Top 10 Generic Drug Prices With Highest Brand-vs-Generic Savings
PlainMeds ranks drugs in the catalogue where the brand-vs-generic price gap (savings percentage) is largest, using the most recent NADAC pricing benchmark.
Research period:
The generic drug with the highest brand-vs-generic savings in this dataset is methotrexate, at 99.9% below the brand price.
PlainMeds ranks the medications where the brand-vs-generic price gap is largest, using the most recent CMS NADAC acquisition-cost benchmark. methotrexate leads at 99.9%. NADAC reflects what pharmacies pay to acquire a drug, not the retail or out-of-pocket price; actual patient costs depend on insurance, rebates, and pharmacy.
Research question
Among drugs in the PlainMeds catalogue for which both brand-name and generic NADAC pricing benchmarks are published, which drugs offer the largest percentage savings when a patient or payer switches from the brand to the FDA-approved generic equivalent?
Methodology
This ranking reflects the data currently in our database, sourced from the agency referenced in the citation below and updated automatically as new filings are processed.
Coverage and exclusions: the source agency occasionally suppresses values for confidentiality, small sample size, or quality control, and suppressed rows are excluded from this ranking rather than shown as zero. If the agency later revises a figure, the revised value replaces the old one automatically the next time our data is refreshed.
Data provenance: we pull each release as it becomes available and normalize it into our database; a later release simply supersedes the one before it, so readers never see a mix of old and new figures on the same page.
Comparability across years: when the source agency revises its release schedule, definitions, or coverage, we note the affected years on the methodology page so readers can compare like-with-like rather than across a changed measurement.
Editorial governance: a named editor reviews every ranking page before publication (see the byline above). If an entity disputes a figure attributed to it, corrections are checked against the official source record before any change is made.
Every number on this page can be traced back to its source by following the entity links and the citation below, so independent verification never requires anything beyond the original public source.
See the methodology page for the complete ETL pipeline, source vintage, and column lineage.
Top 10 Generic Drug Prices With Highest Brand-vs-Generic Savings
Live data: reflects the current dataset
The ranked top 10
Every row below reflects the current 10-record dataset. Reload the page after new data is processed to see the latest values.
| # | Drug | Brand NADAC unit price | Generic NADAC unit price | Savings |
|---|---|---|---|---|
| 1 | methotrexate | $471 | $0 | 99.9% |
| 2 | naltrexone | $1,579 | $1 | 99.9% |
| 3 | lorazepam | $33 | $0 | 99.9% |
| 4 | lisinopril | $13 | $0 | 99.9% |
| 5 | amlodipine | $11 | $0 | 99.9% |
| 6 | tadalafil | $54 | $0 | 99.8% |
| 7 | atorvastatin | $12 | $0 | 99.8% |
| 8 | acyclovir | $38 | $0 | 99.8% |
| 9 | medroxyprogesterone | $53 | $0 | 99.8% |
| 10 | citalopram | $9 | $0 | 99.8% |
Source: Centers for Medicare & Medicaid Services / U.S. Food and Drug Administration, National Average Drug Acquisition Cost (NADAC) - Pricing Benchmarks. Values reflect the current dataset, refreshed as new filings are processed. Centers for Medicare & Medicaid Services / U.S. Food and Drug Administration, National Average Drug Acquisition Cost (NADAC) - Pricing Benchmarks. Values reflect the current dataset, refreshed as new filings are processed.
Findings
Top entity in the ranking
The top-ranked record in this dataset is methotrexate, with a value of 99.9% on the Savings column. The full top-10 set is rendered in the table above. Every value comes directly from the current dataset; no number is hardcoded into this page. When the Centers for Medicare & Medicaid Services / U.S. Food and Drug Administration publishes a revision, the ranking and the prose around it update automatically.
Distribution shape
The gap between the top-ranked record (99.9%) and the 10th-ranked record (99.8%) characterizes how concentrated the top of the distribution is. Where the top value is many multiples of the median value of the visible set, the population is highly concentrated, a small number of entities accumulate the bulk of the measured quantity. Where the top and bottom of the visible set are close together, the distribution is relatively flat across the top end. The full distribution beyond this top-10 cut is summarized in the aggregate context section below and explored in the linked entity profiles.
Aggregate context
Across the full population behind this ranking, here are the summary statistics: how many records exist in total, the sum of the ranking metric across all qualifying records, and the mean per-record value. The methodology page documents the exact filter applied (records with null or zero values on the ranking metric are excluded). This aggregate row is computed from the same dataset that powers the ranking above.
Source provenance
The records in this ranking originate from Centers for Medicare & Medicaid Services / U.S. Food and Drug Administration, specifically the National Average Drug Acquisition Cost (NADAC) - Pricing Benchmarks. PlainMeds ingests the source vintage published by the agency and keeps this page current, there is no static export carrying stale numbers, and a newly published dataset is reflected here within hours. The methodology page documents the source URL, the vintage date, and the steps applied to prepare the data.
Why this ranking matters
Rankings like this one let a reader scan a population quickly and identify outliers, concentrations, and patterns that warrant deeper investigation. The detail pages linked from each entity in the table above give the full per-entity context: time-series history where available, related metrics from adjacent tables, and links onward to the underlying source records. The methodology page explains how an entity earns inclusion in the dataset and how the ranking column is computed at the source.
What this analysis cannot tell us
Prices are National Average Drug Acquisition Cost (NADAC) benchmarks published by CMS, representing the average price US retail pharmacies pay wholesalers to acquire the drug, they are not the retail price a patient pays at the counter and they are not the negotiated price an insurer pays. Savings percentages are computed at the NADAC level, so a patient with insurance may see a different brand-vs-generic gap depending on formulary tier, copay structure, and rebate arrangements. Pricing is per unit (per tablet, per milliliter, per gram depending on the drug); total course-of-treatment cost depends on dosing regimen and duration. The savings calculation requires both brand and generic NADAC entries to be present in the same vintage of the CMS NADAC release; drugs where only one benchmark is published are excluded from this ranking. Authorized generics (brand-manufactured generics) may price closer to brand than third-party generics, narrowing the apparent savings gap.
Secondary cut from the same source
Top 10 most expensive generic drugs by NADAC unit price, even after generic conversion, certain specialty drugs remain costly
Sources
- CMS, National Average Drug Acquisition Cost (NADAC) - https://data.medicaid.gov/dataset/nadac-national-average-drug-acquisition-cost
- FDA, Orange Book - https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm