10 Top-Selling Drugs Accounted for 22% of Medicare Part D Spending

The ten top-selling prescription drugs accounted for more than 20 percent of total gross Medicare Part D spending in 2021, a KFF analysis revealed.

Under the Inflation Reduction Act’s Medicare drug price negotiation program, an initial ten drugs will be selected for price negotiation for 2026, with this number increasing each year.

The drugs must be single-source brand-name drugs or biological products without generic or biosimilar alternatives. Additionally, they must be at least seven or 11 years past their FDA approval or licensure date, depending on if they are a small-molecule drug or a biologic.

KFF used 2021 Medicare Part D spending data from CMS to contextualize the potential impact of negotiating drug prices.

Medicare Part D covered more than 3,500 prescription drug products in 2021. Total gross spending hit $216 billion before accounting for rebates paid by drug manufacturers to pharmacy benefit managers (PBMs).

The ten top-selling drugs accounted for 0.3 percent of covered drugs and 22 percent of the total gross spending or $48 billion in 2021, the analysis found. The top 100 drugs accounted for 3 percent of covered drugs and 61 percent of total gross spending ($131 billion).

Among the top ten drugs, total gross spending ranged from $2.6 billion to $12.6 billion.

Ozempic, a diabetes drug, accounted for $2.6 billion. The drug has recently gained popularity as it can aid in weight loss, but Medicare only covers it when prescribed for diabetes treatment. In addition to Ozempic, four other of the top ten drugs in 2021 were diabetes drugs, including Trulicity ($4.7 billion), Januvia ($4.1 billion), Jardiance ($3.7 billion), and Lantus Solostar ($2.8 billion).

At the high end, gross spending totaled $12.6 billion for Eliquis, a blood thinner manufactured by Bristol Myers Squibb. Gross spending also surpassed $5 billion for Xarelto ($5.2 billion), a blood thinner manufactured by Janssen, and Revlimid ($5.9 billion), a treatment for multiple myeloma manufactured by Bristol Myers Squibb.

Imbruvica, a cancer treatment from Pharmacyclics, accounted for $3.2 billion of total gross Medicare spending, while Humira Citrate-free (Cf) pen, a rheumatoid arthritis treatment manufactured by AbbVie, represented $2.9 billion.

Overall gross spending on the ten top-selling drugs grew from $22 billion in 2018 to $48 billion in 2021. This spending increase accounted for more than half of the increase in gross Medicare spending across all covered Part D drugs, which rose from $166 billion to $216 billion.

Between 2018 and 2021, Part D spending on Eliquis increased by 2.5 times, spending on Trulicity more than tripled, and spending on Jardiance grew more than five times.

As CMS develops its list of the ten drugs that will be eligible for price negotiation in 2026, the KFF data reveals that two of the ten top-selling drugs in 2021 will not be eligible for selection due to their approval dates: Trulicity and Ozempic. Furthermore, three drugs will not be eligible based on generic or biosimilar availability in 2023: Revlimid, Humira, and Lantus.

“While all of the 10 top-selling Part D drugs in 2021 will not be included on the list of 10 drugs selected for price negotiation this year, this analysis suggests that targeting negotiation on a small number of high-spending drugs could affect a disproportionate share of Medicare drug spending in the future,” KFF wrote.