About Us

We are OnCall.

Preferred provider of outsourced sales solutions
to the healthcare industry.

Whether your product has just received FDA clearance and is ready to take the world by storm or is a mature brand with remaining profit potential, we stand ready to support your evolving needs and solve your toughest sales challenges in all phases of the product lifecycle.

Through decades of experience, we’ve demonstrated success promoting prescription, consumer healthcare, medical device and diagnostic products to healthcare professionals across multiple therapeutic categories.

Today, we offer the established processes and unmatched infrastructure to rapidly build, scale and support sales teams of all sizes.

Our culture: becoming invaluable to our clients.

Some things never change. Like the human values that guide our work at OnCall. We’re committed to doing business with transparency and integrity. Excellence is in our DNA, and has been since our founding in 1996.

We are passionate about our work, our clients, the science, the industry and the patients. We challenge and support each other – and our clients – to do things that cause change and have a lasting positive impact. In order to provide our clients with the greatest value, we pride ourselves in never being satisfied with the status quo. Instead, we operate as entrepreneurs, taking ownership of your challenges, accommodating your needs and proactively solving problems.

Our leadership: the heart of OnCall.

The OnCall Senior Management Team are experts in their field, and represent a combined 90+ years of healthcare sales and marketing leadership.

Walter Dewees, Managing Director

Walt has built his career with a laser focus on the healthcare industry, successfully leading global, national and regional engagements for OnCall clients spanning pharmaceuticals, the medical device industry, consumer healthcare, diagnostics, veterinary medicine, and dental products and equipment.

Over the past 25 years, he has led pre-launch and launch planning for numerous high-profile sales force deployments across the country and around the world. Our clients draw upon Walt’s extensive experience in building and managing high-performing sales teams, as well as his deep knowledge of the global healthcare space. He is passionate about forging collaborative relationships with them, and delivering measurable business results.

John Sage, Director of Sales Operations and Information Technology

John is a man of many accomplishments. In addition to being responsible for all IT client services and internal IT operations for the past 16 years, he also manages Sales Operations functions for OnCall. And does it all extremely well.

He considers his success a product of being able to simplify IT complexity for OnCall clients and sales teams, so they in turn can focus on strategic direction and selling. John finds most satisfying the process of building and implementing novel solutions, or providing unique insights. Ultimately, he loves the idea that his skills are being used to improve the quality of life of patients.


To promote use of essential clinical preventive services, Maryellen partnered with the New York City Department of Health and Mental Hygiene to deploy the very first city-wide Public Health Detailing Program, a primary care provider outreach initiative modeled on pharmaceutical detailing.  Since then and the for the last 14 years, Maryellen has supported major municipalities nationwide to design and implement similar healthcare professional outreach programs.  Maryellen is passionate about the effectiveness of Public health Detailing to deliver key prevention messages and improve clinical prevention services. 

Jennifer Davis, Senior Client Finance Manager

OnCall counts on Jen for oversight of financial reporting and forecasting, and she counts on her years of experience at a Big Four CPA firm to carry out her duties with precision and professionalism.

But Jen’s responsibilities don’t end there. As a member of OnCall’s corporate financial leadership team, she also supports senior management by supplying contract pricing and other financial needs, ultimately reporting to corporate holding company WPP. Supporting executive management while growing her own career is how Jen defines success – and how OnCall defines financial stability.

Jim Tenhunfeld, Director of Talent Acquisition

For more than 20 years, Jim has specialized in sourcing high-performing sales and sales management talent for leading healthcare companies in the U.S. and abroad. He leads OnCall’s 15-member talent acquisition team and plays an instrumental role in our sales team deployments.

Jim is passionate about finding that perfect sales representative or sales manager in the perfect location, and he consistently demonstrates an uncanny ability to source high-performing talent – even when faced with the most aggressive timelines.

Michelle Parker, Client Finance Director

Michelle’s four-year OnCall career has been focused on supporting clients in the preparation, examination, and analyzing of accounting records, financial statements and other reports to assess accuracy, completeness and conformance to reporting and procedural standards.

As an integral part of both field and inside sales deployments, she has developed, maintained and analyzed budgets, preparing periodic reports that compare budgeted project costs to actual costs. Michelle enjoys being part of the OnCall team – and we enjoy her many contributions.