Draft prior auth letters and LMNs
Paste clinical notes and request details — River generates a complete letter of medical necessity or prior auth narrative ready to submit.
No credit card required • Your notes stay private
River's Prior Auth & LMN Generator drafts complete letters of medical necessity, prior authorization clinical narratives, payer portal answers, documentation checklists, and PA appeal letters. Paste the clinical notes and request details, select the request type and output you need, and the AI generates documentation tailored to the payer's criteria — covering clinical background, medical necessity rationale, failed alternative documentation, and the specific request.
Prior authorization has become one of the most time-consuming administrative burdens in medicine. Physicians spend an average of 14+ hours per week on prior auth tasks. Poorly written LMNs that fail to address the payer's criteria are denied at high rates, requiring additional physician time for appeals. This tool helps you write documentation that directly addresses what payers want to see.
Use this for medication prior auths, imaging requests, DME authorizations, surgical procedures, therapy continuations, or any service requiring a letter of medical necessity or clinical narrative.
Writing Prior Auth Documentation That Gets Approved
Payers review prior authorization requests against their coverage criteria — often a clinical policy guideline or LCD/NCD. The most effective requests address those criteria explicitly, in the payer's own language. If the payer requires 'two prior failures of formulary alternatives,' document exactly which drugs were tried, at what doses, for how long, and why they were discontinued. Generic requests that do not address the criteria rarely succeed.
For medications, step therapy documentation is critical. List each step-therapy drug: name, dose, duration of treatment, outcome, and reason for discontinuation (inadequate response, adverse effect, contraindication). If the patient was on a drug before coverage began, document that with as much specificity as possible. For specialty medications (biologics, specialty injectables), also address the clinical criteria (diagnosis confirmation, severity metrics, lab values) specified in the payer's criteria.
Urgency matters. If the patient needs expedited review, document the specific clinical reason delay is harmful: 'Delay of this [treatment] would result in [specific consequence].' For cancer treatment, transplant preparation, acute decompensation, or pending inpatient discharge, expedited review requests are appropriate and should include the treating physician's direct contact information.
What You Get
Complete letter of medical necessity in formal business letter format
Prior auth clinical narrative for payer portal submission
Payer portal Q&A answers
Documentation checklist for complete PA submission
Step therapy and failed alternatives documentation
Expedited review documentation when time-sensitive
How It Works
- 1Paste clinical notes and request detailsInclude diagnosis, requested service, relevant clinical findings, and prior treatments
- 2Select output type and request typeChoose LMN, portal answers, checklist, or appeal, and the type of service
- 3AI drafts the documentationRiver generates complete prior auth documentation addressing payer criteria
- 4Review, sign, and submitReview, add physician signature information, and submit to the payer
Frequently Asked Questions
Can I paste the payer's coverage criteria to improve the output?
Yes — this is one of the most effective things you can do. If you have the payer's clinical policy or coverage criteria, paste it along with the clinical notes. The AI will use the criteria as a framework and explicitly address each criterion in the output, significantly improving the documentation.
Does this work for Medicare LCDs and NCDs?
Yes. For Medicare LCD (Local Coverage Determination) and NCD (National Coverage Determination) requests, include the LCD/NCD name or number in your notes if available. The AI will structure the documentation to address the covered indications and medical necessity criteria specified in those policies.
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