How property tax works in Montgomery County, from a 1996 assessment to this year's bill

A mill is a dollar, and the assessment is thirty years old

A mill is one dollar of tax per one thousand dollars of assessed value. Forty mills on a $150,000 assessment is $6,000 a year. Simple arithmetic, and the whole difficulty is in the second number.

Montgomery County’s assessments are 1996 values. That is not a rumour — the Pennsylvania Supreme Court said it in Valley Forge Towers Apartments N, LP v. Upper Merion Area School District in 2017, describing Montgomery County as the place “where the most recent countywide assessment of real property occurred in 1996.” Everything on your tax bill is still measured against that year.

A countywide reassessment is a fair question with no published answer. Nothing in the county’s adopted budgets or on its own site says one is planned. That is an absence of evidence, and it should be read as exactly that.

The Common Level Ratio is the translation

The State Tax Equalization Board certified Montgomery County’s ratio at 29.8% on 20 May 2026, and the Pennsylvania Department of Revenue publishes the reciprocal — the factor, 3.36 — for documents accepted 1 July 2026 through 30 June 2027. The year before, the factor was 3.25 on a ratio of 30.76%. The ratio fell, which means assessments slipped further behind the market, which is why the factor rose.

So: assessed value is roughly market value divided by 3.36, or about thirty cents on the dollar. A house selling at $400,000 is likely assessed somewhere near $119,000. Call it an estimate every single time. The ratio is a countywide average built on 2024 sales data, and any one parcel can sit well off it.

For contrast, from the same state list: Bucks 17.86, Chester 3.27, Delaware 1.83, Philadelphia 1.06 through the end of 2026 and 1.00 after. Bucks at 17.86 is what a truly stale base year looks like.

Which is why millage really is comparable inside this county

One base year, one ratio, sixty-two municipalities. That means a mill rate in one Montgomery County town and a mill rate in another describe the same thing, and the spread is genuinely as wide as it looks.

Cheltenham against Upper Merion is twice the rate on the same house, two townships apart. Upper Merion’s low school millage is the King of Prussia Mall and the office parks around it carrying the base.

Across a county line the comparison collapses. Sixty-five mills in Norristown on a $250,000 house works out near $250,000 × 0.298 × 0.065, about $4,840 a year — not the $16,250 a naive reading gives you.

The county’s share, and three straight increases

Every parcel in the county carries the same two county levies: 5.462 mills for the county general fund and 0.49 mills for Montgomery County Community College, 5.952 mills in total. There is no separate library levy and no separate debt-service millage.

The 2026 budget was adopted unanimously on 18 December 2025. The county’s own worked example: an average single-family home at $556,546 of market value and $171,193 assessed pays $935 in county real estate tax plus $84 to the community college, $1,019 for the year. Note that $171,193 ÷ $556,546 is 30.8%, which is the Common Level Ratio turning up in the county’s own arithmetic.

A stale figure of 5.642 circulates in secondary write-ups as the 2026 county rate. That was 2025.

The trap on the county’s own millage sheet

The county publishes one table with the 2026 municipal rate beside the 2026-27 school rate, because school districts run July to June. Two fiscal years in one row, which is fine once you know it.

The real problem is a missing line. Abington School District adopted its 2026-27 budget on 23 June 2026 in two components: a base rate of 39.8992 mills and a referendum millage of 1.3738 mills funding the middle school project, which the Pennsylvania Department of Education approved on 26 March 2026. Abington Township’s own tax office prints both. The county’s millage page prints only the base.

So Abington’s real 2026-27 school rate is 41.2730, and the all-in total is 53.397 mills, not 52.023. Anyone quoting the county sheet alone understates an Abington bill by 1.3738 mills. Expect the same wherever a district carries referendum debt, and take the district’s own number when the two disagree. While we are counting decimals: Abington Township’s page says 6.171 municipal mills and the county says 6.172, one thousandth apart, and nobody has explained it.

Appeals close 1 August, and the ratio decides them

The Board of Assessment Appeals sets the annual filing deadline at 1 August for the following tax year, citing 53 Pa.C.S. §8844(c)(2), and the same date governs applications for tax exemption. Every annual appeal has to be heard and acted on by 31 October, with notice to owners and taxing districts by 15 November, which is why the deadline sits where it does.

The 1 August 2026 deadline has passed. The next annual filing date is 1 August 2027, for tax year 2028. Separately, an interim appeal runs 40 days from the date on a notice of change in assessment, and that is the appeal a buyer of new construction or a recently improved property actually needs.

Practical detail, from the Board’s rules as revised 27 February 2026: the fee for a single-family residential appeal is $50, non-refundable, by check or money order to the Montgomery County Treasurer; three copies of supporting documentation; appeals hand-delivered or postmarked by the last day, and no faxes. The Board warns that changes in USPS operations can delay postmarks, and advises hand-cancellation, a Certificate of Mailing, certified mail, or hand delivery to Norristown.

Now the mechanism, because it is the whole game. Assessments here are set at 1996 values, and the Common Level Ratio is 29.8%. Under 53 Pa.C.S. §8844(e)(2), the board applies the county’s predetermined ratio to market value unless the published Common Level Ratio varies from it by more than 15%, in which case the board applies the Common Level Ratio instead. The variance here is far past that threshold, so the ratio governs, and §8854(a)(3) carries the same rule into Common Pleas. The arithmetic that follows is short: establish today’s market value, multiply by 29.8%, and compare the result to the assessment on the bill. Break-even is the assessment divided by 0.298. A recent arm’s-length purchase price is the strongest evidence there is, and §8854(a)(5) carries a pending appeal forward into later tax years until it is decided.

The Board sits at One Montgomery Plaza, Suite 301, 425 Swede Street in Norristown, mail to P.O. Box 311, Norristown PA 19404-0311, 610-278-3761.

The 1 March line a buyer walks into

The homestead exclusion reduces assessed value, and Act 1 relief applies only to school district taxes. Two deadlines catch people: Act 1 applications are mailed by 1 March, the Act 50 local exclusion by 15 December, and the county advises mailing by 15 December if you want both. Applications go to the county assessment office.

Here is the part that matters at settlement. A buyer who closes after 1 March waits until the following year to qualify, so a first-year school bill can run higher than the seller’s did by the whole value of the exclusion, and nothing on the closing sheet warns you.

One last thing no escrow number includes: the local earned income tax, levied by the municipality and the school district you live in, running from 0.00% to 2.10% across this county.

What to do next

Pull the parcel record, note the assessed value and the municipality, and run the millage yourself before you fall for the house. Then call with the municipality and that assessment, and one licensed Pennsylvania mortgage lender calls you back — usually the same working day, and by the end of the next working day at the outside. Prefer to type it? Put the assessment and the township in the form and send it along. A tax line built from real millage beats a guess by several thousand dollars a year.