Encouraging Medicare Advantage Enrollees to Switch to Higher Quality Plans: Assessing the Effectiveness of a "Nudge" Letter.

There are considerable quality differences across private Medicare Advantage insurance plans, so it is important that beneficiaries make informed choices. During open enrollment for the 2013 coverage year, the Centers for Medicare & Medicaid Services sent letters to beneficiaries enrolled in low-quality Medicare Advantage plans (i.e., plans rated less than 3 stars for at least 3 consecutive years by Medicare) explaining the stars and encouraging them to reexamine their choices. To understand the effectiveness of these low-cost, behavioral "nudge" letters, we used a beneficiary-level national retrospective cohort and performed multivariate regression analysis of plan selection during the 2013 open enrollment period among those enrolled in plans rated less than 3 stars. Our analysis controls for beneficiary demographic characteristics, health and health care spending risks, the availability of alternative higher rated plan options in their local market, and historical disenrollment rates from the plans. We compared the behaviors of those beneficiaries who received the nudge letters with those who enrolled in similar poorly rated plans but did not receive such letters. We found that beneficiaries who received the nudge letter were almost twice as likely (28.0% [95% confidence interval = 27.7%, 28.2%] vs. 15.3% [95% confidence interval = 15.1%, 15.5%]) to switch to a higher rated plan compared with those who did not receive the letter. White beneficiaries, healthier beneficiaries, and those residing in areas with more high-performing plan choices were more likely to switch plans in response to the nudge. Our findings highlight both the importance and efficacy of providing timely and actionable information to beneficiaries about quality in the insurance marketplace to facilitate informed and value-based coverage decisions.

One-Year Outcomes of Diabetes Self-Management Training Among Medicare Beneficiaries Newly Diagnosed With Diabetes.

BACKGROUND: Diabetes is highly prevalent among Medicare beneficiaries, resulting in costly health care utilization. Strategies to improve health outcomes, such as disease self-management, could help reduce the increasing burden of diabetes. OBJECTIVES: Short-term benefits of diabetes self-management training (DSMT) are established; however, longer-term impacts among Medicare beneficiaries are unknown. RESEARCH DESIGN: Claims-based observational study with 1-year follow-up beginning 6 months after diabetes diagnosis. SUBJECTS: Twenty percent random sample of Medicare beneficiaries newly diagnosed with diabetes during 2009-2011 who used DSMT (N=14,680), matched to a nonuser comparison group. MEASURES: We compared health service utilization and costs between DSMT users and nonusers. Health service utilization included any utilization of the hospital or emergency department (ED) and any hospitalizations due to diabetes-related ambulatory care sensitive conditions as well as the number of hospitalizations and ED visits within the follow-up year. Costs included all Medicare Parts A and B expenditures. RESULTS: Multivariate regression results found that DSMT users had 14% reduced odds of any hospitalization, lower numbers of hospitalizations and ED visits (approximately 3 fewer per 100 for each), and approximately $830 lower Medicare expenditures (95% CI, -$1198, -$470) compared with nonusers. Odds of any hospitalization due to diabetes-related ambulatory care sensitive conditions and any ED visit were lower for DSMT users compared with nonusers, but the reductions were not statistically significant. CONCLUSIONS: Findings demonstrate benefits from DSMT use, including lower health service utilization and costs. The low cost of DSMT relative to the reduction in Medicare expenditures highlights an opportunity to reduce the burden of diabetes on both individuals and the health care system.

Patterns of care for clinically distinct segments of high cost Medicare beneficiaries.

BACKGROUND: Efforts to improve the efficiency of care for the Medicare population commonly target high cost beneficiaries. We describe and evaluate a novel management approach, population segmentation, for identifying and managing high cost beneficiaries. METHODS: A retrospective cross-sectional analysis of 6,919,439 Medicare fee-for-service beneficiaries in 2012. We defined and characterized eight distinct clinical population segments, and assessed heterogeneity in managing practitioners. RESULTS: The eight segments comprised 9.8% of the population and 47.6% of annual Medicare payments. The eight segments included 61% and 69% of the population in the top decile and top 5% of annual Medicare payments. The positive-predictive values within each segment for meeting thresholds of Medicare payments ranged from 72% to 100%, 30% to 83%, and 14% to 56% for the upper quartile, upper decile, and upper 5% of Medicare payments respectively. Sensitivity and positive-predictive values were substantially improved over predictive algorithms based on historical utilization patterns and comorbidities. The mean [95% confidence interval] number of unique practitioners and practices delivering E&M services ranged from 1.82 [1.79-1.84] to 6.94 [6.91-6.98] and 1.48 [1.46-1.50] to 4.98 [4.95-5.00] respectively. The percentage of cognitive services delivered by primary care practitioners ranged from 23.8% to 67.9% across segments, with significant variability among specialty types. CONCLUSIONS: Most high cost Medicare beneficiaries can be identified based on a single clinical reason and are managed by different practitioners. IMPLICATIONS: Population segmentation holds potential to improve efficiency in the Medicare population by identifying opportunities to improve care for specific populations and managing clinicians, and forecasting and evaluating the impact of specific interventions.

An Assessment of Performance Between Medicare Advantage and Stand-Alone Prescription Drug Plans on Two Quality Assurance Measures.

The purpose of our study was to compare performance between Medicare Advantage and stand-alone prescription drug plans on the two quality assurance measures of drug-disease interaction and drug-drug interaction for elderly heart failure beneficiaries. Performance on the drug-disease interaction measure appeared more problematic for stand-alone plan enrollees compared with Medicare Advantage plan enrollees. No statistical difference existed between the plans regarding drug-drug interactions. It appears there may be considerable room for more sophisticated use of disease profiling in the processing of drug claims. The provision of richer clinical data is an essential step to improving performance on the drug-disease interaction measure.

An Assessment of Three Post-Discharge Drug-Based Quality Assurance Events for Elderly Medicare Beneficiaries Enrolled in a Stand-Alone Part D Plan.

This article examines the distribution of drug-based quality assurance events (QAEs) post-discharge across five-day increments and identifies characteristics associated with post-discharge QAEs. Data were obtained through a cross-sectional study of Medicare beneficiaries age 65 and over enrolled in stand-alone Part D plans during calendar year 2010. Our findings suggest an even more compressed timeframe than previously identified in the literature for addressing medication issues among elderly beneficiaries. Specifically, medication reconciliation is needed within two to three days of discharge instead of within 14 days as the literature suggests. To decrease inadvertent readmissions, an immediate in-community medication reconciliation following hospital discharge is needed.

Wide variation in payments for Medicare beneficiary oncology services suggests room for practice-level improvement.

In recent years many policy makers have recommended alternative payment models in medical oncology in order to reduce costs and improve patient outcomes. Yet information on how oncology practices differ in their use of key service categories is limited. We measured annual payments for key service categories delivered to fee-for-service Medicare beneficiaries receiving care from 1,534 medical oncology practices in 2011-12. In 2012, differences in payments per beneficiary at the seventy-fifth-percentile practice compared to the twenty-fifth-percentile practice were $3,866 for chemotherapy (including administration and supportive care drugs), $1,872 for acute medical hospitalizations, and $439 for advanced imaging. Supportive care drugs, bevacizumab, and positron-emission tomography accounted for the greatest percentage of variation. Average practice payments for service categories were highly correlated across years but not correlated with each other, which suggests that service categories may be affected by different physician practice characteristics. These differences, even when clinical guidelines exist, demonstrate the potential for quality improvement that could be accelerated through alternative payment models.

Use of Medicare's Diabetes Self-Management Training Benefit.

Medicare began reimbursing for outpatient diabetes self-management training (DSMT) in 2000; however, little is known about program utilization. Individuals diagnosed with diabetes in 2010 were identified from a 20% random selection of the Medicare fee-for-service population (N = 110,064). Medicare administrative and claims files were used to determine DSMT utilization. Multivariate logistic regression analyses evaluated the association of demographic, health status, and provider availability factors with DSMT utilization. Approximately 5% of Medicare beneficiaries with newly diagnosed diabetes used DSMT services. The adjusted odds of any utilization were lower among men compared with women, older individuals compared with younger, non-Whites compared with Whites, people dually eligible for Medicare and Medicaid compared with nondual eligibles, and patients with comorbidities compared with individuals without those conditions. Additionally, the adjusted odds of utilizing DSMT increased as the availability of providers who offered DSMT services increased and varied by Census region. Utilization of DSMT among Medicare beneficiaries with newly diagnosed diabetes is low. There appear to be marked disparities in access to DSMT by demographic and health status factors and availability of DSMT providers. In light of the increasing prevalence of diabetes, future research should identify barriers to DSMT access, describe DSMT providers, and explore the impact of DSMT services. With preventive services being increasingly covered by insurers, the low utilization of DSMT, a preventive service benefit that has existed for almost 15 years, highlights the challenges that may be encountered to achieve widespread dissemination and uptake of the new services.

Cumulative expenditures under the DI, SSI, Medicare, and Medicaid programs for a cohort of disabled working-age adults.

OBJECTIVE: To estimate cumulative DI, SSI, Medicare, and Medicaid expenditures from initial disability benefit award to death or age 65. DATA SOURCES: Administrative records for a cohort of new CY2000 DI and SSI awardees aged 18-64. STUDY DESIGN: Actual expenditures were obtained for 2000-2006/7. Subsequent expenditures were simulated using a regression-adjusted Markov process to assign individuals to annual disability benefit coverage states. Program expenditures were simulated conditional on assigned benefit coverage status. Estimates reflect present value of expenditures at initial award in 2000 and are expressed in constant 2012 dollars. Expenditure estimates were also updated to reflect benefit levels and characteristics of new awardees in 2012. DATA COLLECTION: We matched records for a 10 percent nationally representative sample. PRINCIPAL FINDINGS: Overall average cumulative expenditures are $292,401 through death or age 65, with 51.4 percent for cash benefits and 48.6 percent for health care. Expenditures are about twice the average for individuals first awarded benefits at age 18-30. Overall average expenditures increased by 10 percent when updated for a simulated 2012 cohort. CONCLUSIONS: Data on cumulative expenditures, especially combined across programs, are useful for evaluating the long-term payoff of investments designed to modify entry to and exit from the disability rolls.

Understanding factors associated with loss of medicaid coverage among dual eligibles can help identify vulnerable enrollees.

For people who receive both Medicare and Medicaid benefits (dual-eligible beneficiaries), the loss of Medicaid coverage may lead to problems with care coordination, higher out-of-pocket expenses, or reduced access to services. Using administrative data, we followed 292,242 full-benefit and 91,020 partial-benefit dual eligibles from January 2009 through December 2011. Among those with full Medicaid benefits, 15.6 percent lost Medicaid coverage at least once, with more frequent losses among younger beneficiaries. Many of these losses lasted only one to three months and were followed by reinstatement. Loss of Medicaid coverage was more common (23.2 percent) among enrollees with partial Medicaid benefits. Medicare Current Beneficiary Survey data indicate that most dual eligibles who lost Medicaid coverage had no other source of supplemental insurance. Medicaid coverage is relatively stable among dual eligibles. However, some lose Medicaid for several months or more, putting them at risk for poor outcomes and potentially complicating their care, especially when it needs to be integrated under the two programs.

Longitudinal patterns of Medicaid and Medicare coverage among disability cash benefit awardees.

This article explores the role of the Social Security Disability Insurance (DI) and Supplemental Security Income (SSI) cash benefit programs in providing access to public health insurance coverage among working-aged people with disabilities, using a sample of administrative records spanning 84 months. We find that complex longitudinal interactions between DI and SSI eligibility determine access to and timing of Medicare and Medicaid coverage. SSI plays an important role in providing a pathway to Medicaid coverage for many low-income individuals during the 29-month combined DI and Medicare waiting periods, when Medicare coverage is not available. After Medicare eligibility kicks in, public health insurance coverage is virtually complete among awardees with some DI involvement. Medicaid coverage continues at or above 90 percent after 2 years for SSI-only awardees. Many people who exit SSI retain their Medicaid coverage, but the gap in coverage between stayers and those who leave SSI increases over time.

Applying the 2003 Beers update to elderly Medicare enrollees in the Part D program.

BACKGROUND: Inappropriate prescribing of certain medications known as Beers drugs may be harmful to the elderly, because the potential risk for an adverse outcome outweighs the potential benefit. OBJECTIVES: (1) To assess Beers drug use in dual enrollees compared to non-duals; (2) to explore the association between dual enrollment status and Beers use, controlling for the effects of age, gender, race/ethnicity, census region, and health status; (3) to assess which medication therapeutic category had the highest Beers use. DESIGN: Cross sectional retrospective review of 2007 Centers for Medicare & Medicaid Service Part D data. Potentially inappropriate medication use was assessed, independent of diagnosis, using the 2003 update by Fick et al. FINDINGS: The likelihood of Beers drug use among duals approximates that of non-duals (OR 1.023, 95% CI 1.020-1.026). Characteristics associated with the receipt of a Beers medication include Hispanic origin, younger age, female gender, poor health status, and residence outside of the U.S.' Northeast region. Genitourinary products had the highest Beers use within medication therapeutic categories among both dual and non-dual enrollees (21.1% and 19.9%, respectively). CONCLUSIONS: Part D data can be successfully used to monitor Beers drug use. With adjustments for several important and easily measured demographic, health, and prescription drug use covariates, Beers drug use appears to be as common among non-dual enrollees as it is among dual enrollees in the Part D program. New Part D drug utilization policies that apply to all beneficiaries may need to be enacted to reduce Beers drug use.

Impact of continued biased disenrollment from the Medicare Advantage Program to fee-for-service.

BACKGROUND: Medicare managed care enrollees who disenroll to fee-for-service (FFS) historically have worse health and higher costs than continuing enrollees and beneficiaries remaining in FFS. OBJECTIVE: To examine disenrollment patterns by analyzing Medicare payments following disenrollment from Medicare Advantage (MA) to FFS in 2007. Recent growth in the MA program, introduction of limits on timing of enrollment/disenrollment, and initiation of prescription drug benefits may have substantially changed the dynamics of disenrollment. STUDY DESIGN: The study was based on MA enrollees who disenrolled to FFS in 2007 (N=248,779) and a sample of "FFS stayers" residing in the same counties as the disenrollees (N=551,616). Actual Medicare Part A and Part B payments (excluding hospice payments) in the six months following disenrollment were compared with predicted payments based on claims experience of local FFS stayers, adjusted for CMS-Hierarchical Condition Category (CMS-HCC) risk scores. RESULTS: Disenrollees incurred $1,021 per month in Medicare payments, compared with $798 in predicted payments (ratio of actual/predicted=1.28, p < 0.001). Differences between actual and predicted payments were smaller for disenrollees of Preferred Provider Organizations and Private Fee-for-Service plans than of Health Maintenance Organizations. Analysis of 10 individual MA plans revealed variation in the degree of selective disenrollment. CONCLUSIONS: Despite substantial changes in policies and market characteristics of the Medicare managed care program, disenrollment to FFS continues to occur disproportionately among high-cost beneficiaries, raising concerns about care experiences among sicker enrollees and increased costs to Medicare.

Endocrine therapy use among elderly hormone receptor-positive breast cancer patients enrolled in Medicare Part D.

BACKGROUND: Clinical guidelines recommend that women with hormone-receptor positive breast cancer receive endocrine therapy (selective estrogen receptor modulators [SERMs] or aromatase inhibitors [AIs]) for five years following diagnosis. OBJECTIVE: To examine utilization and adherence to therapy for SERMs and AIs in Medicare Part D prescription drug plans. DATA: Linked Surveillance, Epidemiology, and End Results (SEER)-Medicare data. STUDY DESIGN: We identified 15,542 elderly women diagnosed with hormone-receptor positive breast cancer in years 2003-2005 (the latest SEER data at the time of the study) and enrolled in a Part D plan in 2006 or 2007 (the initial years of Part D). This permitted us to compare utilization and adherence to therapy at various points within the recommended five-year timeframe for endocrine therapy. SERM and AI use was measured from claim records. Non-adherence to therapy was defined as a medication possession ratio of less than 80 percent. PRINCIPAL FINDINGS: Between May 2006 and December 2007, 22 percent of beneficiaries received SERM, 52 percent AI, and 26 percent received neither. The percent receiving any endocrine therapy decreased with time from diagnosis. Among SERM and AI users, 20-30 percent were non-adherent to therapy; out-of-pocket costs were higher for AI than SERM and were strongly associated with non-adherence. For AI users without a low income subsidy, adherence to therapy deteriorated after reaching the Part D coverage gap. CONCLUSIONS: Many elderly breast cancer patients were not receiving therapy for the recommended five years following diagnosis. Choosing a Part D plan that minimizes out-of-pocket costs is critical to ensuring beneficiary access to essential medications.

Noncompliance in the use of cardiovascular medications in the Medicare Part D population.

OBJECTIVES: (1) to assess non-compliance among Medicare Part D recipients for the cardiovascular medication classes; (2) to identify the probability of noncompliance for each medication class when controlling for the potential risk factors of age, gender, race/ethnic origin, census region, disease burden, dual eligibility enrollment status, Part D plan status, relative out-of-pocket (OOP) non-class costs, and relative OOP daily class costs. DESIGN: Cross sectional retrospective review of 2007 Centers for Medicare & Medicaid Services (CMS) Part D data. All drugs within a drug class were used to conduct the assessment. FINDINGS: Non-compliance was found to be lower than previously reported. Patients who are male, age 65 to 74, Black, or residing in the South are associated with higher noncompliance for cardiovascular medications among the therapeutic classes we studied. Dual eligibility enrollment is typically associated with improved compliance; enrollment in a Medicare Advantage Prescription Drug (MAPD) plan may or may not improve compliance dependent on the therapeutic class under study. Increased disease burden is associated with lower compliance. OOP non-class costs had an opposing effect on compliance as compared to OOP daily costs; higher OOP non-class costs were associated with better compliance. CONCLUSION: Identifying patient characteristics that may contribute positively or negatively to medication compliance is an essential step to improved therapy. As a strategy to improve compliance, the proper selection of therapy that fits a particular patient is paramount.

Long-term trends in Medicare payments in the last year of life.

OBJECTIVE: To update research on Medicare payments in the last year of life. DATA SOURCES: Continuous Medicare History Sample, containing annual summaries of claims data on a 5 percent sample from 1978 to 2006. STUDY DESIGN: Analyses were based on elderly beneficiaries in fee for service. For each year, Medicare payments were assigned either to decedents (persons in their last year) or to survivors (all others). RESULTS: The share of Medicare payments going to persons in their last year of life declined slightly from 28.3 percent in 1978 to 25.1 percent in 2006. After adjustment for age, sex, and death rates, there was no significant trend. CONCLUSIONS: Despite changes in the delivery of medical care over the last generation, the share of Medicare expenditures going to beneficiaries in their last year has not changed substantially.

Adverse selection in the Medicare prescription drug program.

The Medicare Part D drug benefit created choices for beneficiaries among many prescription drug plans with varying levels of coverage. As a result, Medicare enrollees with high prescription drug costs have strong incentives to enroll in Part D, especially in plans with more comprehensive coverage. To measure this potential problem of "adverse selection," which could threaten plans' finances, we compared baseline characteristics among groups of beneficiaries with various drug coverage arrangements in 2006. We found some significant differences. For example, enrollees in stand-alone prescription drug plans, especially in plans offering benefits in the coverage gap, or "doughnut hole," had higher baseline drug costs and worse health than enrollees in Medicare Advantage prescription drug plans. Although risk-adjusted payments and other measures have been put in place to account for selection, these patterns could adversely affect future Medicare costs and should be watched carefully.

Administrative and claims records as sources of health care cost data.

BACKGROUND: Many economic studies of disease require cost data at the person level to identify diagnosed cases and to capture the type and timing of specific services. One source of cost data is claims and other administrative records associated with health insurance programs and health care providers. OBJECTIVE: To describe and compare strengths and limitations of various administrative and claims databases. DATA AND METHODS: Data sources included claims and enrollment records from Medicare, Medicaid, and private insurers; Veterans' Health Administration records; state hospital discharge datasets; Healthcare Cost and Utilization Project hospital databases; managed care plan data systems; and provider cost reports. Claims provide information on payments, whereas cost reports yield resource costs incurred to produce services. Administrative data may be significantly augmented by linkage to disease registries and surveys. RESULTS: Administrative data are often available for large, enrolled populations, have detailed information on individual service use, and can be aggregated by service type, episode, and patient. Service use and costs can often be tracked longitudinally. Because they are not collected for research purposes, administrative data can be difficult to access and use. Limitations include generalizability, complexity, coverage and benefit restrictions, and lack of coverage continuity. Linked datasets permit identification of incident cases of disease, and analyses of health care costs by stage at diagnosis, phase of care, comorbidity status, income, and insurance status. CONCLUSIONS: Administrative data are an essential source of information for studies of the financial burden of disease. Cost estimates can vary substantially by specific measures (payments, charges, cost to charge ratios) and across data sources.

Trends in out-of-pocket healthcare costs among older community-dwelling Medicare beneficiaries.

OBJECTIVE: To describe trends in out-of-pocket healthcare costs, including insurance premiums, for older Medicare beneficiaries living in the community. STUDY DESIGN: Medicare Current Beneficiary Survey data were analyzed for community-dwelling beneficiaries 65 years or older between 1992 and 2004. METHODS: The primary focus of the analysis was out-of-pocket healthcare costs and out-of-pocket costs as a percentage of income. Descriptive statistics are presented for 1992, 1996, 2000, and 2004. RESULTS: Inflation-adjusted median out-of-pocket costs were stable between 1992 and 2000 and then rose by 21.7% between 2000 and 2004. Median costs as a percentage of income declined between 1992 and 1996 but increased from 12.6% in 2000 to 15.5% in 2004. Between 1992 and 2004, out-of-pocket costs increased fastest at the upper percentiles of the distribution. High out-of-pocket costs tended to persist from year to year, exacerbating the financial burden for some beneficiaries. CONCLUSIONS: Following a period of declining burden between 1992 and 1996, out-of-pocket healthcare costs rose significantly between 2000 and 2004, increasing the financial burden for many older Medicare beneficiaries. These data provide a baseline for evaluating Medicare reform proposals that affect beneficiary spending.

Comparison of cancer diagnosis and treatment in Medicare fee-for-service and managed care plans.

OBJECTIVE: To compare the Medicare managed care (MC) and fee-for-service (FFS) sectors on stage at diagnosis and treatment patterns for prostate, female breast, and colorectal cancers, and to examine patterns across MC plans. DATA: Surveillance, Epidemiology, and End Results-Medicare linked data. METHODS: Among cases diagnosed at ages 65-79 between 1998 and 2002, we selected all MC enrollees (n = 42,467) and beneficiaries in FFS (n = 82,998) who resided in the same counties. MC and FFS samples were compared using logistic regression, adjusting for demographic, geographic, and clinical covariates. RESULTS: The percentage of late stage cases was similar in MC and FFS for prostate and colorectal cancers; there were slightly fewer late stage breast cancer cases in MC after adjustment (7.3% vs. 8.5%, P < 0.001). Within MC, radical prostatectomy was performed less frequently for clinically localized prostate cancer (18.3% vs. 22.4%, P < 0.0001), and 12 or more lymph nodes were examined less often for resected colon cancer cases (40.9% vs. 43.0%, P < 0.05). Treatment patterns for early stage breast cancer were similar in MC and FFS. Analyses of treatment patterns at the individual plan level revealed significant variation among plans, as well as within the FFS sector, for all 3 types of cancer. CONCLUSIONS: On average, there are few significant differences in cancer diagnosis and treatment between MC and FFS. Such comparisons, however, mask the wide variability among MC plans, as well as FFS providers. Observed variation in patterns of care may be related to patient selection, but can potentially lead to outcome differences. These findings support the need for quality measures to evaluate plan practices and performance.

Disenrollment from Medicare managed care among beneficiaries with and without a cancer diagnosis.

BACKGROUND: Medicare managed care may offer enrollees lower out-of-pocket costs and provide benefits that are not available in the traditional fee-for-service Medicare program. However, managed care plans may also restrict provider choice in an effort to control costs. We compared rates of voluntary disenrollment from Medicare managed care to traditional fee-for-service Medicare among Medicare managed care enrollees with and without a cancer diagnosis. METHODS: We identified Medicare managed care enrollees aged 65 years or older who were diagnosed with a first primary breast (n = 28 331), colorectal (n = 26 494), prostate (n = 29 046), or lung (n = 31 243) cancer from January 1, 1995, through December 31, 2002, in Surveillance, Epidemiology, and End Results (SEER) cancer registry records linked with Medicare enrollment files. Cancer patients were pair-matched to cancer-free enrollees by age, sex, race, and geographic location. We estimated rates of voluntary disenrollment to fee-for-service Medicare in the 2 years after each cancer patient's diagnosis, adjusted for plan characteristics and Medicare managed care penetration, by use of Cox proportional hazards regression. RESULTS: In the 2 years after diagnosis, cancer patients were less likely to disenroll from Medicare managed care than their matched cancer-free peers (for breast cancer, adjusted hazard ratio [HR] for disenrollment = 0.78, 95% confidence interval [CI] = 0.74 to 0.82; for colorectal cancer, HR = 0.84, 95% CI = 0.80 to 0.88; for prostate cancer, HR = 0.86, 95% CI = 0.82 to 0.90; and for lung cancer, HR = 0.81, 95% CI = 0.76 to 0.86). Results were consistent across strata of age, sex, race, SEER registry, and cancer stage. CONCLUSION: A new cancer diagnosis between 1995 and 2002 did not precipitate voluntary disenrollment from Medicare managed care to traditional fee-for-service Medicare.