The 1999-S Pennsylvania State Quarter is worth anywhere from $3 in lightly circulated condition to over $15 or more for deep cameo proof examples — and certain error coins from this series can push into the hundreds.
If you recently found one of these coins in an old collection or at an estate sale, you’re in the right place. This guide breaks down exactly what the 1999-S Pennsylvania quarter is worth, what makes some examples more valuable than others, and how to spot the details that matter most to collectors.
What Is the 1999-S Pennsylvania State Quarter?
The 1999-S Pennsylvania State Quarter was struck at the San Francisco Mint as part of the 50 State Quarters Program launched by the U.S. Mint in 1999. The “S” mintmark tells you everything — coins with that mark were made specifically for collectors, not for everyday pocket change.
The obverse features George Washington’s portrait, while the reverse shows the Commonwealth keystone symbol, an outline of the state, and the motto “Virtue, Liberty, Independence.” It’s a clean, well-designed coin that kicked off an iconic series.
Because these were proof coins, they were struck multiple times with specially polished dies to give them that sharp, mirror-like finish. They were sold directly to collectors in proof sets, which means most surviving examples are in excellent condition.
If you want to quickly identify your coin and check its grade at home, using the best coin identifier app can save you a lot of time before heading to a dealer.
1999-S Pennsylvania Quarter Value by Grade and Type
Not all 1999-S quarters are the same. There are two main versions: the standard clad proof and the silver proof. The silver version contains 90% silver and is significantly more valuable to collectors who care about precious metal content.
Here’s a quick breakdown of current market values:
| Type | Grade | Estimated Value |
|---|---|---|
| Clad Proof | PR-65 | $3 – $5 |
| Clad Proof Deep Cameo | PR-69 DCAM | $10 – $18 |
| Clad Proof Deep Cameo | PR-70 DCAM | $25 – $50+ |
| Silver Proof | PR-65 | $8 – $12 |
| Silver Proof Deep Cameo | PR-69 DCAM | $15 – $30 |
| Silver Proof Deep Cameo | PR-70 DCAM | $60 – $100+ |
Values can shift based on market demand and certification. For live pricing data on related State Quarter issues, you can check current market prices for the 1999 Delaware State Quarter, which gives you a solid comparison point for the entire 1999 series.
Silver Proof vs. Clad Proof — Does It Really Matter?
Yes, it matters quite a bit. The 1999-S silver proof was only available through a separate silver proof set sold by the U.S. Mint at a premium price. These coins contain 90% silver, which means they carry both numismatic and melt value.
To tell them apart, look at the edge. A silver proof will show a uniform silver-white edge with no copper stripe. A clad coin will have a visible copper layer sandwiched between two outer layers.
Silver proofs consistently sell for two to three times more than their clad counterparts in the same grade. If you’re not sure which version you have, CoinHix makes it easy to identify and compare both types using its built-in coin database and grading tools.
Error Coins and Special Varieties Worth More Money
Error coins are where things get exciting. A small number of 1999-S Pennsylvania quarters were struck with errors during the minting process, and these can be worth significantly more than standard examples.
Some errors to look for include:
– Die cracks — thin raised lines across the coin’s surface caused by a cracked die
– Doubled die — doubling visible on lettering or design elements
– Off-center strikes — the design appears shifted to one side
Even minor errors can increase value by 30% to 100% or more, depending on how dramatic and well-documented they are. If you think you’ve found a variety, get it authenticated by PCGS or NGC before selling.
For a full overview of 1999 quarter values across the board, this detailed 1999 quarter value guide covers all the mintmarks and conditions you’ll want to compare.
How to Get the Best Price for Your 1999-S Pennsylvania Quarter
If you’re thinking about selling, your best options are eBay (for reaching a wide collector audience), coin shows, or a local dealer. Always compare recently sold listings — not just asking prices — to get a realistic number.
Getting your coin professionally graded by PCGS or NGC is worth it if you believe you have a PR-69 or PR-70 specimen, since those grades can fetch premium prices. The grading fee may be $20–$30, but a certified PR-70 can sell for multiples of that.
CoinHix is a great free tool to scan your coin and get an instant grade estimate before committing to professional certification. Many collectors use it as a first step before deciding whether a coin is worth grading costs.
FAQ
Q: How do I know if my 1999-S Pennsylvania quarter is silver or clad?
A: Check the edge of the coin. A silver proof will have a solid silver-white edge with no copper stripe visible. Clad coins show a distinctive copper layer sandwiched between two lighter outer layers. You can also weigh the coin — silver proofs weigh about 6.25 grams, while clad proofs weigh approximately 5.67 grams.
Q: Is a 1999-S Pennsylvania quarter worth getting professionally graded?
A: It depends on its condition. If your coin shows strong cameo contrast and no visible flaws, it may grade PR-69 or PR-70, which can be worth $25 to $100 or more. In those cases, certification pays off. For average PR-65 examples, the grading fee probably isn’t worth it unless it’s the silver version.
Q: Where can I sell my 1999-S Pennsylvania quarter for the best price?
A: eBay is typically the best place because it puts your coin in front of a national collector audience. Search completed listings first to see what similar coins actually sold for. Local coin dealers are faster but usually offer lower prices. CoinHix can also help you understand your coin’s market value before you list it anywhere.
