About us


Dr. Stefan Walzer

Dr. Stefan Walzer works in market access, pricing, health economics and reimbursement since 2004. He is the CEO and founder of MArS Market Access & Pricing Strategy GmbH and mAxInsights BV and is teaching market access & negotiations since 2012. He is also the core inventor of Market Access 4.0:

• mAxInsights, the fast & easy AI-based reimbursement planning platform
• DO-BO, the new revolutionizing way of creating reimbursement dossiers with the first and only dossier writing AI-bot
• Q-BO, the first AI-based objection handling platform
• Wafle: Negotiate with confidence – train with Wafle’s virtual reality genius in an immersive environment and with an AI based counterpart

Additionally, he also teaches at the Master course of Consumer Health Care at the Charité in Berlin (Germany) and is a tutor in market access and health technology assessment at the State University of Baden-Wuerttemberg (Germany).

He also hosts the one and only Market Access Podcast MAP.
Dr. Walzer received a Master of Science in Economics from the University of Tuebingen (Germany), a PhD in Health Economics from the University of Zurich (Switzerland) and a Diploma in Clinical Trials from the London School of Hygiene and Tropical Medicine (UK). He is co-author of more than 40 peer-reviewed scientific articles, more than 500 scientific abstracts and is editor of various scientific books.

Chief of Staff

Lutz Vollmer

Mr. Lutz Vollmer is a health economic expert with a special focus on health geography and the German market access system. He was working in Research and Administration at the Universities of Tuebingen and Kiel (Germany) for over 12 years while he was also executing primary market research projects as a free lancer. Since 2014 he supports the MArS Team as a Health Economist with a focus on payer research, health geographic solutions and the analysis of German market access decisions. In the last years he was running various interview projects in the AMNOG environment, developed successful reimbursement pathways and executed systematic literature reviews in the field of pharmaceuticals for AMNOG submissions. Furthermore he has experience in the development of reimbursement submissions for medical devices and drugs.

Mr. Vollmer is a member of the working group for “E-Health” and “Innovation in hospitals” at the German Health Economic Association (DGGÖ).

Lutz Vollmer studied geography at the Universities of Tuebingen and Stuttgart (Germany) and at the Portland State University (Oregon, USA). He holds a Master of Science in Geography and an HTA-certificate from the Free University of Berlin (Germany). Mr. Vollmer is author of several articles including research presentations and papers in geography and health economics. Also at the University of Applied Sciences of Rottenburg / Neckar (Germany), Mr. Vollmer teaches fundamentals and deeper aspects of human geography in study programs of regional management.

Projekt Manager mAxInsights

Alisa Billstein

Alisa Billstein is a health economist with a Bachelor degree from Ravensburg-Weingarten University of Applied Sciences.
Her background is as a physiotherapist with experience in a physiotherapeutic practice as well as in clinical environment.
She specialized in the fields of neurology, orthopaedics and sports physiotherapy. She has also worked as an honorary sports physiotherapist for a GFL1 American football team.

Junior Health Economist

Dunia Krüger

Dunia Krueger is a physiotherapist by training and has over 25 years work experience especially in the areas of orthopedics, surgery and oncology. She is experienced in medical accounting and coding as well as in direct discussions and negotiations with health insurances. Dunia Krueger is also knowledgable in cost and medical data searching and its interpretation.

Senior Market Access Manager

Sebastian Krenberger

Sebastian Krenberger is a health economist and holds a Master in Public Health from the University of Applied Sciences Fulda (Germany). Additionally, Sebastian is a (intensive care) nurse with more than 7 years of experience in various departments and responsibilities at the clinic Fulda and the university hospital of Kiel.

Sebastian has a broad medical understanding in various disease areas and the process within hospitals. Furthermore he is a public health and market process expert for Germany.

Senior Market Access Manager

Bernd Bleuel

Bernd is a health economist and has more than 28 years of experience in the German health system. He combines practical experience in dealing with and managing patients with experience in billing in the inpatient and outpatient sector. In addition, Bernd has been in charge of contract negotiations for various BKKs over the last few years, e.g. within the framework of pharmaceutical discount agreements.
Bernd is a registered nurse, has a degree in nursing management (Darmstadt University of Applied Sciences) and holds a Master of Health Administration from the University of Bielfeld. 

Clinical Science Advisor

Dr. Andreas Voss

Dr. Voss is an internist with a focus on oncology. After 10 years of clinical practice at the University Hospital in Hamburg Eppendorf, he started his career in the pharmaceutical industry, where he was responsible for global clinical development, regulatory affairs and marketing of numerous drugs. He has worked in large companies (AstraZeneca, Roche) as well as in small and medium sized companies and gained broad experience in various roles. Dr. Voss has led several clinical development programs and has been responsible for over 150 regulatory processes, including ‘orphan drugs’ and pediatric indications. Prior to becoming an independent consultant, Dr. Voss served as Managing Director at Caris Life Sciences International, where he was responsible for the development and sales of assays for personalized medicine.

Andreas Voss is the Clinical Science Advisor at MArS. 

Health Economist

Jochen Feuerstein

Mr. Feuerstein is a Health Economic Writer at MArS. Before joining MArS he gained much experience in a variety of industries including pharmaceuticals and the Fulda Health Authority. Here he was responsible for summarising complex data and to prepare it for decision-making.

Furthermore, Mr. Feuerstein wrote various scientific papers on relevant topics. He completed his Master’s degree in Public Health at the University of Applied Sciences Fulda. The focus of his studies was on occupational health management and environment, and health.

Previously, Mr. Feuerstein completed an apprenticeship as a media designer and worked independently in communications for 15 years. His strength lies in coordinating complex, interrelated processes and connecting theory and practice.

Management Assistant

Sabrina Walzer

Ms. Walzer has more than 11 years of experience in practice management of outpatient medical practices and affiliated doctors in Germany in the field of dermatology, onco-dermatology, surgery and orthopedics.


Market Access Manager

Ilse-Barbara Oelze

Ilse-Barbara Oelze is a Market Access Manager at MArS. Previously she worked at Certara Evidence & Access in Germany where she gained substantial experience in pricing and market access consulting projects. She is also a specialist for pricing and cost evaluations for the German market.

Ilse-Barbara holds a Master in Health Economics and Pharmacoeconomics (MPHE) from Pompeu Fabra University, School of Management in Barcelona. She also holds a degree in business administration (equivalent to a MS in business administration) from the University of Applied Sciences, Neu-Ulm, with a focus in Hospital Management. Additionally, she has studied law at the University in Freiburg.

Prior Ilse- Barbara gained experience in health care politics and health care management as well as in developing DRGs and costing of ambulant treatments. She has held several positions within hospitals and SHIs (statutory health insurances) in Germany. Through her professional experiences and graduate education, she has gained strong analytical skills and a global strategic vision.

Market Access Intern

Jonas Jost

Jonas Jost is a Market Access Intern at MArS. Jonas has experience in the health and social environment in Germany since 2009. He worked already for many years in the care environment including leadership and organizational roles. Furthermore he is currently just studying health economics at the University of Applied Sciences Weingarten-Ravensburg (Germany).

Market Access Trainee

Yannick Walzer

Yannick Walzer is a Market Access Trainee at MArS. Previously he gained experience in a private insurance company before he studies health economics at the University of Applied Sciences Weingarten-Ravensburg (Germany). Yannick primarily focuses on epidemiologic analyses including medical writing of AMNOG modules 3 and payer researches across the D-A-CH region.

Working Student

Amelie Schmid