Senior citizens have saved $4 billion on prescription drugs since the Affordable Care Act was implemented, according to the Centers for Medicare & Medicaid Services. In the first half of this year alone, prescription savings for more than 1 million Medicare recipients totaled $687 million, the government claims. “Millions of people with Medicare have been paying less for prescription drugs, thanks to the healthcare law,” said Marilyn Tavenner, acting administrator of the Centers for Medicare & Medicaid Services, in a statement.