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Variation in Medicare Part D and Part B drug spending among older adults with Alzheimer's disease and related dementias
Jang S, Chen J. Innovation in Aging, 2026-08-03
Topic: Risk, prevention and care in population studies
Background and objectives This study examined Medicare Part D and Part B drug spending and beneficiary out-of-pocket (OOP) costs among community-dwelling Medicare fee-for-service (FFS) beneficiaries with Alzheimer's disease and related dementias (ADRD), assessing variation by dual eligibility, state, and Accountable Care Organization (ACO) enrollment. Research design and methods We conducted a cross-sectional analysis using the 2022 Medicare Beneficiary Summary File linked to the Cost and Use file. The sample included 1 372 696 community-dwelling Medicare FFS beneficiaries with ADRD, including 575 308 beneficiaries with five or more chronic conditions. Outcomes included annual Medicare payments and beneficiary OOP costs for Parts D and B drugs. Analyses were stratified by dual eligibility duration, state, and ACO enrollment, with adjusted estimates from generalized linear models. Results Medicare Part D drug spending was substantial, increasing with dual-eligibility duration: $8732-$9107 among beneficiaries with full-year dual eligibility and exceeding $11 500 among those with 5+ chronic conditions. Beneficiary OOP costs were highest among Medicare-only beneficiaries and markedly lower among dually eligible individuals. Medicare Part B drug spending was highest among Medicare-only beneficiaries and varied widely by state, ranging from $433 to $1827 among Medicare-only beneficiaries and from $179 to $1446 among dually eligible beneficiaries. After adjustment, differences in Parts D and B drug spending by ACO enrollment were modest. Discussion and implications Parts D and B drug costs among Medicare beneficiaries with ADRD vary by dual eligibility and geography. Limited associations with ACO enrollment underscore the need for better medication management integration in value-based care for high-need older adults with ADRD.
Key findings
- Results Medicare Part D drug spending was substantial, increasing with dual-eligibility duration: $8732-$9107 among beneficiaries with full-year dual eligibility and exceeding $11 500 among those with 5+ chronic conditions.
Why it matters
This cross-sectional analysis of 1,372,696 community-dwelling Medicare fee-for-service beneficiaries with Alzheimer's disease and related dementias found substantial Medicare Part D drug spending that increased with dual-eligibility duration, exceeding $11,500 among those with five or more chronic conditions. It describes drug spending and out-of-pocket cost variation rather than any treatment, cure, or prevention.
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Study details
- Study designcross-sectional
- Participants1,372,696
- Effect sizePart D spending $8,732-$9,107 (full-year dual eligibles) vs >$11,500 with 5+ chronic conditions; Part B drug spending varied $433-$1,827 by state
- Evidence strengthModerate
Limitations
Only Medicare-covered spending is observed, so Medicaid payments and non-covered services are missed, understating total medication costs for dual eligibles; CMS risk-adjustment scores were not incorporated; the analysis focuses on beneficiaries attributed to Medicare Shared Savings Program ACOs and may not generalise to Medicare Advantage; low-income subsidy enrolment, benefit design, income and dementia severity were not directly measured.
How this study scored 44/100
Published in a peer-reviewed journal, and it is a snapshot of people at one point in time. Scored zero for randomised / blinded because the record does not state it. We have no data on senior author's track record and free to read, so those were left out: it earned 41 of the 94 points we could judge it on, which is 44 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Innovation in Aging) |
| Journal's citation record | 0 / 4 | Innovation in Aging: journal h-index 48 (OpenAlex, 2026-10-29) |
| Study design | 4 / 12 | A snapshot of people at one point in time |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 5 / 5 | 2026 — within 1 year(s) of the newest study here |
| Sample size | 4 / 4 | 1,372,696 participants |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 0 / 7 | Cited 0 times (OpenAlex, 2026-10-10) |
| Citations per year | 0 / 5 | 0.0 citations a year over 2 year(s) since 2026 |
| Impact for its field and year | 0 / 6 | Cited 0.0× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 0 / 4 | Cited 0 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | — / 4 | OpenAlex's profile for last-listed author Jie Chen holds only 8 work(s), too few to judge a track record — left out of this score |
| Institution's track record | 1 / 3 | University of Maryland, College Park: institution h-index 1,338 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 42787606) |
| Free to read | — / 2 | Access not recorded — left out of this score |
| Points | 41 / 94 | Scored on 18 of 20 parts. We have no data for the rest, so they are left out: 41 of the 94 points we could judge it on is 44 out of 100. |
| Total | 44 / 100 | — |
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Read the original
Full text: free to read — PubMed Central lists this copy as free to read: the link above (checked 10 Oct 2026).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Jang, S., & Chen, J. (2026). Variation in Medicare Part D and Part B drug spending among older adults with Alzheimer's disease and related dementias. Innovation in Aging. https://doi.org/10.1093/geroni/igag085
Vancouver
Jang S, Chen J. Variation in Medicare Part D and Part B drug spending among older adults with Alzheimer's disease and related dementias. Innovation in Aging. 2026. doi:10.1093/geroni/igag085. PMID: 42787606.
BibTeX
@article{jang2026-42787606,
author = {Jang, S. and Chen, J.},
title = {{Variation in Medicare Part D and Part B drug spending among older adults with Alzheimer's disease and related dementias}},
journal = {Innovation in Aging},
year = {2026},
doi = {10.1093/geroni/igag085},
pmid = {42787606},
url = {https://doi.org/10.1093/geroni/igag085}
}
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