Most homeowners wait for PMI to fall off on its own. Three of the four routes out are faster than that, and two of them cost nothing.
Short version: Ask for cancellation the moment your balance hits 80% of the original purchase price. If your home has gained value, an appraisal can get you there years earlier.
Under the federal Homeowners Protection Act, you can ask your servicer to cancel PMI once your balance reaches 80% of the home's original value — the lower of the purchase price or the appraised value at closing. This is a right, not a favor, provided you are current on payments and have no second mortgage on the property.
The request must be in writing. Servicers are not required to remind you, and most do not.
At 78% of the original value, your servicer must cancel PMI on its own. No request, no cost, no appraisal. The catch is that this is the slowest route, typically arriving a year or more after you could have asked at 80%.
There is also a backstop: if you somehow have not reached 78% by the midpoint of your loan term — month 180 of a 30-year loan — PMI must end anyway, as long as you are current.
The first two routes use what you paid for the home. This one uses what it is worth now, which in a rising market is a completely different number.
Fannie Mae and Freddie Mac guidelines generally allow cancellation based on current value when the loan is at least two years old and the balance is 75% or less of the new value, or at least five years old at 80% or less. Your servicer orders the appraisal; you pay for it, usually $300 to $600.
This is the route servicers mention least, and for homeowners who bought before a run-up in prices it is often worth years of premiums.
If your balance is close to 80% of the original price, a single payment can close the gap and end PMI immediately. Whether that makes sense is arithmetic: compare the payment against the premiums you would pay while waiting.
See your own dates
Enter your loan and get all four cancellation routes with the date you qualify for each.
Send it in writing and keep a copy. Note the date, and follow up if you do not hear back within 30 days.
A late payment in the recent past can delay cancellation until your record is clean again. A home equity loan or line of credit counts as a subordinate lien and generally disqualifies you until it is closed. And if your servicer's appraisal comes back lower than you expected, the current-value route closes for the time being.
None of this covers FHA loans. FHA mortgage insurance follows separate rules, and on most FHA loans written since 2013 it cannot be cancelled at all without refinancing.