Plain-English guide
Why your mortgage payment can jump after your first year in a Michigan home
In Michigan, this often happens because of the property tax pop-up, the delayed tax increase that can follow a sale. Your early mortgage payment may be based on the seller's old tax bill. After the home sells, Taxable Value — the number Michigan uses to calculate the property tax bill — can reset. Then the tax bill can rise, and your escrow payment, the part set aside for taxes and insurance, may jump.
The short version
Michigan voters passed Proposal A in 1994. It created a cap on how fast a property's Taxable Value can rise while the same owner keeps the property. That cap is the lesser of 5% or the state's inflation multiplier.
The inflation multiplier is the yearly number Michigan uses to set that cap. Think of it as the speed limit for Taxable Value while the same owner keeps the home. For the 2026 tax year, the multiplier is 1.027, which means 2.7%. Michigan posts the official list of inflation rate multipliers.
When the property transfers to a new owner, that cap usually resets. The Taxable Value moves close to the State Equalized Value, or SEV. SEV is commonly about half of market value. That reset is the pop-up.
Why tax history can look lower than your future bill
Many real estate listings show what the current owner paid. If the seller owned the house for 15 years, their Taxable Value may be far below today's value. The buyer usually does not inherit that protected number in a normal sale.
For example, a seller may pay tax on a $110,000 Taxable Value even though the home sells for $400,000. The buyer's SEV might be around $200,000. If the millage rate is 40 mills, that difference alone changes the yearly bill by about $3,600.
When does the higher bill arrive?
The higher bill usually arrives in the calendar year after closing. If you close in June 2026, the 2026 bill normally still reflects the seller's capped value. The 2027 bill is where the reset shows up.
What this calculator estimates
The calculator uses the local millage rate, the purchase price, and the current Taxable Value if you know it. It estimates the buyer's new Taxable Value as half the purchase price, then compares seller tax with buyer tax.
Assessors do not simply set SEV to half the sale price. They use market studies and comparable sales. That is why the result is an estimate, not a guarantee.
This guide explains how the math works, but it is not legal or tax advice. For your specific situation, confirm with your local assessor or a Michigan tax professional.
Sources and review
Where this information comes from
Uncapping rules come from Michigan Treasury guidance, State Tax Commission materials, and local assessor practice.
- Data used
- 2026 State Tax Commission inflation multiplier and Treasury change-of-ownership guidance
- Last reviewed
- June 8, 2026
- Michigan Treasury change-of-ownership guidance for Proposal A, uncapping, and ownership-transfer rules.
- State Tax Commission inflation rate multipliers for official annual taxable-value cap multipliers.
- State of Michigan property tax estimator for official parcel-oriented property tax estimate.
Use this carefully: Some transfers are exempt or treated differently. Ask the local assessor if the transfer is unusual.
Next steps
Ready to put a number on it?
Uncapping makes more sense when you compare the seller's bill with your estimated first full-year bill.
Calculator
Use the Michigan homebuyer tax calculator
Compare seller tax, buyer tax, and the monthly difference.
Use calculator →Local rates
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Learn mills and Taxable Value
Review the simple terms behind the formula before you use the estimate.
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