The path from enforcing the tax code to advocating for taxpayers isn’t a common one, but for MD Sullivan, it was inevitable. With a career that spans high-risk government service, private sector innovation, and national thought leadership, Sullivan has become a name synonymous with tax resolution in South Florida.
Sullivan’s early professional years were spent deeply entrenched in the Internal Revenue Service. As a Revenue Officer working in the IRS’s elite Narcotics Trafficking Program, he wasn’t confined to office cubicles or spreadsheets. He was on the streets, collaborating with the DEA, FBI, and local law enforcement in South Florida at the height of the “Cocaine Cowboys” era. His job was to seize and liquidate the lavish assets of drug lords: cigarette boats, funeral homes, gold bars, luxury cars, and multimillion-dollar estates.
With over 300 seizures under his belt, Sullivan’s cases read like a movie script. He’s been targeted by cartels, had his car defaced on his front lawn, and survived an attempt to be burned alive during a seizure operation gone wrong.
Despite the dangers, Sullivan thrived in this high-intensity environment. He was recognized internally for his work, receiving multiple certificates of appreciation. Though, as he ironically points out, they didn’t get handed bonuses, especially with their life on the line.
The turning point came in 1982. After ten years of dedicated service, Sullivan made the heart-wrenching decision to walk away. His wife (then a bank manager) was shot at point-blank range during a robbery. That day, July 23, 1982, became the end of his federal career and the beginning of something radically different.
With insider knowledge of IRS operations and a deep understanding of the nuances of tax collection policies, Sullivan shifted gears. He began representing taxpayers instead of pursuing them, founding what would become a highly respected tax resolution practice.
Over the years, he partnered with industry professionals, building a clientele that included business owners, celebrities, and high-net-worth individuals. His expertise in the Offer in Compromise (OIC) program, often referred to as the IRS’s debt settlement option, made him one of the leading voices in tax resolution across the United States.
Through MD Sullivan LLC, he has resolved thousands of IRS cases, saved clients millions in tax liabilities, and developed a reputation as the “go-to guy” for those in deep tax trouble.
But Sullivan’s contributions didn’t stop at individual casework. Recognizing a broader need in the industry, he became a certified IRS instructor, training new agents at the Atlanta Service Center. Later, in the private sector, he earned certifications from the Florida Department of Professional Regulation to teach attorneys and CPAs.
His most impactful contribution to the tax professional community is The Tax Mob, a private Facebook group of over 5,300 members that includes CPAs, enrolled agents, tax attorneys, and former IRS officials from across the country. It’s more than a forum; it’s a knowledge-sharing hub, mentorship space, and networking engine for professionals at every level.
Sullivan also organizes an annual Tax Mob Convention, drawing hundreds of practitioners to cities like Nashville, Las Vegas, Denver, and this year, Puerto Rico. These gatherings blend professional development with camaraderie and have become a cornerstone of the tax resolution world.
Sullivan’s expertise hasn’t gone unnoticed by the media. He has been featured on FOX Business, ABC’s The Briefing Room, NewsNation, Newsmax, and other outlets, offering commentary on tax policy, enforcement trends, and IRS operations.
His YouTube channel, ‘Help from a Former IRS Agent,’ boasts over 1.7 million views and more than 2,600 subscribers. Through video explainers, case studies, and live Q&As, he continues to educate and empower both taxpayers and professionals.
Today, MD Sullivan continues to represent clients, teach the next generation of tax professionals, and build bridges between IRS procedures and public understanding. Whether he’s filing an OIC, training a young CPA, or suing Jimmy Hoffa’s stepson for a lost coat, Sullivan remains guided by grit, integrity, and a relentless drive to serve.
What started as a ten-year stint inside one of the most powerful federal agencies has become a lifelong mission to bring clarity, fairness, and resolution to those facing the IRS. And in the world of tax problems, having a seasoned fighter like MD Sullivan on your side can make all the difference.