Paragraph IV: What It Means for Generic Drug Access and Lower Prices

When a brand-name drug’s patent is about to expire, Paragraph IV, a provision under the Hatch-Waxman Act that allows generic drug companies to challenge existing patents before they expire. Also known as a Paragraph IV certification, it’s the legal tool that lets generics enter the market early—often slashing prices by 80% or more. This isn’t just a paperwork step. It’s the main reason you can buy metformin, lisinopril, or atorvastatin for pennies today instead of hundreds of dollars.

Here’s how it works: A generic company files an ANDA, an Abbreviated New Drug Application submitted to the FDA to prove a generic version is bioequivalent to the brand. If they believe the brand’s patent is invalid, unenforceable, or won’t be infringed, they file a Paragraph IV certification, a legal notice that directly challenges the patent. The brand-name company then has 45 days to sue. If they do, the FDA can delay generic approval for up to 30 months—but that clock often runs out before the case is settled, letting the generic launch anyway. This is why you see multiple generic versions of the same drug hit the market all at once. It’s not luck—it’s the result of companies betting on weak patents.

That’s why so many posts here talk about generic drug entry, pricing, and alternatives. When a drug like Augmentin or Propecia loses patent protection, Paragraph IV is the engine behind the flood of cheaper options. It’s also why some generics are called "authorized generics"—they’re made by the brand itself, just sold under a different label to compete with other generics. And when you see articles about predicting when your medication will go generic, they’re tracking Paragraph IV filings like stock market indicators.

But it’s not perfect. Big pharma often uses tactics like "evergreening"—making tiny changes to a drug to get new patents—just to delay Paragraph IV challenges. Some lawsuits drag on for years, keeping prices high. But when it works, Paragraph IV saves patients and insurers billions. It’s why your insulin, your blood pressure pill, or your antidepressant might cost less than your coffee this week.

Below, you’ll find real-world examples of how Paragraph IV shapes what’s on your pharmacy shelf—from the timing of generic launches to how lawsuits affect availability. Whether you’re trying to save money, understand why your prescription changed, or just want to know how the system works, these posts cut through the noise and show you what actually happens behind the scenes.