J10.1: Influenza due to other identified influenza virus with other respiratory manifestations

The ICD-10-CM code for influenza A when the provider names the virus in the record and the note documents respiratory manifestations short of pneumonia.

Billable

FY2027

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At a glance

Code Family

J10: Influenza due to other identified influenza virus.

DRG Grouping

MS-DRG 193, 194 or 195 in MDC 04 under the FY2027 MS-DRG v44 grouper, depending on whether a secondary CC or MCC is reported.

HCC Mapping (v28)

None. Code J10.1 maps to no HCC in the CMS-HCC v28 mapping.

Condition

Influenza A

Family Specificity

Four subcategories split on the manifestation the note documents, with J10.1 carrying the inclusion term Influenza due to other identified influenza virus NOS.

Billable

Yes, a valid four character code. Its parent J10 is a category header and cannot be reported.

Which J10 code do I assign?

The code turns first on whether the record identifies the virus: an identified novel influenza A virus goes to J09.X-, an identified non-novel virus to J10.-, and an unidentified virus to the J11 codes. Within category J10 the split is by manifestation, with J10.1 carrying influenza that has respiratory manifestations short of pneumonia.

When documentation says…

Code

Rapid influenza A antigen positive, provider documents influenza A with cough and sore throat

J10.1

Influenza due to other identified influenza virus with other respiratory manifestations. Category J10 carries an Includes note listing influenza A non-novel, influenza B and influenza C. Code J10.1 carries the inclusion term Influenza due to other identified influenza virus NOS. That makes it the J10 entry for influenza A where the note records no manifestation beyond the respiratory tract. Influenza A/H1N1 and influenza A/H3N2 both land here.

Flu diagnosed clinically, note names no virus type

J11.1

Influenza due to unidentified influenza virus with other respiratory manifestations. Code J11.1 carries the inclusion term Influenza NOS. The FY2027 Alphabetic Index main term Influenza, qualified in parentheses as unidentified influenza virus, defaults to J11.1. Category J10 requires the record to identify the virus. Where the note says only flu or influenza, J11.1 is the code.

Provider documents probable influenza A, PCR pending

J11.1

Influenza due to unidentified influenza virus with other respiratory manifestations. Guideline I.C.10.c of the FY2027 ICD-10-CM Official Guidelines directs a code from category J11 where the provider records influenza as suspected, possible or probable. It states that neither a J09 code nor a J10 code is assigned in that case. This is an explicit exception to Section II.H, the hospital inpatient uncertain diagnosis rule.

Influenza A confirmed, chest imaging shows pneumonia, no organism named for the pneumonia

J10.00

Influenza due to other identified influenza virus with unspecified type of pneumonia. Subcategory J10.0 covers influenza with pneumonia and carries a Code also instruction for an associated lung abscess (J85.1). Code J10.01 applies where the pneumonia is attributed to the same identified influenza virus. Code J10.08 applies where another type of pneumonia is named. Code J10.08 carries its own Code also instruction for that pneumonia.

Influenza A with nausea, vomiting and diarrhea

J10.2

Influenza due to other identified influenza virus with gastrointestinal manifestations. The FY2027 tabular lists Influenza due to other identified influenza virus gastroenteritis as an inclusion term. Code J10.2 carries an Excludes1 note for intestinal flu, viral gastroenteritis (the A08 codes). Category A08 carries the reciprocal Excludes1 note. The two are not reported together for the same condition.

Influenza A with documented encephalopathy

J10.81

Influenza due to other identified influenza virus with encephalopathy. Subcategory J10.8 covers manifestations outside the respiratory and gastrointestinal tracts. Code J10.82 covers myocarditis and code J10.83 covers otitis media. Code G94 carries an Excludes1 note for encephalopathy in influenza (J09.X9, J10.81, J11.81). Code I41 carries the matching Excludes1 note for influenzal myocarditis. Code H67 carries it for otitis media in influenza.

Public health laboratory confirms avian influenza A/H5N1 or a swine origin variant virus

J09.X2

Influenza due to identified novel influenza A virus with other respiratory manifestations. Subcategory J09.X carries the inclusion terms Avian influenza, Bird influenza, Influenza A/H5N1, Influenza of other animal origin not bird or swine, and Swine influenza virus. Category J09 carries an Excludes1 note for influenza A/H1N1 (the J10 codes). It carries further Excludes1 notes directing seasonal influenza due to other identified influenza virus to the J10 codes and seasonal influenza due to unidentified influenza virus to the J11 codes.

Tabular notes

EXCLUDES1

Category J10 carries three Excludes1 entries: influenza due to avian influenza virus (J09.X-), influenza due to swine flu (J09.X-) and influenza due to unidentified influenza virus (the J11 codes). An Excludes1 note means the two codes are not reported together for the same condition. A single episode cannot carry both J10.1 and J11.1. Category J10 also carries an Includes note listing influenza A non-novel, influenza B and influenza C. Category J09 carries the reciprocal set of five Excludes1 entries: influenza A/H1N1 (J10.-), influenza due to other identified influenza virus (J10.-), influenza due to unidentified influenza virus (J11.-), seasonal influenza due to other identified influenza virus (J10.-) and seasonal influenza due to unidentified influenza virus (the J11 codes). Four further Excludes1 notes sit outside category J10 and name J10.1 directly. They sit at code J00, acute nasopharyngitis and the common cold; code J02.9, acute pharyngitis unspecified; subcategory J03.9, acute tonsillitis unspecified; and category J06, acute upper respiratory infections of multiple and unspecified sites. Each excludes influenza virus with other respiratory manifestations (J09.X2, J10.1, J11.1). Where influenza A is the documented diagnosis, J10.1 replaces the upper respiratory infection code rather than sitting beside it. Code J10.1 itself carries no Excludes note. Category J11 carries no Excludes note of its own in the FY2027 tabular. The Excludes1 notes at category J09 and at category J10 are what separate the three categories.

EXCLUDES2

Block J09–J18, influenza and pneumonia, carries nine Excludes2 entries: allergic or eosinophilic pneumonia (J82), aspiration pneumonia NOS (J69.0), congenital pneumonia (P23.9), lipid pneumonia (J69.1), meconium pneumonia (P24.01), neonatal aspiration pneumonia (P24.-), pneumonia due to solids and liquids (J69.-), rheumatic pneumonia (I00) and ventilator associated pneumonia (J95.851). An Excludes2 note means the excluded condition is not part of the block. The patient may carry both conditions. Both codes may be reported where both are documented. Chapter 10 carries an Excludes2 entry for certain infectious and parasitic diseases (A00–B99). Chapter 1 carries the reciprocal Excludes2 entry for influenza and other acute respiratory infections (J00–J22).

USE ADDITIONAL

Code J10.1 carries two Use additional instructions. The first is a code for associated pleural effusion, if applicable (J91.8). The second is a code for associated sinusitis, if applicable (the J01 codes). Block J09–J18 carries a Use additional instruction to identify resistance to antimicrobial drugs (the Z16 codes). Chapter 10 carries a Use additional instruction covering tobacco exposure and use: exposure to environmental tobacco smoke (Z77.22), exposure to tobacco smoke in the perinatal period (P96.81), history of tobacco dependence (Z87.891), occupational exposure to environmental tobacco smoke (Z57.31), tobacco dependence (F17.-) and tobacco use (Z72.0).

CODE ALSO

Two categories outside J10 carry a Code also instruction that names J10.1. Category J04, acute laryngitis and tracheitis, instructs the coder to code also influenza if present, listing J09.X2, J10.1 and J11.1. Category J05, acute obstructive laryngitis croup and epiglottitis, carries the same instruction. The instruction sits at J04 and J05 rather than at J10.1. A J04 or J05 code is reported alongside the influenza code under that instruction. Influenza with pharyngitis is not reported alongside J02.9 for the same condition, because J02.9 carries an Excludes1 entry for J10.1. Subcategory J10.0 carries its own Code also instruction for an associated lung abscess (J85.1).

CODE FIRST

Code J91.8, pleural effusion in other conditions classified elsewhere, carries a Code first instruction for the underlying disease, listing influenza (J09.X2, J10.1, J11.1). That instruction is the reciprocal of the Use additional note at J10.1. Where an influenzal pleural effusion is documented, J10.1 sequences first and J91.8 follows.

FY2027: EFFECTIVE 1 OCTOBER 2026

Code J10.1 is valid in the FY2026 code set and unchanged in the FY2027 update. Its descriptor, its four inclusion terms and its two Use additional instructions are unchanged. Category J10 still holds four subcategories: J10.0, J10.1, J10.2 and J10.8. No code was added to or deleted from category J09, J10 or J11 for FY2026. The FY2027 codes and tabular addenda make no addition, deletion or revision in category J09, J10 or J11. The FY2027 MS-DRG grouper is Version 44.0, for discharges on or after 1 October 2026.

Operational & financial impact

Why specificity matters beyond the chart: risk adjustment, DRG assignment and denial exposure all follow from which code is selected.

CMS-HCC v28 (PY2024+)

None. Code J10.1 maps to no HCC in the CMS-HCC v28 mapping.

The v28 model carries one pneumonia category, HCC 282, Aspiration and Specified Bacterial Pneumonias. Its code list holds A48.1, a set of J15 bacterial pneumonia codes and the J69 pneumonitis codes. No J09, J10 or J11 code appears in it.

No other v28 respiratory category covers influenza. The respiratory and lung infection categories in v28 are HCC 211, HCC 212, HCC 213, HCC 276, HCC 277, HCC 278, HCC 279, HCC 280, HCC 282 and HCC 283.

Codes J11.1 and J09.X2 map to no HCC either. Moving between the three influenza categories changes no risk adjustment weight.

Influenza is an acute self limited infection. The CMS-HCC model carries chronic and high cost conditions.

CMS-HCC v28 is fully phased in at 100 percent for payment year 2026.

MS-DRG v44 (FY2027)

MS-DRG 193: Simple pneumonia and pleurisy with MCC.

MS-DRG 194: Simple pneumonia and pleurisy with CC.

MS-DRG 195: Simple pneumonia and pleurisy without CC/MCC.

All three sit in MDC 04, Diseases and Disorders of the Respiratory System. All three are medical MS-DRGs.

With J10.1 as the principal diagnosis, the case groups to MS-DRG 195 unless a secondary diagnosis on the CC or MCC list is also reported. A reported secondary CC moves the case to MS-DRG 194. A reported secondary MCC moves it to MS-DRG 193.

Codes J09.X1 and J09.X2 group to the same MS-DRG 193, 194 and 195 set. Appendix B lists J10.00, J10.01, J10.08, J11.00 and J11.08 under that set and also under MS-DRG 177, 178 and 179, Respiratory Infections and Inflammations.

Version 44.0 of the grouper applies to discharges on or after 1 October 2026.

Medicare and commercial payers

These MS-DRG rules apply to Medicare Fee for Service inpatient claims. The CMS-HCC v28 rules apply to Medicare Advantage plans for payment year 2026.

Code J10.1 is complete at four characters and needs no further characters.

An influenza encounter billed on a professional claim carries no DRG at all. There the diagnosis code supports medical necessity for the rapid influenza antigen test, for influenza PCR and for an antiviral prescription.

WHERE SPECIFICITY IS LOST

Where the provider named influenza A and J11.1 was assigned, the claim reports an unidentified virus. Under the FY2027 MS-DRG v44 grouper J11.1 groups to MS-DRG 152 and MS-DRG 153, otitis media and upper respiratory infection, in MDC 03. Code J10.1 groups to MS-DRG 193, 194 and 195 in MDC 04. The J10 to J11 choice moves the case across major diagnostic categories.

Where the note named no virus type and J10.1 was assigned, the code asserts an identification the record does not carry. Guideline I.C.10.c requires a provider diagnostic statement naming the virus.

Where pneumonia was documented and J10.1 was assigned, the record misses subcategory J10.0. Appendix B lists J10.00, J10.01 and J10.08 under the same MS-DRG 193, 194 and 195 set as J10.1, and also under MS-DRG 177, 178 and 179. The miss can therefore change the base DRG as well as the clinical record.

Where gastrointestinal manifestations were documented and J10.1 was assigned, the record misses J10.2. Code J10.2 groups to MS-DRG 865 and MS-DRG 866, viral illness, rather than to the simple pneumonia and pleurisy pair.

Where a novel influenza A virus was identified and J10.1 was assigned, category J09 is missed. Category J09 carries an Excludes1 note for influenza A/H1N1 (the J10 codes). A seasonal H1N1 case does not belong in J09 either.

None of these choices changes the HCC. Code J10.1 carries no v28 HCC.

SEVERITY DESIGNATION (MS-DRG V44.0)

J10.1 carries no severity designation. It appears in neither Appendix G, the CC list, nor Appendix H, the MCC list, of the ICD-10 MS-DRG Definitions Manual Version 44.0. A case reaches the higher tier of its DRG pair on a designation carried by another diagnosis.

Documentation checklist to support J10.1

Chart elements that support code selection and reduce specificity-driven denials.

A provider diagnostic statement naming the influenza virus, such as influenza A, influenza B or influenza A/H1N1.

The result of the rapid influenza antigen test or the influenza PCR, where testing was performed.

The link between that result and the diagnosis. A positive result sitting in the lab section alone does not carry the diagnosis.

Whether the provider stated the diagnosis outright or hedged it. Suspected, possible or probable influenza directs the encounter to J11.1 under guideline I.C.10.c.

The manifestation documented. Pneumonia moves the encounter to subcategory J10.0. Gastrointestinal manifestations move it to J10.2. Encephalopathy, myocarditis and otitis media move it to subcategory J10.8.

Whether the virus is a novel influenza A virus. Avian influenza, influenza A/H5N1 and a swine origin variant virus belong to the J09.X codes rather than to J10.1.

Any associated pleural effusion or sinusitis, to support the Use additional codes at J10.1 for J91.8 and for the J01 sinusitis codes.

Tobacco exposure or use status, to support the chapter 10 Use additional codes.

For outpatient encounters, a confirmed diagnosis. A probable influenza is not coded as confirmed in the outpatient setting.

FAQ

What is the ICD-10 code for influenza A?

The code is J10.1, influenza due to other identified influenza virus with other respiratory manifestations, where the provider names influenza A and the note records respiratory symptoms without pneumonia. Category J10 carries an Includes note for influenza A non-novel. Code J10.1 carries the inclusion term Influenza due to other identified influenza virus NOS. That inclusion term makes J10.1 the default J10 code where no other manifestation is documented. Influenza A with pneumonia belongs to subcategory J10.0. Influenza with no virus type named belongs to J11.1.

Is J10.1 a billable code?

Yes. Code J10.1 is a valid four character billable code. Its parent J10, influenza due to other identified influenza virus, is a category header and cannot be reported on a claim. Category J10 holds nine billable codes: J10.00, J10.01, J10.08, J10.1, J10.2, J10.81, J10.82, J10.83 and J10.89. The subcategory headers J10.0 and J10.8 are not reportable.

What is the difference between J10.1 and J11.1?

The difference is whether the record identifies the virus. Code J10.1 requires the provider to name the virus, such as influenza A, influenza B or influenza C. Code J11.1 applies where no virus is named. The FY2027 Alphabetic Index main term Influenza, qualified in parentheses as unidentified influenza virus, defaults to J11.1. Category J10 carries an Excludes1 note for influenza due to unidentified influenza virus (the J11 codes). An Excludes1 note means the two are not reported together for the same condition. Code J11.1 carries the inclusion terms Influenza NOS, Influenzal laryngitis NOS, Influenzal pharyngitis NOS and Influenza with upper respiratory symptoms NOS.

Does a negative rapid flu test rule out J10.1?

No. Guideline I.C.10.c of the FY2027 ICD-10-CM Official Guidelines states that confirmation does not require documentation of positive laboratory testing. Coding rests on the provider's diagnostic statement. Where the rapid antigen is negative and the provider still documents influenza A as the diagnosis, J10.1 applies. Where the provider instead documents possible or probable influenza, J11.1 applies. A positive result recorded in the lab section without a provider diagnostic statement does not support J10.1 either.

Where does H1N1 belong, J09 or J10?

H1N1 influenza belongs in category J10. Category J09 carries an Excludes1 note for influenza A/H1N1 (the J10 codes). The FY2027 Alphabetic Index carries two entries that settle it. Under the main term Influenza, the subterm novel (2009) H1N1 influenza directs to J10.1. The subterm novel influenza A/H1N1 directs to J10.1. The 2009 pandemic H1N1 virus now circulates as a seasonal strain. Category J09 is reserved for a novel influenza A virus. Subcategory J09.X lists avian influenza, bird influenza, influenza A/H5N1, influenza of other animal origin not bird or swine, and swine influenza virus as its inclusion terms.

Does J10.1 map to an HCC under CMS-HCC v28?

No. Code J10.1 maps to no HCC in the CMS-HCC v28 mapping. The model's one pneumonia category, HCC 282, Aspiration and Specified Bacterial Pneumonias, holds no J09, J10 or J11 code. Codes J11.1 and J09.X2 map to no HCC either. Moving between them changes no risk adjustment weight. HCC mapping and severity designation are separate questions and must be checked separately.

How is J10.1 sequenced, and does the setting change it?

Under Section II of the FY2027 ICD-10-CM Official Guidelines, the principal diagnosis is the condition established after study to be chiefly responsible for the admission. Where J10.1 is the reason for the admission it sequences first. The case then groups to MS-DRG 193, 194 or 195. Where an influenzal pleural effusion is documented, code J91.8 carries a Code first instruction for influenza. Code J10.1 precedes J91.8 in that pairing. On the setting question, guideline I.C.10.c is an explicit exception to Section II.H, the inpatient uncertain diagnosis rule. A probable influenza A documented at discharge on an inpatient record is coded J11.1 rather than J10.1. In the outpatient setting Section IV already bars coding a probable diagnosis as confirmed.

What changed for J10.1 in FY2027?

J10.1 is unchanged in the FY2027 update. Its descriptor, its four inclusion terms and its two Use additional instructions are unchanged. Category J10 still holds four subcategories and nine billable codes. No code was added to or deleted from category J09, J10 or J11 for FY2026. The FY2027 codes and tabular addenda, effective 1 October 2026, make no addition, deletion or revision in those three categories either.

Related codes

Codes in the same family as J10.1. Only codes with a published page render as links.

Sibling codes in the J10 family

J10.00: Influenza due to other identified influenza virus with unspecified type of pneumonia.
J10.01: Influenza due to other identified influenza virus with the same other identified influenza virus pneumonia.
J10.08: Influenza due to other identified influenza virus with other specified pneumonia.
J10.2: Influenza due to other identified influenza virus with gastrointestinal manifestations.
J10.81: Influenza due to other identified influenza virus with encephalopathy.
J10.82: Influenza due to other identified influenza virus with myocarditis.
J10.83: Influenza due to other identified influenza virus with otitis media.
J10.89: Influenza due to other identified influenza virus with other manifestations.

Additional codes to consider

Codes outside the J10 family considered alongside J10.1.

Companion: code alongside when documented

J91.8: Pleural effusion in other conditions classified elsewhere, instructed as a Use additional code at J10.1.
J01-: Acute sinusitis, instructed as a Use additional code at J10.1.
J04.0: Acute laryngitis, whose category carries a Code also instruction for influenza.
J05.0: Acute obstructive laryngitis [croup], whose category carries a Code also instruction for influenza.
Z16-: Resistance to antimicrobial drugs, instructed at block J09–J18.
F17-: Nicotine dependence, instructed at chapter 10.
Z72.0: Tobacco use, instructed at chapter 10.
Z77.22: Contact with and (suspected) exposure to environmental tobacco smoke (acute) (chronic).
Z87.891: Personal history of nicotine dependence.

Consider instead

J11.1: Influenza due to unidentified influenza virus with other respiratory manifestations, where the note names no virus type.
J11.00: Influenza due to unidentified influenza virus with unspecified type of pneumonia, carrying the inclusion term Influenza with pneumonia NOS.
J09.X2: Influenza due to identified novel influenza A virus with other respiratory manifestations, where a novel influenza A virus is identified.
J09.X1: Influenza due to identified novel influenza A virus with pneumonia.
J10.00: Influenza due to other identified influenza virus with unspecified type of pneumonia, where pneumonia is documented.
J10.2: Influenza due to other identified influenza virus with gastrointestinal manifestations, where the note documents influenzal gastroenteritis.
J00: Acute nasopharyngitis [common cold], which carries an Excludes1 entry for J10.1.
J02.9: Acute pharyngitis, unspecified, which carries an Excludes1 entry for J10.1.
J03.90: Acute tonsillitis, unspecified, which sits under an Excludes1 entry for J10.1.
J06.9: Acute upper respiratory infection, unspecified, whose category carries an Excludes1 entry for J10.1.
U07.1: COVID-19, where SARS-CoV-2 rather than influenza is the identified virus.
J12.89: Other viral pneumonia, where a virus other than influenza causes the pneumonia.
A08.4: Viral intestinal infection, unspecified, which code J10.2 carries as an Excludes1 entry.
J20.9: Acute bronchitis, unspecified, where acute bronchitis is documented without influenza.

Sources

All claims on this page derive from government and professional-standards sources.

National Center for Health Statistics. (2026). International classification of diseases, tenth revision, clinical modification (ICD-10-CM) FY2027 files. https://www.cdc.gov/nchs/icd/icd-10-cm/files.html
Centers for Medicare & Medicaid Services and National Center for Health Statistics. (2026). ICD-10-CM official guidelines for coding and reporting FY2027. https://ftp.cdc.gov/pub/Health_Statistics/NCHS/Publications/ICD10CM/2027/ICD-10-CM-October-1-2026-FY27-Guidelines.pdf
Centers for Medicare & Medicaid Services. (2025). 2026 model software/ICD-10 mappings. https://www.cms.gov/medicare/payment/medicare-advantage-rates-statistics/risk-adjustment/2026-model-software-icd-10-mappings
Centers for Medicare & Medicaid Services. (2026). MS-DRG classifications and software, version 44. https://www.cms.gov/medicare/payment/prospective-payment-systems/acute-inpatient-pps/ms-drg-classifications-and-software