Who we are
The Hiatt Accounting Group is a family-owned and operated accounting and tax advisory firm built on more than 80 years of combined experience. What began with Mark Hiatt’s dedication to personalized business guidance has grown into a multi-generational practice committed to helping individuals, families, and small businesses thrive.
Mark Hiatt, Accountant brings over 40 years of experience advising business owners with strategic planning and tax solutions.
Adam Hiatt, Enrolled Agent, represents the next generation of the firm, focused on modernizing our practice with technology, efficiency, and fresh approaches to client service.
Together, we blend deep expertise with a personal touch. Our mission is simple: to provide clarity, confidence, and peace of mind so our clients can focus on what matters most.
our vision
We understand the realities of running a small business. Most owners operate leanly and wear many hats — but few are financial experts. Time spent wrestling with bookkeeping, payroll, tax filings, or compliance is time taken away from what truly drives success: developing products and services, serving customers, and building a pipeline for growth. Hiring full-time staff for accounting or tax is often unrealistic or cost-prohibitive, which is where we come in.
Our vision is to be the financial partner that complements the strengths of small business owners. By taking the burden of accounting, bookkeeping, and tax planning off their shoulders, we give them back the time and confidence to focus on growth — without compromise.
For individuals and families, we bring the same commitment. Life is filled with transitions — buying a home, raising children, planning for college, preparing for retirement, or navigating inheritances. Each stage brings financial complexity, and without guidance, opportunities are often missed. Our role is to simplify the process, uncover savings, and create strategies that reduce tax liability and protect your future.
Whether you’re a small business looking to scale, or a family planning for tomorrow, our vision is clear: to deliver financial clarity, reduce stress, and support your goals with expertise you can trust.
FAQs
What areas do YOU serve?
We proudly provide tax and accounting services to individuals, families, and businesses throughout Castle Rock, Castle Pines, Highlands Ranch, Parker, Littleton, Lone Tree, Centennial, Englewood, Greenwood Village, the Denver Tech Center, Elizabeth, Larkspur, Monument, and Colorado Springs. As a South Denver–based firm, we understand the needs of our local communities. We also work with clients virtually across Colorado and nationwide, offering the same secure, personalized service wherever you are.
Do i need to live in Colorado to work with you?
Not at all. While our office is based in Castle Rock in the South Denver metro area, many of our clients work with us virtually. We use secure, easy-to-use tools to handle document sharing, video consultations, and tax filing, so distance is never an issue.
Do you offer in person meetings?
Yes. We welcome in-person appointments for local clients in Castle Rock and surrounding areas, and we also offer convenient virtual meetings for those who prefer to connect online. Whether you’re in Castle Rock, Highlands Ranch, Parker, or Colorado Springs, or across the country, we make it simple to meet in the way that works best for you.
Can you help me if I own property or run a business in multiple states?
Yes. Many of our Castle Rock, Colorado Springs, and South Denver-area clients have property or business operations in other states. Multi-state taxation happens to be one of our specialties. Whether you own rental properties across different states, run a business that operates in multiple jurisdictions, or have income sourced from more than one state, we can ensure you stay compliant while minimizing unnecessary tax burdens. Our team has experience handling:
Multi-state individual income tax filings
Business entity filings and compliance across state lines
Sales and use tax registrations and reporting
Residency and domicile considerations
Strategies to avoid double taxation
We coordinate everything so your filings work together smoothly, saving you time, stress, and money.
Contact us
Interested in working together? Fill out some info and we will be in touch shortly. We can’t wait to hear from you!