Experts

Actuary

Eddie Armentrout has worked at ARC since 2009, applying actuarial analysis to support health programs and policy evaluation. He has extensive experience with long-term care policy analysis, Medicare and Medicaid payment systems, and the implementation and analysis of Medicare payment demonstrations.

Mr. Armentrout’s current and past roles include acting as ARC’s lead in the actuarial pricing review of Medicare Advantage bids, leading the development of regional benchmarks for a Medicare Innovations Model, and consulting with state agencies to evaluate the potential impacts of public long-term care benefit proposals. He has extensive experience working with survey data and developing quantitative models to estimate policy impacts.

Mr. Armentrout holds a B.A. in Economics and Applied Statistics from the University of Virginia. He is an Associate of the Society of Actuaries (ASA) and a Member of the American Academy of Actuaries (MAAA).

Actuary

Ryan Brake has worked at ARC since 2007, working on a wide array of actuarial, employee benefits, and health policy projects, for the Federal Government and non-governmental clients. He has significant experience with both Medicare Fee for Service and Medicare Advantage (including Prescription Drug) payment and delivery systems. He has performed modeling for payment reform proposals, performed statistical analysis, and performed detailed actuarial review tasks. Over his career at ARC, Mr. Brake has assisted the Department of Labor in producing annual statistical bulletins related to both private pension and group health plans. In addition to broad knowledge of the landscape of social insurance in the United States, Mr. Brake is also an experienced programmer, proficient in SAS, SQL, R, and VBA.

Most recently, Mr. Brake has been ARC’s lead in supporting CMS’s Value-Based Insurance Design (VBID) model with actuarial, analytic, and technical support. This work has included direct involvement in the development and support of the model since its inception in 2017.

Mr. Brake holds a B.A. in Mathematics from the University of Virginia. He is an Associate of the Society of Actuaries (ASA) and a Member of the American Academy of Actuaries (MAAA).

Senior Actuary

Tim Bulat is a Senior Actuary with ARC, with 20 years of experience in health care financing in the United States and international markets. At ARC, he specializes in the evolution of public/private managed care programs, policy evaluation, and long-term care program development.

Tim joined ARC in 2022, following a successful career with Cigna. At Cigna, Tim held financial, actuarial, and analytics roles across multiple health insurance segments. Most recently, he was Managing Director of Cigna’s Data & Analytics department supporting government businesses, which included Medicare, Medicaid, and Marketplace products. In this role, he led the analytics which drove Cigna Government’s COVID-19 response, and he oversaw the modernization of analytics and business engagement processes in several areas including risk adjustment, contracting, and utilization & case management program evaluation. At Cigna, he also served in several senior actuarial and financial roles, including Chief Actuary of the Supplemental Health division, Actuarial Senior Director of Commercial Markets and Products, and Finance Officer for the International Private Medical Insurance product line. In this latter role, he was part of a small team which successfully started a new rapidly growing product line offering individual private medical insurance in several countries across Europe and Asia.

Tim is a Fellow of the Society of Actuaries and Member of the American Academy of Actuaries. He is currently pursuing a Master of Public Health from the University of Pennsylvania and holds a Bachelor of Science in Computer Science & Engineering from the University of Connecticut.

Senior Actuary

Cathi Callahan is a Senior Actuary with a background in mathematics and emphasis in economics. She joined ARC in 1986 and has over thirty-five years of experience in analyzing proposed and implemented health policy developments, including the implementation and refinement of computer models to analyze national health expenditure patterns and to model coverage and spending under public and private programs, as well as providing actuarial support, rate and risk adjustment review, and financial modeling. She has served as a project director as well as a senior technical analyst/actuary for numerous clients.

Ms. Callahan’s work has included Medicare and Medicaid analysis for a variety of clients, modeling using custom C programming, and database work including tools such as Excel. These include the calculation of actuarial values and their impact on actual health insurance costs, coverage, and medical spending. She has provided technical support to state Medicaid agencies in strategic thinking and the design of financial simulations for Medicaid alternative payment models (APMs) and value-based purchasing (VBP) strategies and has worked with states and CMS to identify and analyze Medicaid data to support the strategic selection, design, and testing of VBP approaches and related activities.

Ms. Callahan is an Associate of the Society of Actuaries, a Member of the American Academy of Actuaries, and holds a B.S. in Mathematics from The College of William and Mary in Virginia.

Actuarial Student/Program Analyst

Luke Coughlan joined ARC in 2019, working on a variety of actuarial, employee benefits, and health policy contracts. In his time at ARC, he has gained considerable experience with Medicare Fee for Service and Medicare Advantage (including Prescription Drug) payment and delivery systems, performed detailed actuarial review tasks, statistical analyses, and modeling, and participated in the publication of various formal documents communicating this work. Mr. Coughlan has participated in the Department of Labor’s production of annual statistical bulletins related to private pension and group health plans. He also has experience with programming tasks involving the SAS, SQL, R, and VBA programming languages.

Mr. Coughlan began his career as a secondary mathematics and theory of knowledge teacher in 2012, where he developed a broad knowledge of fundamental mathematical concepts as well as experience in communicating them efficiently and effectively in a learning environment. He led various student and faculty teams and provided technical support to the school community throughout his teaching career. Mr. Coughlan uses his teaching and learning acumen from his prior career on a daily basis at ARC.

Mr. Coughlan holds a B.A in Mathematics and English from Boston University and has passed Exams P and FM in pursuit of becoming an Associate of the Society of Actuaries.

Senior Actuary

Brandi Dries is a healthcare actuary with over 20 years of experience, specializing in government-related healthcare consulting with actuarial components and health policy implications.

Brandi joined ARC in 2024 where her specific areas of actuarial expertise include Medicare and Medicaid payment and delivery systems, Medicare Advantage bid pricing and evaluation, and Original Medicare Model design, implementation, and evaluation. Prior to joining ARC, Brandi worked as a Senior Director for The Cigna Group where she led a team that supported the Medicare Advantage Part C actuarial bid pricing and development. Prior to Cigna, Brandi worked as a Senior Associate for Mercer Government Human Services Consulting, where she was a project manager and pricing actuary for complex state Medicaid managed care rate setting projects and a lead actuary for CMS Medicare Advantage bid desk reviews and audits.

Brandi is a Fellow of the Society of Actuaries and a Member of the American Academy of Actuaries and holds a Bachelor of Science in Statistics from Iowa State University.

Research Analyst

Logan Johnson is an Analyst for ARC and has worked on a variety of economic and actuarial projects performing health policy research, data analytics, and economic modeling. Most of her work at ARC is focused on assisting in the development of demonstrations under the Innovation center. These projects require a variety of analyses, which can vary from background research to regression analysis to data interpretation which helps inform the model team’s decision making.

In addition, Logan works with the Medicare Physician Fee Schedule (PFS) rate setting group, providing analysis and modeling support, as well as programming assistance.

Logan received her B.A. in Economics from the College of William & Mary in 2015 and her M.A. in Economic Policy Analysis from the University of Maryland, Baltimore County in 201.

Senior Actuary

Kerry Ketler is a Senior Actuary at ARC, having joined the company in 2000. She has over 20 years of experience in health care modeling and analysis, research, pricing, policy analysis, and social insurance modeling and over 12 years of project leadership experience. Her current and past projects include implementation and analysis of Medicare demonstrations and models, analysis of Medicare and Medicaid utilization and cost among select cohorts, review and audit of Medicare Advantage bids, review of capitation payment rates and risk adjustment modeling for the TRICARE military healthcare system, and public social insurance modeling for transition economies outside of the United States. Her experience working in these areas has provided a deep understanding of Medicare fee-for-service model implementation and payment, as well as risk adjustment strategies.

Ms. Ketler is responsible for managing resources and workflows to meet project deliverables, analyzing results, providing actuarial and other expertise, and communicating with clients regularly to maintain project goals.

Ms. Ketler holds a BS in Mathematics from the University of Maryland, Baltimore County. She is a Fellow of the Society of Actuaries (FSA) and a member of the American Academy of Actuaries (MAAA).

Senior Research Analyst

Ramona Krauss is a health economist and joined ARC in January 2016. Dr. Krauss has over 14 years of experience in economic and health policy research and modeling. Most of her work at ARC is focused on identifying costs and savings for specialty episodes of care for different models that aim to decrease the cost of care while maintaining or improving the quality of care. She provides analytical support to CMS and other clients during the pre-implementation and implementation of various demonstrations, assisting with desired beneficiary population identification and creating episodes of care, risk adjustments, expenditures, and quality indicators for the populations of interest. Dr. Krauss is very familiar with using, maintaining, and interpreting cross sectional and longitudinal national and state-specific Medicare data as well as nationally representative survey data.

Currently, Dr. Krauss is the co-director and the lead analyst for the Enhancing Oncology Model (EOM). Her team produces data-driven analyses that inform the policy choices around most of the model components, such as attribution methodology, prediction model risk adjustments and functional form choices, and quality measures selection and benchmarking.

Dr. Krauss received her B.A. in Economics and Psychology, her M.A. in Economics, and her Ph.D. in Economics from the University of Illinois at Chicago. Prior to moving to the U.S., she was a Pediatric Nurse at the Children’s Emergency Hospital Grigore Alexandrescu, Bucharest, Romania for over 7 years (Spring 1994–Fall 2001).

Senior Research Analyst

Katie Merrell joined ARC as a Senior Research Analyst in 2016. She has over thirty years of experience as a health policy researcher, using data to inform policy development and refinement. Recognized as a national expert on Medicare physician payment policy, she wrote the suite of programs that CMS currently uses to calculate practice expense and malpractice expense relative values. For over a decade, she has led the team that provides real-time support to the CMS physician rate setting group so is involved in virtually every aspect of physician rate setting, including policy development and simulation, data development and management, and final relative value calculation. She has led or supported analyses of a variety of payment models as part of ARC’s ongoing support of data development and analysis for CMMI. Before coming to ARC, she served as principal investigator or co-investigator on federal, state, and foundation-funded projects on a range of topics including the cost of the medical home model, evaluations and analyses of maternal and child health programs and policy innovations, and the design of the then-novel Medicare hospice benefit. Many of these projects resulted in articles published in peer-reviewed health policy and medical journals.

While at the University of Chicago, she helped create the Health Studies Department within the Biological Sciences Division, organized the health economics workshop, and taught master’s level courses on data analysis and the health care system, among other responsibilities.

Senior Programmer/Actuarial Analyst

Alicia Nussbaum is a Senior Programmer and Actuarial Analyst for ARC. She has worked on a variety of actuarial projects since joining the team in 2013. She works primarily on model design and development for the Centers for Medicare and Medicaid Services (CMS) using her extensive experience with Medicare and Medicaid claims to develop utilization and expenditure estimates. She is skilled in several programming languages and utilizes knowledge of CMS databases in her ongoing work at ARC.

Ms. Nussbaum holds a B.S. in Computer Science from the University of Maryland, Baltimore County (UMBC).

Actuarial Analyst

Crystal Quirino joined ARC in April 2022 as an Analyst. She has professional experience in financial reporting, workforce projections and analytics, and all-staff training. She spends most of her day programming Medicare and Medicaid based datasets and tabulating results in Excel or PowerBI. She specializes in data visualization techniques, presentations, and cross-organizational planning.

Ms. Quirino holds a Master of Science in Data Analytics Engineering from George Mason University and a Bachelor of Science in Actuarial Science with minors in both Statistics and Business from Florida State University.

Actuary

Michael Sandler is an Actuary for ARC. Over his more than 15-year career, Mr. Sandler has developed and updated several long-term actuarial projection models and worked on several Medicare demonstration projects. His areas of expertise include Medicare Advantage, health care reform design and modeling, long term actuarial modeling and program evaluation.

Mr. Sandler joined ARC in 2006. He has led ARC’s Actuarial Savings Modeling and Analysis for DEMME as well as leading a team providing actuarial analysis and support for proposed legislative mandates in the state of Minnesota. Mr. Sandler was involved in the design and implementation, as well as monitoring and evaluation, for the Financial Alignment Initiative and he has lent his data and modeling expertise to several CMS demonstrations over the years including BIPA, MCMP, FQHC, FCHIP, P3C, PACEPlus, VBID 2.0, Advanced Care Planning and the MOM Model. Additionally, he has reviewed the reasonableness of bids submitted by MA and PDP plan sponsors for more than a decade.

Mr. Sandler holds a B.S. in Mathematics and B.A. in Economics from the University of Maryland and is an Associate of the Society of Actuaries and a Member of the American Academy of Actuaries.

Senior Research Analyst

Elizabeth Schaefer is a Senior Research Analyst at ARC. She has over 25 years of experience as a health services researcher working on topics in Medicare and Medicaid advanced payment models, military health care, veterans’ health care, and employer-sponsored health insurance coverage. Ms. Schaefer joined ARC in 2015, and prior to that, she spent 10 years on the Health Research and Policy team at the Center for Naval Analyses (CNA) and 7 years at the Center for Studying Health System Change (HSC). Her project roles have primarily been analyst, task lead, and project director, and her skills and expertise include statistical and other quantitative analysis, report writing, data presentation, and survey research methods and instrument design.

Ms. Schaefer holds an M.A. in Economics from Princeton University and a B.A. in Economics from Bryn Mawr College.

Senior Research Analyst

Rebecca Socarras is a Senior Research Analyst at ARC and has worked on a variety of economic and actuarial projects since joining in 2008. The majority of her efforts have focused on health services research, policy analysis and economic modeling.

Her work includes developing cost and population estimates for a variety of health policy proposals relevant to several major payers and programs aimed at slowing the rate of cost growth and limiting health spending. She also has a wide range of experience providing analytic support for demonstrations and models at the Centers for Medicare and Medicaid Services (CMS). She is skilled in the use of statistical programming software including Stata and SAS and has experience working with Medicare claims data, hospital cost data, and survey data.

Dr. Socarras holds a Ph.D. in Public Policy, with a concentration in Economics, from the University of Maryland, Baltimore County (UMBC). She also has an M.A. in Economic Policy Analysis and a B.S. in Financial Economics from UMBC.

Actuary

Alex Styduhar is an Actuary at ARC, and joined the company in 2013. He has worked on a variety of actuarial and public policy projects, developing extensive experience with government-funded healthcare payment and delivery systems such as Medicare Fee for Service, Medicare Advantage (MA), and Medicaid. He also has experience with long-term care insurance modeling and statistical analysis of ERISA-covered employee benefits. He is highly skilled in using a variety of programming languages—SAS, SQL, and Visual Basic for Applications (VBA)—to manipulate, tabulate, summarize, and interpret data for research and review purposes.

Most recently, Mr. Styduhar has provided real-time support to the Medicare Physician Fee Schedule (PFS) rate setting group, including payment rate calculation, data development and management, and policy evaluation and modeling. He also leads a team that regularly updates the Geographic Practice Cost Indices (GPCIs) and the Malpractice Risk Index, two key inputs to the annual PFS rate setting process. He has also worked on a variety of actuarial and rate review projects for CMS, including reviews of actuarial bids and medical loss ratio reports submitted by MA and Prescription Drug Plan (PDP) organizations, review of MA Value Based Insurance Design (VBID) applications, rate review for Medicare-Medicaid Plans participating in the Financial Alignment Initiative demonstration, and review of states’ risk adjustment provisions for their Medicaid expansion populations.

Prior to working at ARC, Mr. Styduhar worked for the CMS Office of the Actuary and pursued a career in secondary math education. He also volunteers as a youth soccer coach and mentor and enjoys hiking, biking, live music, and watching Baltimore sports teams…when they are winning 🙂

Mr. Styduhar holds a BS in Mathematical Economics from the University of Richmond and an M.A.T. in Secondary Mathematics Education from American University. He is an Associate of the Society of Actuaries (ASA) and a member of the American Academy of Actuaries (MAAA).

Actuary

Rodelle Williams has worked for Actuarial Research Corporation for over 20 years, having joined ARC in 1998. Her areas of expertise include demographic modeling with many of the large databases used in health services research, and actuarial analysis of plans. Ms. Williams works extensively with Medicaid and Medicare data including risk corridors, rate reviews, and minimum loss ratios as well as with a variety of Demonstrations including the Medicare Advantage Value Based Insurance Design and the Medicare-Medicaid Financial Alignment Initiative. Her work also involves in-depth analysis of Employer Sponsored Insurance including funding, plan types, and actuarial values. In-house and external actuarial value calculators are frequent tools as well as custom programs to perform imputations to augment public use datasets.

Ms. Williams holds a B.A. in Physics and Economics from the University of Virginia, and is an Associate of the Society of Actuaries, and Member of the American Academy of Actuaries.

Senior Programmer

Erika Yoshino is a Senior Programmer and Actuarial Analyst for ARC. She has worked on many Medicare demonstrations for the Centers of Medicare and Medicaid Services (CMS) over the years. She has extensive experience working with large health care datasets and actuarial modeling, including developing expenditures estimates, algorithms for beneficiary attribution, and diagnosis-based risk adjustment. Before joining ARC, Erika was a statistical analyst for Colorado’s Medicaid program.

Erika holds a BA in Economics from the University of Colorado Boulder, and an MSc in Actuarial Science from Bayes Business School, City University of London.