Zerbaxa Generic: When Will Generic Ceftolozane and Tazobactam Be Available?
This page is aggregated from FDA records, court filings and company announcements. Coded and designed by Dr. Brian Staiger, PharmD, BCPS
Updated October 9, 2026 How we build our data
Zerbaxa Generic at a Glance
Four quick answers from FDA records and our estimate.
- When is the first generic expected? February 2036 About 9.5 years away Why then?
- Has the FDA approved a generic? Not yet None in the FDA’s records yet Why not yet?
- When does the brand’s protection end? February 2036 The last of 12 listed patents
- Can you buy a generic today? Not yet No company lists one for sale
Dr. Brian Staiger Explains
PharmD, BCPS · Clinical pharmacistGeneric ceftolozane and tazobactam is expected to be available in February 2036, about 9.5 years away. None is for sale yet.
Why February 2036?
It is when Zerbaxa’s patent 10,125,149 ends. That patent covers the product’s formulation, and once it ends, generics can go on sale as soon as the FDA approves them. We rate it toss-up: still unsettled. Just as likely to slip as to hold.
Why hasn’t the FDA approved a generic yet?
That is normal before a launch. The FDA usually can’t give a generic its final approval while a patent or exclusivity still blocks it, so final approval often comes close to the day the generic can be sold. No company holds a “tentative” approval yet either (the FDA’s word for a generic that is ready but still blocked).
Will the generic cost less?
Usually, but no company is recorded as having applied to make one yet, and a single company usually brings only a modest drop. See the price pattern
What should I do now?
Keep taking Zerbaxa as prescribed. When a generic arrives, your pharmacy may switch you to it automatically, and it may look different. What a generic means for you
Our month is only an estimate based on available information, so we never name a day.
Zerbaxa by the Numbers
- Reason
- Patent expiresA patent that protects the brand runs out. After that, approved generics can be sold.
- How sure
- Toss-up Still unsettled. Just as likely to slip as to hold.
- Price competition
- None filed yet No filers on record
- Brand sales
- $204M a yearBig seller
- FDA approved 2014 December 2014 FDA Orange Book
- Patents listed 12 last runs to February 2036 FDA Orange Book
- Medicare Part D spent $24.9M in 2025, for 1,422 people CMS Part D Spending by Drug
- Medicaid prescriptions 2,396 in the last four reported quarters, $6.4M CMS Medicaid drug utilization, to Q1 2026
Zerbaxa’s Road to a Generic
Zerbaxa has had the market to itself since the FDA approved it in December 2014 (Cubist Pharmaceuticals LLC). Its FDA protection (pediatric) runs to November 2029. Its 12 listed patents run to February 2036.
The first generic of Zerbaxa is expected in February 2036.
Why that month: patent 10,125,149, on the product’s formulation, ends then.
Each bar runs from the brand’s approval to the day that protection ends. The green band is our projection for the first generic: a month, never a day, because legal dates move and a generic reaches shelves days to weeks after it is allowed. Sources: FDA Orange Book; the expected month from court records and company announcements.
Zerbaxa Patents and FDA Protections
Every patent and exclusivity the FDA Orange Book lists for Zerbaxa’s own applications. A protection running past the expected month does not mean the date is wrong: a settlement or a court ruling can let a generic in before a patent ends, and a patent on one formulation or use does not block every generic.
The one that matters for a generic launch: patent 10,125,149, which ends in February 2036, the month the first generic is expected.
| Patent | What it covers | Protects until | Status |
|---|---|---|---|
| 7,129,232 | The active ingredient; the product’s formulation; a way of using it (U-36, U-1676, U-3361, U-3360, U-4550, U-4547, U-4542, U-4543) | November 2028 with the pediatric extension | Active |
| 9,724,353 | A way of using it (U-2565, U-2566, U-4542, U-4543) | March 2033 with the pediatric extension | Active |
| 10,028,963 | A way of using it (U-2566, U-2565, U-4542, U-4543) | March 2033 with the pediatric extension | Active |
| 8,968,753 | A way of using it (U-1673, U-1672, U-3361, U-3360, U-4550, U-4547) | September 2034 with the pediatric extension | Active |
| 9,320,740 | The product’s formulation | September 2034 with the pediatric extension | Active |
| 9,872,906 | The product’s formulation | September 2034 with the pediatric extension | Active |
| 10,420,841 | A way of using it (U-2631, U-1672, U-3361, U-3360, U-4546, U-4547) | September 2034 with the pediatric extension | Active |
| 11,278,622 | A way of using it (U-3335, U-3336, U-4542, U-4543) | September 2034 with the pediatric extension | Active |
| 8,906,898 | The active ingredient; the product’s formulation | November 2034 with the pediatric extension | Active |
| 10,376,496 | A way of using it (U-2611, U-2610, U-4548, U-4549) | March 2035 with the pediatric extension | Active |
| 10,933,053 | A way of using it (U-3091, U-3090, U-4544, U-4545) | March 2035 with the pediatric extension | Active |
| 10,125,149 Sets the expected month of generic availability | The product’s formulation | February 2036 with the pediatric extension | Active |
| Exclusivity | What it means | Ends | Status |
|---|---|---|---|
| New patient population NPP | Three years of protection for a newly approved group of patients. | May 2029 | Active |
| Pediatric PED | Six more months, earned by studying the medicine in children. | November 2029 | Active |
Source: FDA Orange Book, application 206829. Patent numbers open the patent on Google Patents.
Who Is Lined Up to Make Generic Ceftolozane and Tazobactam
Three steps stand between a brand and a generic you can buy: a company applies to the FDA, the FDA approves it, and the company starts selling it.
Applied to the FDA
No company is recorded as having applied to the FDA to make a generic Zerbaxa yet.
Approved by the FDA
Not yet. The FDA has not approved a generic ceftolozane and tazobactam. Final approval often comes close to the day a generic can be sold.
For sale in pharmacies
Not yet. No company lists a generic ceftolozane and tazobactam for sale with the FDA.
Sources: how many companies have applied, from court records and company announcements; approved generics from the FDA Orange Book; tentative approvals from Drugs@FDA; what is for sale from the FDA NDC Directory. The FDA does not disclose an application before it approves it (21 CFR 314.430).
Zerbaxa Price: What Pharmacies Pay and What Generics Usually Do
What a Generic Could Cost
How we estimate it. The national survey of what pharmacies pay (NADAC) has no recent price for Zerbaxa, so we cannot show dollars. Here is the FDA’s finding of how far the price pharmacies pay usually falls as generic companies join: about 31% with one company, 44% with two, 73% with four and over 95% with six or more (the typical drop for every drug whose first generic came out from 2015 to 2017).
Median prices pharmacies paid for the generic (invoice prices), compared with the brand’s price before generic entry, from FDA’s 2019 analysis “Generic Competition and Drug Prices”. At the manufacturer’s price FDA found steeper drops (about 39%, 54%, 79% and over 95%), the figures quoted elsewhere on this tracker. A typical pattern, not a price quote for this medicine.
What Medicare and Medicaid Spend on Zerbaxa
Big public spending is part of why generic makers line up for a medicine, and why its first generic matters beyond the pharmacy counter. Figures are before manufacturer rebates, which are confidential.
Medicare Part D spending
What Medicare drug plans spent on Zerbaxa, before manufacturer rebates.
- $6.1M
- January to March 2026, the latest CMS has posted
For 406 people, about $4,380 per prescription fill - $24.9M
- 2025, the whole year
For 1,422 people, about $3,953 per prescription fill
See the numbers
| Period | Spending | People | Per fill |
|---|---|---|---|
| January to March 2026 | $6,105,505 | 406 | $4,379.85 |
| 2025 | $24,909,546 | 1,422 | $3,953.27 |
Source: CMS Medicare Part D Spending by Drug, matched by the brand name Zerbaxa only, so no generic is counted in it. What CMS says it is used for: Ceftolozane/tazobactam is used to treat a variety of bacterial infections. It is a cephalosporin antibiotic.
Medicaid prescriptions by quarter
2,396 prescriptions in the four quarters to Q1 2026, $6.4M paid.
See the numbers
| Quarter | Prescriptions | Medicaid paid |
|---|---|---|
| Q1 2026 | 485 | $1,449,585 |
| Q4 2025 | 473 | $1,594,531 |
| Q3 2025 | 750 | $1,780,017 |
| Q2 2025 | 688 | $1,573,069 |
| Q1 2025 | 746 | $1,406,984 |
Source: CMS Medicaid State Drug Utilization Data, over Zerbaxa’s own package codes.
Zerbaxa Strengths and Forms
| Strength | Form | How it is taken | Approved | Status |
|---|---|---|---|---|
| EQ 1GM BASE/VIAL;EQ 0.5GM BASE/VIAL | Powder | Intravenous | December 2014 | Prescription reference product |
Source: FDA Orange Book, Cubist Pharmaceuticals LLC. Listed for sale today by Merck Sharp & Dohme LLC (FDA NDC Directory).
Zerbaxa NDC Codes and Packages
Each Zerbaxa package sold today has its own NDC, the product number printed on the box and on the pharmacy label. Open one to see that package’s details, what pharmacies pay for it and its patent timeline.
| NDC | Product | Package | Company |
|---|---|---|---|
| 67919-0030-01 | CEFTOLOZANE SULFATE 1 g/10mL / TAZOBACTAM SODIUM .5 g/10mL injection, powder, lyophilized, for solution | carton of 10 vials of 10 mL | Merck Sharp & Dohme LLC |
| 67919-0030-01 | CEFTOLOZANE SULFATE 1 g/10mL / TAZOBACTAM SODIUM .5 g/10mL injection, powder, lyophilized, for solution | carton of 10 vials of 10 mL | Merck Sharp & Dohme LLC |
Source: the FDA NDC Directory, current listings only. Only packages sold under Zerbaxa’s own FDA approval (NDA 206829) are listed, never a generic. Some codes belong to companies that repackage Zerbaxa: it is the same medicine in a different package.
What a Generic Zerbaxa Means for You
Nothing changes until it is in pharmacies
Until a generic is actually for sale, keep filling Zerbaxa as usual. When one arrives, there is nothing you need to sign up for.
Your pharmacy may switch you automatically
Every state lets pharmacists fill a brand-name prescription with an FDA-approved generic rated as equivalent to it, and about 19 states require them to, unless your prescriber writes “dispense as written” or “brand medically necessary” on the prescription. Some states ask the pharmacist to tell you, or to get your OK first. A study of every state’s law has the details.
It will probably look different
US trademark law does not let a generic look exactly like the brand, so the color, shape or markings usually change. The active ingredient, strength and form are the same. An “authorized generic,” made by or for the brand’s own company, can look identical. The FDA explains.
Your insurance may change too
Once a lower-cost version is available, many insurance plans charge more for the brand, or stop covering it. Your plan’s drug list (formulary) says how.
Until a generic is on US pharmacy shelves, be careful with websites that offer “generic Zerbaxa”. The FDA warns that unlicensed online pharmacies sell counterfeit and unapproved medicines; its BeSafeRx page shows how to check a pharmacy.
Questions people ask about Zerbaxa
Is there a generic for Zerbaxa right now?
No. As of October 9, 2026 no generic ceftolozane and tazobactam is listed for sale in the FDA NDC Directory.
When will Zerbaxa go generic?
February 2036 is the expected month, and that is toss-up but not certain. It is when Zerbaxa’s patent 10,125,149 ends. That patent covers the product’s formulation, and once it ends, generics can go on sale as soon as the FDA approves them.
Will generic ceftolozane and tazobactam be the same as Zerbaxa?
Yes in the ways that matter: the same active ingredient, strength and form, with proof that it reaches your blood the same way. Inactive ingredients can differ, which is why some people notice a different look or taste.
How much will the generic cost?
Nobody can say for sure before launch. No company is recorded as having applied to the FDA to make one yet, and a single company usually brings only a modest drop.
Has the FDA approved a generic Zerbaxa?
Not yet. The FDA Orange Book lists no approved generic version of Zerbaxa.
When does the Zerbaxa patent expire?
The FDA Orange Book lists 12 patents for Zerbaxa; the last runs to February 2036, counting a six-month pediatric extension. The one behind the expected month is patent 10,125,149, which ends in February 2036. A patent date is not the launch date: settlements and court rulings often bring a generic earlier, and FDA approval or a company’s own plans can make it later. The expected month on this page (February 2036) weighs all of that.
Changes to This Projection
- First generic expected February 2036 on this month’s schedule. A line is added here whenever a monthly update moves the month, the reason or how sure it is.
Every change to the expected month is logged here with the month we saw it.
Also Going Generic
- VumerityDiroximel FumarateDuring 2033
- EmblaveoAvibactam and AztreonamFebruary 2033
- JesduvroqDaprodustatDecember 2033
- OnpattroPatisiran SodiumAugust 2035
- SotyktuDeucravacitinibSeptember 2036
- AristadaAripiprazole LauroxilApril 2039
About Zerbaxa
- Generic name ceftolozane and tazobactam
- How it is taken Into a vein (IV)
- Company Cubist Pharmaceuticals LLC
- More drugs Brand-name drugs starting with Z
- Have a question? A pharmacist answers, free. Ask about Zerbaxa
Sources. The expected month: FDA Paragraph IV Patent Certifications list, federal court records, company announcements and securities filings (settlement dates, launch plans, sales). The record on this page: FDA Orange Book, Drugs@FDA (tentative approvals), FDA NDC Directory, CMS Medicare Part D Spending by Drug, Medicaid State Drug Utilization Data, FDA, Generic Competition and Drug Prices (2019). Updated October 9, 2026. Information, not medical advice.