part-d-cap

Project month-by-month Medicare Part D out-of-pocket spending against the statutory annual cap, identify the month the cap is reached, quantify what the cap itself saves, and compare normal payment timing against the Medicare Prescription Payment Plan — which spreads the SAME total across the year without reducing it. Supports plan years 2026 and 2027 and fails closed to 2026 for any unsupported year rather than extrapolating. This is a standard-benefit simulation, NOT a plan-specific pharmacy quote: plan negotiated prices and plan cost sharing are not held and are never inferred.

{'type': 'object', 'required': ['monthly'], 'properties': {'drug': {'type': 'string', 'description': 'Optional drug name — checks formulary status and whether spending on it counts toward the cap'}, 'join': {'type': 'string', 'description': 'Optional month (1-12) the payment plan would be joined'}, 'year': {'type': 'string', 'description': 'Optional plan year: 2026 or 2027'}, 'monthly': {'type': 'string', 'description': 'Expected monthly out-of-pocket spend on covered drugs, in USD, e.g. "300"'}, 'deductible': {'type': 'string', 'description': 'Optional plan drug deductible in USD, e.g. "615" or "0"'}}}