MEDICINE AND PUBLIC ISSUES Prescription Prices Under the New York Generic Substitution Law

This law mandates substitution of a less expensive product if the physician signs the prescription for an eligible brand name drug on the line marked "substitution permissible. " We purchased drugs by brand name and generically before the law went into effect. Later, we purchased the same drugs in the same stores using the formats "brand-dispense-as-written/ ' "brand-substitution-permissible/ ' and "generic. " Mean savings from generic prescribing or substitution increased from 1 2. 1 % ± 20.4 % before the law to 26.2 % ± 10.5% (brand-substitution-permissible) and 2 7. 2 % + 14.2% (generic). Prices for the same drug written the same way varied enormously among pharmacies. Brand-dispense-as-written, brand-substitution-permissible, and generic prices in the same store varied substantially an