ICD-10 J18.9
Billable / Specific MCCPneumonia, unspecified organism
About ICD-10-CM J18.9
ICD-10-CM code J18.9 represents Pneumonia, unspecified organism. This is a billable/specific code in the Respiratory System chapter (block J18). The 2026 edition of ICD-10-CM J18.9 became effective on October 1, 2025.
Coding Tips for J18.9
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
J18.9 is designated MCC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-MCC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag MCC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Inpatient DRG Impact, MCC
codes Pneumonia, unspecified organism. As a Major Complication/Comorbidity (MCC), this can shift the DRG assignment to a higher-weighted category, substantial reimbursement impact.
Medicare LCD Coverage for J18.9
Local Coverage Determinations (LCDs) from CMS MACs that list J18.9 as a covered diagnosis.
Showing top 10 of 671 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing J18.9.
3 Aetna
1 Cigna
5 Medicare
CPT Codes Commonly Billed with J18.9
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 71046 Chest X-ray 2 views — cough, dyspnea, wheezing, chest pain, pneumonia, COPD exacerbation, asthma exacerbation, respiratory failure, lung nodule, pneumothorax, heart failure, hx pneumonia, TB, hypoxemia Radiology
- 31622 Diagnostic bronchoscopy — pulmonary nodule, lung cancer, hemoptysis, lung disease, chronic cough, pneumonia, lung mets, abnormal sputum cytology Pulmonology
- 99283 ED visit level 3 — chest pain, dyspnea, pneumonia, UTI, forearm fracture, tibia fracture, syncope, GI bleed Emergency Medicine
Convert J18.9 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| J18.9 | 486 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To J18.9
Other codes in section J09-J18 (Influenza and pneumonia).
ICD-10 J18.9, Billing FAQ
Is ICD-10 code J18.9 billable? +
Yes, J18.9 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
Is J18.9 a CC or MCC for inpatient DRG? +
Yes, this code is designated as MCC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What CPT codes are commonly billed with J18.9? +
Procedures frequently paired with J18.9 include: 71046, 31622, 99283.
What ICD-9 codes does J18.9 map to? +
Per CMS GEMs, J18.9 maps to ICD-9 codes: 486. Useful for legacy data review and historical claim analysis.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on June 1, 2026.
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