{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T01:19:39Z","timestamp":1787707179652,"version":"build-2784847793"},"reference-count":22,"publisher":"Wiley","issue":"5","license":[{"start":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T00:00:00Z","timestamp":1787616000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T00:00:00Z","timestamp":1787616000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/100014848","name":"Arnold Ventures","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100014848","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Health Services Research"],"published-print":{"date-parts":[[2026,10]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To estimate the extent to which Medicare Advantage (MA) plans underestimate risk, the additional Part A and Part B (A&amp;B) revenue insurers receive as a result, and how this differs across insurers and over time.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Study Setting and Design<\/jats:title>\n                    <jats:p>We compared projected risk in plan\u2010level bids submitted by insurers to the actual plan\u2010level risk as subsequently reported by the Centers for Medicare and Medicaid Services (CMS). We estimated the additional A&amp;B revenue MA insurers received due to underestimates.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Data Sources and Analytical Samples<\/jats:title>\n                    <jats:p>A total of 34,604 MA plans offered by 317 insurers from 2008 to 2020 from MA Bid Data as well as MA enrollment and payment data, all from publicly available CMS sources.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Principal Findings<\/jats:title>\n                    <jats:p>From 2008 to 2020, the average ratio of actual risk to projected risk was 1.01 (95% Confidence Interval, 1.009\u20131.011) and plans received additional A&amp;B revenue of $14.6 billion due to risk underestimates. The fraction of plans with a ratio above 1.0 rose from 45% in the smallest enrollment quintile to 62% in the largest enrollment quintile. Among the 10 largest insurers, Blue Cross Blue Shield Highmark underestimated risk by the largest amount, an average of 3% from 2008 to 2020, generating $272 per member per year in additional A&amp;B revenue, followed by Centene (2.1%, $202\/member).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>From 2008 to 2020, MA plans systematically underestimated actual risk, reducing benefits for beneficiaries and generating additional A&amp;B revenue of approximately 1% of premiums. The frequency and magnitude of the underestimates increased with plan size. This additional A&amp;B revenue represents a significant fraction of reported MA profit margins, which averaged approximately 3.5% of premiums over the period. CMS should more closely scrutinize the projected risk scores in the annual bids. The Department of Justice should consider whether systematic risk underestimation is a violation of the False Claims Act.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/1475-6773.70158","type":"journal-article","created":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T00:35:16Z","timestamp":1787704516000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Medicare Advantage Plan Bid Risk Underestimates and Corresponding Insurer Revenues"],"prefix":"10.1111","volume":"61","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5885-8024","authenticated-orcid":false,"given":"David","family":"Scheinker","sequence":"first","affiliation":[{"name":"Department of Pediatrics, Stanford Medical School Stanford University  Palo Alto California USA"},{"name":"Department of Medicine, Stanford Medical School Stanford University  Palo Alto California USA"},{"name":"Clinical Excellence Research Center, Stanford Medical School Stanford University  Palo Alto California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8926-5085","authenticated-orcid":false,"given":"Kevin","family":"Schulman","sequence":"additional","affiliation":[{"name":"Department of Medicine, Stanford Medical School Stanford University  Palo Alto California USA"},{"name":"Clinical Excellence Research Center, Stanford Medical School Stanford University  Palo Alto California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7172-9956","authenticated-orcid":false,"given":"Barak","family":"Richman","sequence":"additional","affiliation":[{"name":"George Washington University Law School  Washington DC USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2794-2378","authenticated-orcid":false,"given":"Arnold","family":"Milstein","sequence":"additional","affiliation":[{"name":"Department of Medicine, Stanford Medical School Stanford University  Palo Alto California USA"},{"name":"Clinical Excellence Research Center, Stanford Medical School Stanford University  Palo Alto California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6219-0861","authenticated-orcid":false,"given":"Richard","family":"Kronick","sequence":"additional","affiliation":[{"name":"Family Medicine and Public Health The University of California  San Diego California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,8,25]]},"reference":[{"issue":"6","key":"e_1_2_9_2_1","doi-asserted-by":"crossref","first-page":"1301","DOI":"10.1016\/j.jhealeco.2013.09.004","article-title":"Competitive Bidding in Medicare Advantage: Effect of Benchmark Changes on Plan Bids","volume":"32","author":"Song Z.","year":"2013","journal-title":"Journal of Health Economics"},{"issue":"8","key":"e_1_2_9_3_1","doi-asserted-by":"crossref","DOI":"10.1093\/haschl\/qxae093","article-title":"Growing Divergence Between Medicare Advantage Plan Bids and Payments to Plans","volume":"2","author":"McCormack G.","year":"2024","journal-title":"Health Affairs Scholar"},{"key":"e_1_2_9_4_1","unstructured":"Centers for Medicare & Medicaid Services \u201cData From Medicare Advantage (MA) Bid Pricing Tools Submitted by MA Organizations \u201d2024."},{"key":"e_1_2_9_5_1","unstructured":"Centers for Medicare & Medicaid Services \u201cMedicare Advantage Plan Payment Data \u201d2025."},{"key":"e_1_2_9_6_1","unstructured":"Medicare Program \u201cMedicare Program; Changes to the Medicare Advantage and the Medicare Prescription Drug Benefit Programs for Contract Year 2012 and Other Changes \u201d2011 https:\/\/www.govinfo.gov\/content\/pkg\/FR\u20102011\u201004\u201015\/pdf\/2011\u20108274.pdf32wqq."},{"issue":"2","key":"e_1_2_9_7_1","doi-asserted-by":"crossref","first-page":"320","DOI":"10.1377\/hlthaff.2016.0768","article-title":"Projected Coding Intensity in Medicare Advantage Could Increase Medicare Spending by $200 Billion Over Ten Years","volume":"36","author":"Kronick R.","year":"2017","journal-title":"Health Affairs"},{"key":"e_1_2_9_8_1","doi-asserted-by":"crossref","unstructured":"R.KronickandF. M.Chua \u201cIndustry\u2010Wide and Sponsor\u2010Specific Estimates of Medicare Advantage Coding Intensity\u201d 2021.","DOI":"10.2139\/ssrn.3959446"},{"issue":"5","key":"e_1_2_9_9_1","doi-asserted-by":"crossref","first-page":"655","DOI":"10.7326\/ANNALS-24-01345","article-title":"Insurer\u2010Level Estimates of Revenue From Differential Coding in Medicare Advantage","volume":"178","author":"Kronick R.","year":"2025","journal-title":"Annals of Internal Medicine"},{"key":"e_1_2_9_10_1","unstructured":"Centers for Medicare & Medicaid Services \u201cMedicare Advantage Part D Contract and Enrollment Data. 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