Cai Christopher L, Bhaskar Anushka, Kesselheim Aaron S, Rome Benjamin N
Program On Regulation, Therapeutics, And Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
JAMA Intern Med. 2025 Aug 18. doi: 10.1001/jamainternmed.2025.4003.
The Inflation Reduction Act (IRA) included several changes to Medicare Part D prescription drug coverage effective in 2024 and 2025, including a $2000 annual out-of-pocket limit and the shifting of spending from the government to plan sponsors. Federal policies prevented premium increases in 2025, but Part D plans may have responded by increasing deductibles or medication cost sharing.
To measure annual changes in Medicare Part D premiums, deductibles, and cost sharing from 2019 to 2025.
DESIGN, SETTING, AND PARTICIPANTS: This serial cross-sectional study included 2019 to 2025 data for enrollees in Medicare Part D stand-alone and Medicare Advantage plans.
The primary outcomes were mean monthly premiums and annual deductibles, as well as the proportion of enrollees with coinsurance (vs co-payments) for medications in different formulary tiers. To illustrate changes, mean monthly out-of-pocket costs were estimated for 9 high-spending, nonspecialty, brand-name medications. Results were weighted by plan enrollment and stratified by stand-alone vs Medicare Advantage plans.
For Medicare Advantage plans, mean deductibles decreased from $153 in 2019 to $66 in 2024, then increased to $228 in 2025. The proportion of Medicare Advantage beneficiaries with coinsurance for preferred brand-name drugs ranged from 0.8% to 2.5% from 2019 to 2024 and increased to 27.7% in 2025. For 9 high-spending, nonspecialty, brand-name drugs, mean monthly out-of-pocket costs ranged from $46 to $55 from 2019 to 2024 and increased to $73 in 2025. In stand-alone plans, changes were observed before and after implementation of the IRA: mean deductibles increased steadily from $295 in 2019 to $490 in 2025, and the proportion of beneficiaries with coinsurance for preferred brand-name drugs increased from 21.9% to 84.0%. Cost sharing for the 9 drugs increased steadily from $62 in 2019 to $108 in 2025 in stand-alone plans. Premiums for both plan types decreased throughout the study period.
This cross-sectional study demonstrates that as the IRA's changes to Part D were implemented in 2024 to 2025, there were concurrent changes in plan design that may increase cost sharing, particularly for beneficiaries who do not spend more than the $2000 annual out-of-pocket limit and for those in Medicare Advantage plans. Additional policies may be needed to address cost sharing and ensure the affordability of essential medications covered by Medicare Part D.
《降低通胀法案》（IRA）对医疗保险D部分的处方药覆盖范围进行了多项调整，于2024年和2025年生效，包括每年2000美元的自付费用上限以及支出从政府向计划赞助商的转移。联邦政策在2025年阻止了保费上涨，但D部分计划可能通过提高免赔额或药物费用分担来做出回应。
衡量2019年至2025年医疗保险D部分保费、免赔额和费用分担的年度变化。
设计、设置和参与者：这项系列横断面研究纳入了2019年至2025年医疗保险D部分独立计划和医疗保险优势计划参保者的数据。
主要结局为平均月度保费和年度免赔额，以及不同处方层级中采用共保（相对于共付）方式支付药物费用的参保者比例。为说明变化情况，估算了9种高支出、非专科、品牌药的平均月度自付费用。结果按计划参保人数加权，并按独立计划与医疗保险优势计划分层。
对于医疗保险优势计划，平均免赔额从2019年的153美元降至2024年的66美元，然后在2025年增至228美元。2019年至2024年，医疗保险优势计划中优先品牌药采用共保方式的受益人的比例为0.8%至2.5%，2025年增至27.7%。对于9种高支出、非专科、品牌药，2019年至2024年平均月度自付费用为46美元至55美元，2025年增至73美元。在独立计划中，在《降低通胀法案》实施前后观察到了变化：平均免赔额从2019年的295美元稳步增至2025年的490美元，优先品牌药采用共保方式的受益人的比例从21.9%增至84.0%。在独立计划中，这9种药物的费用分担从2019年的62美元稳步增至2025年的108美元。在整个研究期间，两种计划类型的保费均下降。
这项横断面研究表明，随着2024年至2025年《降低通胀法案》对D部分的调整得以实施，计划设计同时发生了变化，这可能会增加费用分担，特别是对于那些年度自付费用不超过2000美元的受益人以及医疗保险优势计划的参保者。可能需要额外的政策来解决费用分担问题，并确保医疗保险D部分涵盖的基本药物的可负担性。
