For fiscal year 2015, VA estimated it received $59.2 billion in appropriations, including collections, to fund health care services for veterans, manage and administer VA’s health care system, and operate and maintain the VA health care system’s capital infrastructure. VA estimated that in fiscal year 2015 it provided health care services— including inpatient services, outpatient services, and prescription drugs— to 6.7 million eligible patients. For calendar year 2015, the Medicare Trustees estimated that CMS paid MA plans about $155 billion to provide coverage for 16.4 million Medicare beneficiaries. Beneficiaries of MA can enroll in one of several different plan types, including health maintenance organizations (HMO), private fee-for-service (PFFS) plans, preferred provider organizations (PPO), and regional PPOs. Medicare pays MA plans a capitated PMPM amount. This amount is based in part on a plan’s bid, which is its projection of the revenue it requires to provide a beneficiary with services that are covered under Medicare FFS, and a benchmark, which CMS generally calculates from average per capita Medicare FFS spending in the plan’s service area and other factors. If a plan’s bid is higher than the benchmark, Medicare pays the plan the amount of the benchmark, and the plan must charge beneficiaries a premium to collect the amount by which the bid exceeds the benchmark. If the plan’s bid is lower than the benchmark, Medicare pays the plan the amount of the bid and makes an additional payment to the plan called a rebate. Plans may use this rebate to fund benefits not covered under Medicare FFS. CMS uses risk scores to adjust PMPM payments to MA plans to account for beneficiaries’ health status and other factors, a process known as risk adjustment. For beneficiaries enrolled in MA, risk scores are generally determined on the basis of diagnosis codes submitted for each beneficiary, among other factors, and are adjusted annually to account for changes in diagnoses from the previous calendar year. In addition, risk scores for beneficiaries who experience long-term stays of more than 90 days are calculated differently to account for the differences in expected health expenditures. While risk scores are based on diagnoses from the previous year, changes to the risk score to account for long-term hospital stays of more than 90 days are reflected in the calendar year when the stay occurred. The Patient Protection and Affordable Care Act (PPACA) changed how benchmarks are calculated so that they will be more closely aligned with Medicare FFS spending. Specifically, the benchmark changes, which are to be phased in from 2012 through 2017, will result in benchmarks tied to a percentage of per capita Medicare FFS spending in each county. In general, for those counties in the highest Medicare FFS spending quartile, benchmarks will be equal to 95 percent of county per capita Medicare FFS spending, and for those counties in the lowest Medicare FFS spending quartile, benchmarks will be equal to 115 percent of per capita Medicare FFS spending. Prior to 2012, benchmarks in all counties were at least as high as per capita Medicare FFS spending, but were often much higher. For example, while counties generally had benchmarks that were derived from per capita county Medicare FFS spending, the benchmarks were generally increased annually by a minimum update equal to the national growth rate percentage in Medicare FFS spending. In cases where the growth rate used to update the benchmark was greater than the rate at which per capita Medicare FFS spending grew within a county, it would result in a benchmark that was higher than the average per capita county Medicare FFS spending rate. In addition, some urban and rural counties had benchmarks that were “floor” rates, which were set above per capita county Medicare FFS spending rates to encourage insurers to offer plans in the areas. According to a CMS study reported in the 2010 MA Advance Notice, approximately 96 percent of counties had benchmarks that were set based on a minimum update or were floor rates. Especially in counties with a relatively high proportion of veterans, average per capita Medicare FFS spending may be low if many veterans receive health care services from VA instead of Medicare providers. Because benchmarks are calculated based in part on Medicare FFS spending, MA payments may be lower in such counties and may not reflect Medicare’s expected cost of caring for nonveterans. CMS is required to estimate, on a per capita basis, the amount of additional Medicare FFS payments that would have been made in a county if Medicare-eligible veterans had not received services from VA. If needed, CMS is also required to make a corresponding MA payment adjustment. To address these requirements, CMS reported the results of its study analyzing the cost impact of removing veterans eligible to receive services from VA on 2009 Medicare FFS county rates in the 2010 MA Advance Notice. CMS reported that, on average, removing veterans from the calculation of counties’ per capita Medicare FFS spending rate had minimal impact on per capita spending and that the differences in expenditures between all Medicare beneficiaries and nonveterans were more attributable to normal, random variation than to distinctly different spending for the two populations. Based on CMS’s study results, the agency concluded that no adjustment for VA spending on Medicare- covered services was necessary to 2010 through 2016 MA payments. In 2016, CMS updated its 2009 study using more recent data and determined that an adjustment would be necessary for 2017. VA provided about $2.4 billion in Medicare-covered inpatient and outpatient services to the 833,684 MA-enrolled veterans in fiscal year 2010. In total, VA provided approximately 61,000 inpatient services and 8.2 million outpatient services to veterans enrolled in MA plans. During that same time period, CMS paid MA plans $8.3 billion to provide all Medicare-covered services to veterans enrolled in an MA plan. VA’s provision of services to MA-enrolled veterans resulted in overall payments to MA plans that were likely lower than they otherwise would have been if veterans had obtained all of their Medicare-covered services through Medicare FFS providers and MA plans. Specifically, because VA provides services to MA-enrolled veterans, the three components that determine payments to MA plans—benchmarks, bids, and risk scores— are likely lower than they otherwise would be, which results in lower overall payments to MA plans. Benchmarks—Because benchmarks are generally calculated in part from per capita county Medicare FFS spending rates, any VA spending on Medicare-covered services for veterans enrolled in Medicare FFS would be excluded from the benchmark calculation. As a result, the benchmark would be lower and, in turn, payments to MA plans would also be lower. This would be particularly true following the implementation of the PPACA revisions to the benchmark calculation—to be phased in from 2012 through 2017—as the PPACA revisions further strengthened the link between the benchmark and average per capita county Medicare FFS spending rates. Bids—MA payments also may be lower to the extent that MA plans set bids based on historical experience. MA plan bids may reflect the fact that in previous years enrolled veterans received some Medicare- covered services from VA instead of the MA plan. If so, MA plan bids would be lower and, in turn, MA payments would also be lower. Risk scores—VA’s provision of Medicare-covered services may result in lower risk scores because, like benchmarks, they are calibrated based on Medicare FFS spending for beneficiaries with specific diagnoses identified by Medicare. As a result, any VA spending on Medicare-covered services for veterans enrolled in Medicare FFS that is related to these diagnoses would be excluded when the model is calibrated. In addition, MA plans would generally not have access to diagnoses made by VA. Therefore, when VA identifies and treats a diagnosis not identified by the veteran’s MA plan, it would not be incorporated into the veteran’s risk score. Because PMPM payments to MA plans are risk-adjusted, a lower risk score would result in lower payments to MA plans. Although VA spending on Medicare-covered services likely results in lower CMS payments to MA plans, the extent to which these payments reflect the expected utilization of services by the MA population remains uncertain. Specifically, payment amounts may still be too high or could even be too low, depending on the utilization of VA services by veterans enrolled in MA plans and veterans enrolled in Medicare FFS. As noted earlier, both benchmarks and risk scores are generally calibrated based on veterans and nonveterans enrolled in Medicare FFS. However, veterans enrolled in MA plans may differ in the proportion of services they receive from VA compared to veterans enrolled in Medicare FFS, which would affect the appropriateness of payments to MA plans. For example, payments to MA plans may be too high if veterans enrolled in MA receive a greater proportion of their services from VA relative to veterans enrolled in Medicare FFS. Under this scenario, the benchmark would reflect the higher use of Medicare services by Medicare FFS beneficiaries who are receiving fewer of their services from VA than are veterans enrolled in MA. As a result, the benchmark may be too high and, in turn, payments to MA plans may be too high. This effect of a higher benchmark may be at least partially offset by a risk score that is too high. In contrast, payments to MA plans may be too low if veterans enrolled in MA receive a lesser proportion of their services from VA relative to veterans enrolled in Medicare FFS. Under this scenario, the benchmarks may be too low and may result in MA plans being underpaid, although the effect may be partially offset by risk scores that are too low. To assess whether there are service utilization differences between the MA and Medicare FFS veteran populations that result in payments to MA plans that are too high or too low, data on the services veterans receive from Medicare FFS, MA, and VA would be needed. Data on veterans’ use of services through Medicare FFS and VA health care are available from CMS and VA, respectively. However, CMS does not currently have validated data that could be used to determine veterans’ use of services through MA.