Plena Health is an AI operating system for specialty medical practices that automates administrative workflows including referrals, fax intake, scheduling, procedure compliance, and collections across a practice's existing systems. The platform integrates with current infrastructure rather than requiring migration to new software. The company reports growing 17x over ten months and crossing seven figures in committed ARR, with reach across six specialties in eight states. Plena Health is part of Y Combinator's Spring 2026 batch.