Prescription drug inflation, the CPI and GxRadar's generic index since 2014

In September 2026 the consumer price index for prescription drugs stood at 543.556, according to the Bureau of Labor Statistics' series CUUR0000SEMF01¹. That is 21.7 percent above its January 2014 level. Over the same span, the index for all items² that urban consumers buy rose 44.0 percent. GxRadar's index of what pharmacies pay for 43 common generics went the other way, falling 52.5 percent to 47.5.

Those three numbers measure different things. BLS's prescription drug index follows the price of a sampled prescription at a retail pharmacy, brand-name and generic alike, including what an insurer pays. The all-items CPI tracks the whole consumer basket. GxRadar's index follows only the invoice cost of old, multi-source generics, using federal survey data.

This piece explains what each one captures, sets them side by side since 2014, and shows where they split. Prescription prices have trailed general inflation over that time, and the generic shelf has deflated outright.

What the CPI prescription drug index measures

BLS publishes the series monthly on a 1982-84 base of 100, and it sits inside the medical care index³. A December 2021 BLS methodology report⁵ describes how it works. "The CPI collects transaction prices received by the retail pharmacy," the report says, and for an insured prescription the price "will include both the patient's copayment as well as the insurance reimbursed portion." Pharmacies are drawn from a panel of outlets, and five or six prescriptions are typically picked for pricing at each one. Internet and catalog channels that sell to U.S. consumers are eligible.

BLS calculates brand and generic sub-indexes but does not publish them. When a brand loses patent protection, the agency waits about six months and then redraws the sample between the brand and its new generics in proportion to recent sales, a step the report calls "redisaggregation." Consumers often switch faster than that, the report acknowledges, which means part of the drop that comes with generic entry may fall outside the index.

BLS's index also leaves out a growing share of drug spending. A 2022 National Bureau of Economic Research working paper⁶ noted that the CPI samples only retail outpatient outlets, so drugs dispensed in hospitals, clinics and physician offices are counted elsewhere in the medical CPI. The authors estimated that missing those specialty drugs led the index to understate overall drug price inflation by just under 75 basis points a year from 2010 to 2019.

What GxRadar's index measures

GxRadar's index uses the National Average Drug Acquisition Cost, a monthly survey of the invoice prices retail community pharmacies pay to buy drugs, published by CMS on data.medicaid.gov⁷ and described on the Medicaid NADAC page⁸. Under the NADAC methodology⁹, "discounts or rebates that are not reflected on the invoice at the drug line item level are not factored into the NADAC calculation." It is the pharmacy's acquisition cost, not what a customer pays at the counter.

Our basket holds 43 generics that had a NADAC price in January 2014, each fixed at one strength and form, such as the atorvastatin 20 mg tablet. The index is a geometric mean of each drug's price relative to January 2014, set to 100 at the start. No drug is ever added or dropped. GxRadar explains the construction in a separate methods piece, and the monthly figures are on the prices page.

For a sense of scale, 30 tablets of atorvastatin 20 mg cost pharmacies $5.31 in January 2014 (17.7 cents each) and 85 cents in October 2026 (2.8 cents each), by NADAC. The October 2026 index reading was 47.4, about 53 percent below the 2014 base and 1.7 points above its record low of 45.7 in December 2024.

The three lines since 2014

Each series below is rebased to January 2014 = 100. CPI figures are not seasonally adjusted, as published by BLS. The GxRadar column uses monthly NADAC averages.

From 2014 to 2017 the prescription drug CPI climbed 15 percent while the generic index fell 14 percent, a stretch that included the unwinding of the generic price spikes of 2013 to 2015. GxRadar covers that period in the generic price spikes and the long deflation that followed. From 2018 through 2021 the prescription index barely moved.

After that, the general CPI pulled away. All-items prices rose 20 percent from January 2022 to September 2026, according to BLS. The prescription index peaked at 572.748 in February 2025 and has slipped since. In the 12 months to September 2026 it fell 4.5 percent while the all-items index rose 3.7 percent. It declined in seven of the eight month-to-month changes in 2026. The generic index fell 9.3 percent over the same 12 months.

Adjusted for general inflation, the prescription drug CPI is about 15 percent below its 2014 level, and the generic basket's real decline is roughly two-thirds. Those are GxRadar's calculations from the published series, not BLS figures.

Why the measures disagree

Brand-name drugs carry most prescription spending even though generics fill most prescriptions. In Medicare Part D, generics were 12.5 percent of gross spending in 2024, according to the Medicare Payment Advisory Commission¹¹. An index of retail prescription prices will therefore move with brand pricing, and brand list prices often rise each year. HHS's planning office found that from January 2022 to January 2023 more than 4,200 drug products had list price increases, with an average increase of 15.2 percent, in its report on list price changes¹⁰. A list price is not a transaction price, and the CPI tracks transactions, but the direction of brand pricing pulls the index up in a way the generic basket never feels.

Generic prices, by contrast, are set by competition among many makers. Federal studies from FDA¹² and HHS¹³ found that generic prices fall steeply as competitors enter, and every drug in the GxRadar basket has had generics for years. GxRadar's piece on generic prices and the number of competitors sets those studies next to our own counts.

Units differ too. The CPI counts what the pharmacy receives for a prescription, which includes its dispensing margin. NADAC counts only what the pharmacy paid for the drug. A generic can fall to pennies on invoice while the price of the prescription, with the pharmacy's fee, moves far less. GxRadar explains how dispensing fees work and what NADAC leaves out.

A missing month in the federal series

The BLS tables have a hole. October 2025 shows no value for the prescription drug index, the all-items index or the medicinal drugs index⁴, marked "Data unavailable due to the 2025 lapse in appropriations." Any 12-month comparison that ends in October 2026 will need to skip it. As of Nov. 5, September 2026 is the latest month posted for all four BLS series used here. GxRadar's NADAC-based index updates monthly as CMS publishes each survey.