30-Month Stay: How Litigation Delays Generic Drug Approval

When a brand-name drug hits the market, it doesn’t just enjoy a monopoly because of its patent-it also gets a legal shield called the 30-month stay. This isn’t a loophole. It’s a rule baked into U.S. drug law since 1984, and it’s one of the biggest reasons why generic versions of life-saving medications often take years longer to reach patients-even after the patent expires.

What Exactly Is the 30-Month Stay?

The 30-month stay comes from the Hatch-Waxman Act, a law designed to balance two goals: letting generic drugs enter the market quickly to cut costs, while still protecting the original drugmakers’ investments. Here’s how it works in plain terms.

When a generic company wants to sell a cheaper version of a brand drug, they file what’s called an Abbreviated New Drug Application (ANDA) with the FDA. But if the brand drug is still under patent, the generic maker has to say so outright-this is called a Paragraph IV certification. It’s basically a legal challenge: "We think your patent is invalid, or we’re not infringing it."

Once they file that, they must notify the brand company. If the brand company sues within 45 days, the FDA is legally blocked from giving final approval to the generic drug for up to 30 months. That’s the stay. It doesn’t stop the FDA from reviewing the application. In fact, they often give what’s called "tentative approval"-meaning, "You passed all our tests. We’re just waiting on the courts."

So here’s the catch: the 30-month clock starts ticking the day the last patent holder gets the notice. But if the lawsuit drags on past 30 months? The stay can extend. Courts can shorten it. Sometimes, they do. Other times? The generic drug still can’t launch until the legal mess clears.

Why This Matters: The Real Delay Isn’t the 30 Months

Most people think the 30-month stay is the main reason generics are late. But data shows otherwise. According to a 2021 study from the University of Southern California, there’s a median gap of 3.2 years between when the 30-month stay ends and when the generic drug actually hits shelves.

So what’s happening in those extra years? It’s not the law holding things up-it’s business.

• Generic manufacturers need to ramp up production. Scaling from lab batches to millions of pills takes time.
• They often wait to launch until after the brand company’s exclusivity period ends, even if the patent is gone.
• Some companies delay launch to avoid price wars or to coordinate with other generics for maximum profit.

One regulatory affairs specialist at Teva told a pharmaceutical forum: "We’ve seen cases where the stay expired months ago, but the generic still didn’t launch because the commercial team wasn’t ready."

The FDA approved 1,046 ANDAs in 2022. Of those, 78% got tentative approval during patent litigation. That means the FDA was ready to go-long before the courts were.

How Patent Games Extend the Delay

The real problem isn’t the 30-month stay itself-it’s how brand companies use it.

Back in the 1990s, drugmakers listed an average of 1.2 patents per drug in the FDA’s Orange Book. By 2022? That number jumped to 8.3. Most of these aren’t core patents. They’re "secondary" patents-on things like pill coatings, dosing schedules, or delivery methods. These don’t protect the drug’s active ingredient. But under Hatch-Waxman, even a minor patent can trigger a 30-month stay.

A 2019 Brookings study found that 67% of patents listed for top-selling drugs were filed after the original drug was approved. This is called "patent evergreening." It’s legal. And it’s effective.

For example, a drug might have one patent on the molecule, then five more on how it’s taken, how it’s packaged, or what time of day it’s prescribed. Each one can be used to file a new lawsuit, restarting the clock. The 2003 Medicare Act tried to stop this by limiting brand companies to just one 30-month stay per ANDA. But it didn’t stop them from filing multiple lawsuits on different patents across different generic applicants.

That’s why some drugs face 10+ Paragraph IV challenges. The first generic to challenge wins 180 days of exclusive sales. That’s a $500 million prize. So companies race to be first. And brand companies? They respond with more lawsuits, more delays.

How It Compares to Other Countries

The U.S. is the only country with a system like this.

• In the European Union, generic companies can file for approval as soon as the patent expires. No stay. No lawsuit delay. Just regulatory review.
• Canada has a 24-month patent linkage system-shorter than the U.S., and it doesn’t automatically block approval.
• India and China don’t have stay mechanisms at all. Generics launch as soon as they’re approved.

As a result, when a drug loses patent protection in the U.S., generics take an average of 26 months longer to enter than in other wealthy countries, according to the FTC’s 2022 report.

That delay costs Americans billions. The FTC estimates patent litigation delays add $13.9 billion annually to U.S. drug costs. And it’s not just about price-it’s about access. Millions of people with diabetes, heart disease, or cancer wait longer for affordable versions of their meds.

Who Wins? Who Loses?

On one side: brand-name drugmakers. They say the 30-month stay is essential. Without it, they argue, no company would spend $2.6 billion to develop a new drug if generics could flood in the day after approval. Former FDA Commissioner Scott Gottlieb says the system has saved consumers $2.2 trillion since 1984.

But here’s the flip side: generic manufacturers spend $3-5 million per ANDA just on legal fees. A 2022 survey found 78% of generic companies say preparing for litigation adds 6-9 months to their development timelines. That money doesn’t go into making better drugs-it goes into lawyers.

And patients? They pay the price. A 2021 Harvard study found that for blockbuster drugs, the 30-month stay adds a median of 1.8 years to market exclusivity. That’s not patent protection. That’s extended monopoly.

Meanwhile, the top five generic manufacturers-Teva, Viatris, Sandoz, Hikma, and Sun Pharma-control nearly half the market. And 63% of ANDA applications now come from Indian and Chinese companies, who are more willing to fight the legal battles. That’s why U.S. drug prices haven’t dropped as fast as they should.

What’s Changing? And What Could Change Next

The system is under pressure.

In 2023, Congress introduced the Affordable Prescriptions for Patients Act. It proposes cutting the 30-month stay to 18 months and banning stays for secondary patents. The FDA also released draft guidance asking for clearer, more accurate patent listings in the Orange Book.

Industry analysts at Evaluate Pharma predict that if these reforms pass, $78 billion in branded drugs set to lose patent protection by 2028 could see generics enter 9-12 months faster. That could save consumers $195 billion.

But drugmakers aren’t backing down. PhRMA, the industry lobby, warns that weakening the stay could cut U.S. R&D investment by $14 billion a year and delay dozens of new drugs. The argument? Without protection, innovation dies.

The truth? The system was designed to balance innovation and access. But today, it leans too far toward the latter. And patients are paying the cost.

What You Should Know

• The 30-month stay doesn’t stop FDA review-it only blocks final approval.
• Tentative approval is common. It means the FDA is ready. The courts aren’t.
• Most delays happen after the stay ends-not during it.
• Secondary patents are the real delay engine.
• The U.S. is the only country with this system-and it’s the most expensive.

If you’re waiting for a generic version of your medication, don’t assume the patent expiration date is the launch date. It’s just the starting line. The race is still on.