Diagnosis & Service Search
Coder safety: This tool assists with code lookup and workflow. It does not replace provider documentation, the official ICD-10-CM guidelines, CPT/HCPCS code books, NCCI edits, payer policy, medical-necessity rules, or professional coding review.
ICD-10-CM results
0Service references
0Modifier guidance
0Code set
FY2027Infectious Disease Quick Reference
Use the diagnosis name as a starting point. The exact ICD-10-CM selection depends on the documented condition, acuity, site, organism, laterality, complications, encounter circumstances, and applicable guidelines.
| Condition / search terms | Common coding considerations | Documentation to look for |
|---|---|---|
| UTI / cystitis / pyelonephritis | Differentiate site and acuity; hematuria may change code selection. | Site, acuity, symptoms, hematuria, culture results, organism when documented. |
| Pneumonia | Identify organism and type when supported; avoid coding an organism solely from suspicion. | Organism, aspiration status, lobar/interstitial/other documented type, severity. |
| Sepsis / severe sepsis / septic shock | Requires careful application of official sepsis guidelines and documented clinical condition. | Sepsis type, source/infection, organ dysfunction, shock, causal relationship. |
| Cellulitis / abscess | Site and laterality can matter; distinguish cellulitis from abscess when documented. | Anatomic site, laterality, organism if known, drainage/procedure details. |
| MRSA / resistant organisms | Organism/resistance coding may be additional to the infection code depending on documentation and guidelines. | Culture, organism, resistance, infection site, colonization vs infection. |
| HIV | Use the current HIV-related guideline framework and documented status/condition. | HIV status, active related condition, treatment/encounter purpose. |
| Tuberculosis | Site, confirmed status, and disease manifestation are important. | Confirmed disease, site, microbiology, treatment status, manifestations. |
| Osteomyelitis | Acute/chronic, site, laterality and other documented specificity may affect code. | Bone/site, laterality, acute/chronic, contiguous/hematogenous if documented. |
| C. difficile infection | Distinguish active infection from history/carrier/colonization documentation. | Confirmed CDI, recurrence when documented, treatment and symptoms. |
| Endocarditis | Type and organism can drive specificity. | Valve/site, acute/subacute/other type, organism, prosthetic status. |
| COVID-19 / influenza / viral infections | Use current-year code set and applicable respiratory/infectious-disease guidance. | Confirmed diagnosis, organism/test status where relevant, manifestations. |
| Hepatitis | Type and acuity are key; distinguish active disease from history/status. | Virus/type, acute/chronic, complications and documented manifestations. |
E/M & Common ID Services Reference
Important: CPT is copyrighted by the American Medical Association. A production system must use properly licensed/current CPT data. The table below is workflow guidance, not a substitute for the official CPT code set.
Office / Outpatient E/M
| Code family | Use | Key point |
|---|---|---|
| 99202–99205 | New patient office/outpatient E/M | Choose the specific level using the current CPT rules and documentation. |
| 99211–99215 | Established patient office/outpatient E/M | Choose the specific level using the current CPT rules and documentation. |
Common laboratory / microbiology services
| Code | Service | Typical ID workflow relevance |
|---|---|---|
| 81001 | Urinalysis, automated, with microscopy | UTI workup when performed and documented. |
| 81002 | Urinalysis, nonautomated, without microscopy | Point-of-care urinalysis workflows. |
| 81003 | Urinalysis, automated, without microscopy | Point-of-care/office laboratory workflows. |
| 87086 | Urine culture, quantitative colony count | Culture workup when performed and reportable. |
| 87088 | Culture, additional identification | Use only when the actual service and current CPT rules support it. |
| 87186 | Susceptibility testing | Antimicrobial susceptibility workflow when performed. |
Do not automatically pair a diagnosis with a CPT service. The service must actually be performed, documented, billable for the setting/provider, and supported by payer rules.
Modifier Decision Guide
| Modifier | Use only when supported | Quick check |
|---|---|---|
| 25 | Significant, separately identifiable E/M service on the same day as another procedure/service. | Was a separately identifiable E/M service performed and documented beyond the usual work of the procedure? |
| 59 | Distinct procedural service when the applicable criteria are met. | Different encounter, site, organ/system, lesion, or other qualifying circumstance per current rules? |
| 91 | Repeat clinical diagnostic laboratory test for a medically necessary reason. | Was the same lab test repeated for clinical reasons, not error, quality control, or confirmation of the original result? |
| 95 | Telemedicine services when required by the applicable payer/current CPT guidance. | Confirm payer and current-year telehealth rules; modifier requirements vary. |
Never add a modifier simply because a claim denied. Modifier use must describe the actual service and circumstances.
Documentation Checklist
Core Coding Rules & Workflow
- Identify the encounter purpose and read the provider documentation completely.
- Find the diagnosis in the current ICD-10-CM Alphabetic Index, then verify it in the Tabular List.
- Follow inclusion, exclusion, “code also,” “use additional code,” laterality, 7th-character, and other Tabular instructions.
- Use the highest level of specificity supported by documentation; do not invent specificity.
- Use signs/symptoms when a definitive diagnosis is not established and the guidelines permit symptom coding.
- For E/M, apply the current CPT E/M rules and document the elements required for the selected level.
- For labs/procedures, bill only services actually performed and supported by documentation.
- Check NCCI edits, bundling, modifier rules, medical necessity, frequency limits and payer policy.
- Verify that every code is valid for the date of service.
- Perform a final documentation-to-code reconciliation before claim submission.
FY2027: CMS states that FY2027 ICD-10-CM files apply to patient encounters from October 1, 2026 through September 30, 2027. The application is labeled FY2027 because that is the next effective code-set period beginning October 1, 2026.
Official Resources
- CMS ICD-10 code files & updates
- FY2027 ICD-10-CM Official Guidelines (CMS PDF)
- CMS valid/excluded ICD code lists
- CMS NCCI information
- AMA CPT resources
Production-data note: ICD-10-CM can be sourced from official government files. CPT/HCPCS content and payer edits require appropriate licensing/current source agreements. Do not treat this static reference page as a complete licensed coding database.