OSGroup in Windham, NH, offers a complete suite of services for businesses and individuals that you would expect from a reputable CPA firm – audit services, tax services, and accounting support – but we are proud to say that we take our role a step further. Our goal is for you to be able to rely on us to be a part of your team of strategic business advisors, helping you through the difficult decisions you face day-to-day and week-to-week in managing and growing your business.
We feel that the success of our long-term client relationships is due to our responsiveness to clients’ needs, our experience, and our creativity. For decades, we’ve had the privilege of advising companies of all sizes in a variety of industries which has provided us with the background and breadth of knowledge to provide you sound advice and guidance for the challenges you may face running your business. Whether it’s a formal consulting assignment for developing a new business plan or advising you on a transaction to buy your largest competitor, or even just a phone call to run an idea past us, we are there for you.
Our Philosophy is simple; Provide services of value and innovative solutions to all clients – Always!
Every client survey indicates that quality and timely service are the cornerstones of a CPA firm’s success. In addition, clients want an empathetic and understanding advisor. Our goal is to meet our clients’ definitions and perceptions of quality service. We expect our clients to have high expectations of us and we continually strive to meet or exceed those expectations. Our commitment to client service and community and our forward thinking are what we believe sets us apart from other CPA firms.
We view our relationship with our clients as that of an advocate and advisor, as well as independent accountants. Our organization was founded on the premise that businesses need experienced advisors. We retain the experienced staff we believe is necessary to provide the quality advice and service our clients are looking for. Our firm constantly stays current on all matters of accounting software solutions, bookkeeping, accounting, auditing, and taxation in a very rapidly changing environment so you can be sure that you are receiving the best advice possible.
A Dedicated CPA Team
David joined the firm in 2011. He is a licensed CPA in Massachusetts and enjoys proactively assisting clients in strengthening their strategic, accounting, and compliance positions while minimizing tax since 1994.
David has direct experience in tax preparation, assurance, and business advisory with various local industries including manufacturing, construction, retail, health care, import/export, and professional services among many others.
Prior to joining OSGroup, David was a principal with a North Shore Massachusetts CPA firm. He graduated from the University of New Hampshire in Durham with a B.S. in Business Administration. He is affiliated with the AICPA and Massachusetts Society of CPAs and other local business and community-based organizations.
David lives in Atkinson, New Hampshire with his wife and three children.
After receiving the BBA from Abilene Christian University (Abilene, TX) in 1982, Joel also passed the CPA exam that same year.
As an active Partner at OSGroup, Joel’s professional interests are many and varied. They include leadership, income and estate tax planning, business management and decision-making, strategic planning, building wealth, marketing, and technology planning.
Joel’s professional affiliations include board positions with several organizations: Alexander Eastman Foundation, NH Estate Planning Council, NH Society of CPAs, Derry (NH) Economic Development Council, Chester College of NE, and the Derry 21st Century Learning Community Corporation.
Joel spends his personal time with his wife and two children in addition to volunteering his time to local non-profit activities. He also enjoys photography, gardening, and US travel.
April joined the firm in 2017 with 10 years of experience in public and private accounting. She is experienced in business and individual tax preparation, as well as audit, review and compilation engagements.
She earned her Bachelor of Science degree in Accounting and Business Administration from Northern Vermont University and is licensed in Vermont and New Hampshire as a certified public accountant.
April lives in Hampstead NH with her husband and 4 children. She is an active member in the Hampstead Mothers’ Club non-profit organization. In her free time she enjoys reading, baking and spending time outdoors with her husband and children.
Crystal joined the firm in 2014 with 11+ years of experience as a controller for a small manufacturing company and has experience in all aspects of accounting.
She has a Bachelor of Science degree in Accounting from Southern New Hampshire University and is licensed in New Hampshire as a certified public accountant. Crystal is also a Quickbooks Pro Advisor.
She lives in Londonderry, NH, and in her free time she enjoys the ocean, amusement parks and spending time with her husband and children.
Sharon P. Moge
Sharon has over thirty years of experience in finance, tax and auditing. She has worked in the public accounting sector and has held senior finance and tax positions in both private and publicly traded companies.
Sharon has extensive experience in financial reporting including business acquisitions and subsidiary consolidation, SEC reporting, stock option plan administration, federal and multi-state income and sales & use tax reporting, as well as financial and retirement plan auditing.
Sharon graduated in 1998 from Rivier College receiving her Bachelor Degree in Accounting and is an associate member of the New Hampshire Society of Certified Public Accountants.
Landon served active duty in the US Army from 2001 to 2005. He was deployed in Operation Iraqi Freedom from 2003 to 2004. In 2005, he joined OSGroup as a tax accountant.
Landon passed the special enrollment examination in August 2011 and was enrolled to practice before the Internal Revenue Service on November 3, 2011, earning the designation Enrolled Agent (EA). Landon is the Chief Technology Officer for OSGroup as well as our Charitable Gift Annuity Specialist.
Landon currently resides in Exeter, NH, where he enjoys cycling and home brewing.
Rachel joined the firm in 2019. Rachel is a Quickbooks Pro Advisor and an aspiring certified public accountant. She is proficient in charitable gift annuities and financial accounting. She is currently a third- year student at Southern New Hampshire University majoring in Accounting and will be receiving her bachelor’s degree next year.
In her free time, she likes to spend time with her family and friends. She also loves traveling, watching sports, and going to concerts.
Katherine A. Hamilton
Kathy has been with the firm for over 10 years and serves as an integral part of the administrative team.
She is married with one daughter and two dogs. Her personal time is spent enjoying her family and home, exercising, and dog training.
Cathy joined the firm in 2017 and serves as an administrative assistant.
Cathy is married and has two sons. In her free time she enjoys spending time with her family and friends, cooking, gardening, boating and skiing.
N. Charles Santamaria
Prior to joining the firm in 2013, Charlie was a shareholder with a local CPA firm. He has more than forty years of extensive experience in the areas of accounting and auditing, financial management and reporting, individual and corporate taxation, and internal controls.
Charlie graduated from Bentley College with Highest Honors and has been a licensed CPA since 1972. He is a member of the American Institute of CPA’s and the New Hampshire Society of CPA’s.
During his personal time, he enjoys hiking, fishing, cross country skiing, and snowshoeing.
Supporting Our Community
As a locally-owned and operated business, we love our neighborhoods and towns and work to make them better. We invest our time and talents to serve various community groups and you can find us donating our time with the following groups:
- American Institute of Certified Public Accountants (AICPA)
- New Hampshire Society of Certified Public Accountants (NHSCPA)
- Massachusetts Society of Certified Public Accountants (MSCPA)
- Private Companies Practice Section of the AICPA (PCPS)
- New England Peer Review, Inc.
- Upstream Academy Network of CPA Firms
- Greater Salem Chamber of Commerce
- Greater Derry Chamber of Commerce
- Best Software Select Reseller and Consultants