How Medicare Sets Different Rates by ZIP Code
Medicare splits the country into 109 payment localities. Each one has three cost indexes, called GPCIs, for physician work, practice expense and malpractice. Medicare multiplies each part of a code's RVUs by the local index, adds them up, and multiplies by the conversion factor.
So the same code pays more in Manhattan than in rural Arkansas. CMS publishes a file that ties every ZIP code to its locality. This tool uses the October 2026 version of that file, with 42,957 ZIP codes.
| Year | Conversion factor | What changed |
|---|---|---|
| 2026 | $33.4009 ($33.5675 for qualifying APM participants) | Current rates |
| 2027 (final rule) | $32.6286 ($32.9548 for qualifying APM participants) | About 2.3% lower factor; the work GPCI floor of 1.0 ends, so 49 localities fall below 1.0 |
Example: What Percent of Medicare Is an Offer?
Say a payer offers $82 for 99214 in Atlanta. The 2026 Medicare office rate there is $137.81, so the offer is about 59.5% of Medicare. For 99213 the Atlanta rate is $96.71.
Commercial contracts are often written as a percent of Medicare, such as 110% or 125%. Compare offers code by code for the services you bill most, in the right setting. A rate that looks fine for one code can be low for another. Our underpayment calculator can check what you were actually paid.
ZIP Codes That Cross Two Localities
About 480 ZIP codes are split between localities, mostly in Massachusetts, New York, New Jersey, Pennsylvania and a few other states. For these, CMS uses the full ZIP+4 code. The tool lists each locality the ZIP code touches so you can pick yours. Your MAC can confirm which one applies to your address.
What This Tool Does Not Cover
- Labs (Clinical Lab Fee Schedule), drugs, DME and ambulance use other Medicare fee schedules.
- Some codes are bundled, priced by your MAC, or not covered, so they have no fee schedule amount.
- Multiple procedure, bilateral and assistant surgeon cuts are not applied. See our MPPR calculator.
- The 2% sequestration cut comes off Medicare's 80% share when it pays. See our sequestration calculator.
Sources: CMS Zip Code to Carrier Locality File (October 2026 quarter, updated August 13, 2026); CMS CY 2026 Physician Fee Schedule RVU26D (PPRRVU, GPCI, OPPS cap); CMS CY 2027 Physician Fee Schedule final rule (CMS-1848-F).
Frequently Asked Questions
Written by Hassan Raza Awan
Founder — LegitMedBilling & IT Solutions
Hassan has 4+ years of hands-on U.S. medical billing experience — working claims, denials, credentialing, and payer follow-up for practices across the United States. Every guide he publishes is written from real remittances and payer behavior, not theory.
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