Stephan P. McMahon & Companyis a progressive and innovative firm committed to strategic knowledge development and its transfer to our clients to foster and optimize their success. What does success mean to you?

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  • It has been wonderful to develop a real business partnership between our two companies. I truly appreciated everything your firm has done for my business, and I will and have wholeheartedly recommend anyone who asks me to SPM&CO.

    Gail O’Rourke, President – White Wood Kitchens

  • Thank you for your great support! We appreciate your special attention to our “urgent” needs prior to and after leaving for Sierra Leone.

    Allen Morell – New Covenant Foundation, Inc.

  • It is great to know that we can reach out to you when needed. Thank you! We so appreciated how quickly you respond to help us and how committed you always seem to our family.

    John & Pam Domos – Domos Carpentry

  • Thank you for your support! Your donation helped make our event a huge success!

    Kelvin & Amy Ing – Cape Cod Challenger Club

  • Thank you so much for taking the time to meet with us yesterday. Figuring out our withholdings together was very reassuring. Paul and I are so happy you are our accountant. You are very smart, capable, and personable too! We are in good hands!

    Leslie Chizek

  • Amazing accountant! Extremely knowledgeable and professional. I recommend Stephan to anyone looking for a great accountant.

    Natalia Wiener – Gibson Sotheby’s International Realty

  • In December I had my first zoom meeting with Stephan. It was obvious from the start that my business was more than “another number."  He analyzed our situation and I learned more about my company during that 30 minute meeting, than I had in 10 years with previous accountants.  Stephan and his crew have been a valuable resource.  I feel 100% confident knowing that SPM&Co is in my corner!

    John Day – J Day Off Road

  • I admire your growth, stability and excellent reputation on the Cape. I'm very excited to be part of your team.

    Michael D. Pierce, Esq.

  • Stephan and his staff are outstanding! I can strongly attest to their professionalism and knowledge. They are very proactive and make sure their clients are well aware of any changes and are quick with great advice! SPM&Co has been instrumental in helping me grow my business. Working with SPM&Co will be one of the best things you can do for the health and longevity of your personal and business financials.

    Brian Greer – Greer Real Estate

  • Thank you! The impact of your gift goes a long way in helping feed hungry children. With your help, Cape Kid Meals is changing the face of childhood hunger on Cape Cod.

    Tammy Leone – Cape Kid Meals

  • I have use various CPA's throughout my career and Stephan is the best. He is proactive and not reactive. He strategizes solutions in advance which is quite refreshing.

    Steven Pizzuti – Pizzuti Law

  • Best in class! Hands down.

    Jon Clark – Nauset Management

  • As CEO of a startup company, I need professional help dealing with a wide range of finance and accounting issues. SPM solves my problems quickly and provides insightful advice for dealing with business challenges. I recommended them to another company I am invested in and they are now clients of SPM. Good decision!

    Rusty Warren – Armada Marine Robotics

Our forward focused Process
is our proven way in which we accomplish great results with our clients

We get that it can be “lonely at the top” but when partnering with SPM&Co, we ensure that you will never feel alone on your entrepreneurial journey. We will work closely with you to help you discover your goals, needs & opportunities for your business. Once we set the course of action, we will align our energies into a particular program that will guarantee a winning experience.


: 75 mins

In-Person/Video Session

  • About us / About you
  • Business information gathering
  • Exploration of goals & needs
  • Introduce programs & processes

Schedule Alignment


SPM&Co Team starts ideation of the plan:

  • Discovery meeting review
  • Review of client provided books/records
  • Opportunities, needs & goals assessment
  • Tailored Program services recommendation

: 45 mins

In-Person/Video Session

  • Client meets their SPM&Co Team
  • Review proposed plan
  • Set the projections & course of action
  • Partnership & expectation alignment

Affirm Program


SPM&Co Team begins onboarding process:

  • Welcoming & Administrative tasks completed
  • Kicks off the program & starts execution of the plan

Client Experience

Our commitment to our team and clients is “The Experience is the #1 Thing”. We ensure this outcome through consistent and continuous client engagement with ongoing follow-up during and after service delivery.

Contemporary compliance


Contemporary compliance

We go beyond the basic tax planning and preparation for tax returns to help our clients put strategies into play that extract the most value for their business and support the growth and preservation of their overall opportunities and personal wealth.

Benchmarking to build greater success

By analyzing the market and garnering competitive research, we will take clients above planning and compliance and ascend them next level by identifying and applying the notable best practices to their business and tax strategies, not by imitating but by innovating! Ultimately, business owners’ will be equipped with KPIs and management scorecards which will enable and lead to continued and growing success.

Benchmarking to build greater success


Success in the approach


Success in the approach

We help give aspiring business owners the confidence they need when starting a business venture. We aid in defining and refining your plan, determining capital needs, reviewing entity selection and business structure, preparing budgets, and navigating you through all the important aspects of starting and then growing your business.

Defining business worth

With help our clients answer questions involving compliance, litigation, and transaction consulting so they can have a clear picture of what their business and business assets are worth – giving them peace of mind as their business evolves or ascends to the next chapter.

Defining business worth

Business Valuation

Serving Cape Cod & the South Shore

SPM&Co “On Cape”

Cape Cod Accountant Office in West Yarmouth MA

196 Old Town House Rd,
West Yarmouth, MA 02673
(508) 775-0518

SPM&Co “Off Cape”

Plymouth, MA accountant office

57 Obery St #1,
Plymouth, MA 02360
(508) 830-0800

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