Update: This post is a work in progress as every step takes quite some time. As of early February, I’ve submitted a Written Appeal given what ChatGPT has provided and will update this post with the results when they come in.
In Maryland, your home is assessed every three years and your property taxes are based on that assessment. We last dealt with this in 2023 and the appeal was successful.
I contested it based on Qualify Factor, which was a multiplier used on our base assessment. The state felt we were a 6, which meant you multiplied your base value by 1.37. We lowered it to a 5, which is a multiplier of 1.17. That resulted in big savings (20%!).
This year, we can’t do that because we’re still at a Qualify Factor of 5.
Three years ago, I spent a few hours learning how it all worked but this time, I wanted to see if ChatGPT could give me a hand. I know the process of an appeal but ChatGPT could give me insight into how it all really worked… and it delivered. And I filed an appeal in about ten minutes.
First, I requested our Residential Worksheet and the Comparable Sales List used for my assessment from Maryland. Then, I fed the documents into ChatGPT and had it analyze my chances and tell me exactly what to do.
📒 If you want to contest your taxes but don’t want to do it yourself, Ownwell may be able to help. If available in your state, they can contest it for you and you only pay a percentage of what they save you in taxes. Nothing up front.
Table of Contents
ChatGPT Identified Appeal Targets
The Residential Worksheet gave ChatGPT enough information about our property to compare it with the sales list and see if there were areas we could contest.
Here’s what it said about the comparable sales:
Your Area Sales Listing (Neighborhood XXXXXXXX.XX) is gold
Here’s what jumps out immediately from that sheet:
A. Recent Sales Cluster Lower Than Your Assessment
Many 2023–2025 arms-length sales in your exact neighborhood code show:
- Sale prices commonly between:
$775k – $1.05M- Several large-lot properties (5–10 acres) selling well below your assessed value
- Homes with:
- Similar vintage (1970s–1990s)
- Similar or larger living area
- Similar acreage
- Often equal or better quality ratings
Yet SDAT places you at $1.3M.
That gap is the core of your appeal.
For context, we live in an area where large lot properties tend to be much older because they pre-date the massive amount of building that has happened the last twenty or thirty years. Most of the new single-family homes now are on half acre lots or, at most, three acre lots.
We’re a house built in 1990 on 10 acres and it’s only so many acres because it’s uneven, woody, and (lucky for us) too expensive to subdivide and build.
So if you know the area, this is all true and the valuable argument plausible.
ChatGPT also identified likely errors:
3. Likely Assessment Errors / Pressure Points
These are the arguments that typically land:
🔹 1. Overstated Market Adjustment Factors
SDAT applied:
- County Multiplier: 1.60
- Quality Factor: 1.17
- Neighborhood Adjustment: 1.10
👉 Combined, these inflate base cost dramatically.
Your comps suggest market prices did NOT rise at that rate for similar homes.
ChatGPT also picked out a few line items that seemed aggressively high – like a finished basement valuation and pool.
ChatGPT even gave you a sense of what could be saved:
5. What a Realistic Win Looks Like
Typical successful outcomes in Howard County:
- 5–15% reduction at Supervisor level
- On your assessment:
- 10% = ~$136,000 reduction
- That’s real tax savings every year
If Supervisor review fails, you can escalate to:
- Property Tax Assessment Appeals Board (PTAAB)
…but most people never need to.
Submitting a Written Appeal
If you don’t know how to appeal your property taxes, ChatGPT can give you step by step instructions.
The first step in Maryland’s appeal process is to go to the online appeal portal and file a written appeal, often known as a Supervisor’s Review.
In Maryland, it’s an online form with a simple text box. ChatGPT can put together a cover letter with attachments (like the sales list with highlighting to identify actual comps) if your state allows it.
For now, I will simply ask ChatGPT for what to paste into the form and this is what it suggested:
I am requesting a Supervisor’s Review because the assessed market value of my property appears overstated.
The current total assessed value is $1,300,000 ($400,000 land and $900,000 improvements). Based on recent arms-length sales within Neighborhood Code XXXXXXX.XX, properties with similar age, quality, acreage, and living area have sold for materially less than my assessment.
Multiple comparable sales from 2023–2025 in this neighborhood show market values significantly below my assessed value, including homes of similar size (approximately 3,500–4,500 sq ft) on large acreage (5–10+ acres). These sales suggest that the applied county multiplier and neighborhood adjustment exceed observed market pricing.
In addition, contributory value assigned to certain features (finished basement and in-ground pool) appears higher than supported by market data, as comparable properties do not demonstrate proportional price premiums for these items.
Based on these comparable sales, I believe a more accurate market value as of the assessment date is $__________. I respectfully request a review and adjustment to align the assessment with actual market value.
I am happy to provide a detailed comparable-sales grid, photographs, and supporting documentation upon request.
Note the blank – ChatGPT suggested different values based on how conservative or aggressive I wanted to be. I said aggressive and list 3-5 comps as examples… because you don’t get what you don’t ask for!
Here’s how ChatGPT updated the note:
I am requesting a Supervisor’s Review because the assessed market value of my property appears overstated.
The current total assessed value is $1,300,000 ($400,000 land and $900,000 improvements). Based on recent arms-length sales within Neighborhood Code XXXXXXX.XX, properties with similar age, quality, acreage, and living area have sold for materially less than my assessment.
Comparable neighborhood sales from 2023–2025 include:
• Sale in March 2024 for approximately $775,000 (improved property on acreage)
• Sale in June 2024 for approximately $850,000
• Sale in September 2024 for approximately $900,000
• Sale in March 2025 for approximately $1,050,000
• Sale in June 2025 for approximately $1,100,000These properties are located within the same neighborhood code and reflect market prices well below my assessed value, despite similar characteristics. The applied county multiplier and neighborhood adjustment therefore appear to overstate current market conditions.
In addition, contributory value assigned to certain features (including the finished basement and in-ground pool) appears higher than supported by market evidence, as comparable properties do not demonstrate proportional price premiums for these items.
Based on these comparable sales, I believe a more accurate market value as of the assessment date is $1,160,000, and I respectfully request an adjustment to reflect actual market value. Supporting comparable sales data and documentation are available upon request.
And that’s what I submitted. We will see what the board says!
Appeal Results [TBD]
It will take quite some time for Maryland to respond to my request, especially given all the other appeals, but I will update this section with their response and what I will do next.
They did send this message a few days after I submitted my appeal:
This email is to confirm the receipt of your residential property written appeal. Our office will consider the information you have provided to determine your property’s final market value. We have attached your property record card; please review for any incorrect information. If you discover any incorrect information, please contact our office as soon as possible so your property record card can be corrected while determining the final market valuation of your property. A sales listing has also been attached to keep with your appeal records.
Once your appeal is reviewed you will receive a Final Notice by mail. Our office makes every attempt to complete all hearings by June 1. However, depending on the volume of appeals, it is possible you may receive your Final Notice after June 1.
Potentially after June 1st! Wow.
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