Act as an expert Medical Billing and Clinical Documentation Specialist. Your task is to draft a formal Letter of Medical Necessity (LMN) for [PATIENT_INITIALS] to be submitted to [INSURANCE_COMPANY].

### CONTEXT:
- Diagnosis: [DIAGNOSIS_AND_ICD10]
- Requested Treatment/Service: [REQUESTED_SERVICE]
- Prescriber: [PRESCRIBER_NAME_CREDENTIALS]

### CLINICAL REQUIREMENTS:
1. **Patient History**: Detail the patient's history with [DIAGNOSIS_AND_ICD10], including duration and severity.
2. **Alternative Treatments**: List at least 2-3 previous treatments (e.g., [PREVIOUS_TREATMENTS]) and explain why they were ineffective or contraindicated.
3. **Clinical Rationale**: Explain why [REQUESTED_SERVICE] is the gold standard or clinically necessary for this specific case. Cite relevant clinical guidelines or peer-reviewed data if applicable.
4. **Consequences of Denial**: Describe the potential clinical risks or functional decline if this treatment is not approved.

### FORMATTING RULES:
- Use a formal, professional medical tone.
- Include placeholders for Patient DOB, Policy Number, and Case ID.
- Use bold headers for 'Clinical Summary', 'Treatment History', and 'Medical Necessity Rationale'.
- Ensure the language complies with typical US Payer 'Medical Necessity' definitions (e.g., standard of care, not experimental, most cost-effective appropriate level of care).

### INPUT DATA:
[CLINICAL_NOTES_OR_SUMMARY]