systemic inflammatory response syndrome (SIRS) of non-infectious origin without acute organ dysfunction, R65.11 — Systemic inflammatory response syndrome (SIRS) of non-infectious origin with acute organ dysfunction, R65.20 — Severe sepsis without septic shock, T79.4XXA — Traumatic shock, initial encounter, +31 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Septicemia, Shock).

P36.10 — Sepsis of newborn due to unspecified streptococci, P36.19 — Sepsis of newborn due to other streptococci, P36.2 — Sepsis of newborn due to Staphylococcus aureus, P36.30 — Sepsis of newborn due to unspecified staphylococci, P36.39 — Sepsis of newborn due to other staphylococci, P36.4 — Sepsis of newborn due to Escherichia coli, P36.5 — Sepsis of newborn due to anaerobes, P36.8 — Other bacterial sepsis of newborn, P36.9 — Bacterial sepsis of newborn, unspecified, R57.0 — Cardiogenic shock, R57.1 — Hypovolemic shock, R57.8 — Other shock, R57.9 — Shock, unspecified, R65.20 — Severe sepsis without septic shock, T81.10XA — Postprocedural shock unspecified, initial encounter, T81.11XA — Postprocedural cardiogenic shock, initial encounter, T81.12XA — Postprocedural septic shock, initial encounter, T81.19XA — Other postprocedural shock, initial encounter, T81.44XA — Sepsis following a procedure, initial encounter, T88.2XXA — Shock due to anesthesia, initial encounter, +44 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Shock”, “Sepsis”; these codes share that main term but sit in a different category of the Tabular List.

P36.30 — Sepsis of newborn due to unspecified staphylococci (newborn, due to, Staphylococcus), P36.39 — Sepsis of newborn due to other staphylococci (newborn, due to, Staphylococcus, specified NEC), P36.4 — Sepsis of newborn due to Escherichia coli (newborn, due to, Escherichia coli), P36.5 — Sepsis of newborn due to anaerobes (newborn, due to, anaerobes NEC), P36.8 — Other bacterial sepsis of newborn (newborn, specified NEC), P36.9 — Bacterial sepsis of newborn, unspecified (newborn), R57.0 — Cardiogenic shock (cardiogenic), R57.1 — Hypovolemic shock (hypovolemic), R57.8 — Other shock (hematologic), R57.9 — Shock, unspecified, T75.01 — Shock due to being struck by lightning (lightning), T75.4 — Electrocution (electric), T78.00 — Anaphylactic reaction due to unspecified food (anaphylactic, due to food), T78.01 — Anaphylactic reaction due to peanuts (anaphylactic, due to food, peanuts), T78.02 — Anaphylactic reaction due to shellfish (crustaceans) (anaphylactic, due to food, fish, shellfish), T78.03 — Anaphylactic reaction due to other fish (anaphylactic, due to food, fish), T78.04 — Anaphylactic reaction due to fruits and vegetables (anaphylactic, due to food, fruit), T78.05 — Anaphylactic reaction due to tree nuts and seeds (anaphylactic, due to food, nuts), T78.06 — Anaphylactic reaction due to food additives (anaphylactic, due to food, additives), T78.070 — Anaphylactic reaction due to milk and dairy products with tolerance to baked milk (anaphylactic, due to food, milk, with, tolerance to baked milk), +98 more

Contextual Map

Every relationship of R65.21 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run R65.21 with these 12 related codes in Claim Check

Hierarchy

Excludes1

Referenced by Excludes1 notes

  • T79.4 — Traumatic shock[Excludes1]: “septic shock (R65.21)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2027

Referenced by Excludes2 notes

Referenced by Use Additional Code instructions (9)

Referenced by Code Also instructions

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 2 — Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock [CMS-HCC]— CMS-HCC V28 · 2026

MS-DRG Grouper

MDC crossing

  • MDC 18 — Infectious and Parasitic Diseases, Systemic or Unspecified Sites[MDC crossing]: “Infectious and Parasitic Diseases, Systemic or Unspecified Sites — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 1 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Index entries

  • Infection, infected, infective (opportunistic), with, organ dysfunction (acute), with septic shock[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Sepsis (generalized) (unspecified organism), severe, with septic shock[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Sepsis (generalized) (unspecified organism), with, organ dysfunction (acute) (multiple), with septic shock[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Severe sepsis, with septic shock[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Shock, endotoxic[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Shock, gram-negative[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Shock, septic (due to severe sepsis)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Relevant guides

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

Indexed Clinical Terms (7)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2027), quoted by section Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v44 Release, file and checksum · Publisher’s page
Risk adjustment Official source data
2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder-derived relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder editorial explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 20, 2026 · All releases and sources

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Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "R65.21 — Severe sepsis with septic shock." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/r65.21-severe-sepsis-with-septic-shock

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Severe sepsis with septic shock

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to R65.21 in its code family, with their registry titles.

View all codes in the R65 family