One county, many local governments
Washtenaw County has about 370,214 people (Census Bureau 2025 estimate). Cities and townships here are separate local governments, and the difference matters once a mold job turns into a rebuild. The city of Ypsilanti and Ypsilanti Township, for example, run separate rental programs. Two communities also cross county lines: Milan is split between Washtenaw and Monroe counties, and Whitmore Lake spans Washtenaw and Livingston counties.
Requests from smaller places such as Manchester, Lodi and Webster are welcome too.
Permits, in short. Mold cleanup itself usually isn't permitted work, but rebuilding (drywall, insulation, framing, waterproofing) often is. Ann Arbor's building division and each township issue their own permits. Your contractor should confirm with your city or township and pull any permit.
Rules that are the same everywhere
Michigan doesn't license mold remediation companies, and the state health department doesn't certify mold remediators or testers. Repair and rebuild work of $600 or more, such as replacing drywall or insulation, generally needs a Residential Builder or Maintenance & Alteration license from LARA (MCL 339.2401–2404). Ask for the license number and verify it with LARA.
The June 2021 storm led to federal disaster declaration DR-4607, which covered Washtenaw County. Wherever you live, EPA advises drying water-damaged areas within 24 to 48 hours. Ann Arbor's own prevention advice, a footing drain disconnection, a backwater or check valve on the sewer lead, and downspouts and grading that move water away from the house, applies well beyond the city limits.
Start with basement mold, mold after leaks and basement flooding or mold in rentals and student housing, or check the cost guide.