Signal CGM powered by STTIL Solutions

B2B CGM coverage worklist tool for DMEPOS suppliers. Ingests CSV shipment data (Brightree/WellSky exports), calculates coverage expiration per patient using device wear-day rules, and produces a prioritized worklist for proactive outreach — so small DME teams act before claims deny, not after.

Self-hosted. Data never leaves the supplier network.

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What It Does

Most DMEPOS suppliers manage CGM coverage reactively: a claim denies, then staff scramble to appeal. Signal CGM flips that. The system watches coverage windows continuously and surfaces patients approaching expiration before the denial condition exists.

• Ingests shipment CSV from Brightree or WellSky
• Calculates coverage expiration per patient per device using payer-specific wear-day rules
• Flags each patient: REFILL_WINDOW, VISIT_DUE, OUT_OF_COVERAGE, or OK
• Delivers a prioritized worklist to DME staff via encrypted email
• Staff handle outreach locally — Signal CGM never contacts patients directly

Stack

Layer	Technology
Backend	Python / FastAPI
Database	PostgreSQL (encrypted at rest)
Orchestration	n8n (self-hosted, 24-hour batch trigger)
Notifications	Mailcow (self-hosted SMTP — staff email only)
Hosting	Hostinger VPS — data stays on-prem

PHI Architecture

Signal CGM is designed to minimize PHI surface area:

• Sole crosswalk key: patient_id (the supplier's internal MRN or account number). No names, SSNs, DOBs, or contact information enter the system.
• DME staff maintain the patient_id ↔ real identity mapping in their own systems (Brightree, EHR, etc.).
• The calculation layer sees: patient_id, device_type, shipment_date, quantity, payer — nothing else.
• All audit logs hash patient_id before storage. Raw identifiers never appear in logs.

Coverage Flag Logic

Flag	Meaning
REFILL_WINDOW	Patient is within the refillable window — safe to ship
VISIT_DUE	Physician visit renewal is approaching (Medicare: 180 days)
OUT_OF_COVERAGE	Coverage has lapsed — outreach required before next shipment
OK	No action needed at this time

Directory Structure

signal-cgm/
├── python-backend/
│   ├── core/
│   │   ├── coverage_calculator.py   # Coverage clock logic
│   │   ├── audit_logger.py          # PHI-safe audit logging
│   │   └── db_models.py             # PostgreSQL models
│   └── config/
│       └── payer_rules.json         # Wear-day rules by device and payer
├── n8n-workflows/                   # n8n batch trigger exports
└── CLAUDE.md                        # Active dev context

BAA Status (Level 1)

Vendor	BAA Required	Status
Hostinger VPS	Yes — PHI host	Pending
Anthropic API	Only if AI layer touches PHI	Not applicable (Level 1)
All other components	Self-hosted — operator is STTIL	N/A

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© 2026 STTIL Solutions LLC. Proprietary software — see LICENSE.md.