CPT code 88313: Special stain, group II, tissue constituents2026 Medicare rate & RVUs in King County, WA
Group II histochemical staining highlights tissue features such as fibrosis, iron, or amyloid and is reported once per stain per specimen.
In King County, WA, Medicare pays $97.54 for 88313 in the office.
Check a contract rate as a % of Medicare · 88313 nationwide
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
On this page 11 sections
What 88313 covers
Group II histochemical stains highlight tissue components rather than infectious organisms. Examples include trichrome for fibrosis, Prussian blue for iron, reticulin for tissue architecture, elastic stains for vessel walls, and Congo red for amyloid. Histology staff prepare and stain slides, commonly from paraffin blocks, and a pathologist interprets the findings in the pathology report. These stains may be used on liver biopsies to assess fibrosis or iron, medical kidney biopsies to examine tissue architecture, and cardiac or fat pad biopsies to investigate amyloid.
Report one unit for each distinct Group II stain on each specimen, generally with the applicable tissue examination code, such as 88305 or 88307. The report should identify the specimen, stain, and result. Stains used to identify microorganisms belong in 88312; frozen-section histochemistry and enzyme histochemistry have separate codes. CMS prices the professional interpretation with modifier 26 and the technical preparation, reagents, and staff work with modifier TC. Billing without either modifier represents the global service. Physician work accounts for about 10% of the office total.
This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.
How King County, WA compares for 88313
Across 109 of 109 payment localities, the office rate for 88313 runs from $70.29 in Arkansas to $113.40 in San Benito County, CA. King County, WA pays $97.54. The RVUs are the same everywhere; the geographic indexes change the dollars.
- King County, WA · this page$97.54
- Rest of Washington · Washington$84.61−$12.93
- Los Angeles, CA · California$94.18−$3.36
- Washington, DC area · District of Columbia$94.22−$3.32
- Miami, FL · Florida$84.82−$12.72
- Chicago, IL · Illinois$82.11−$15.43
- Manhattan, NY · New York$93.46−$4.08
Other areas in Washington first, then benchmark localities. Bars start at $0.
Every other payment area
| Payment locality | Office | Facility |
|---|---|---|
| AlaskaAlaska | $89.08 | — |
| AlabamaAlabama | $71.48 | — |
| ArkansasArkansas | $70.29 | — |
| ArizonaArizona | $78.49 | — |
| Bakersfield, CACalifornia | $87.67 | — |
| Chico, CACalifornia | $87.61 | — |
| El Centro, CACalifornia | $87.61 | — |
| Fresno, CACalifornia | $87.61 | — |
| Hanford, CACalifornia | $87.61 | — |
| Madera, CACalifornia | $87.61 | — |
| Merced, CACalifornia | $87.61 | — |
| Modesto, CACalifornia | $87.61 | — |
| Napa, CACalifornia | $104.03 | — |
| Oxnard, CACalifornia | $93.98 | — |
| Redding, CACalifornia | $87.61 | — |
| Rest of CaliforniaCalifornia | $87.61 | — |
| Riverside, CACalifornia | $87.83 | — |
| Sacramento, CACalifornia | $92.61 | — |
| Salinas, CACalifornia | $92.28 | — |
| San Diego, CACalifornia | $94.96 | — |
| Marin County, CACalifornia | $110.92 | — |
| San Francisco, CACalifornia | $110.89 | — |
| San Benito County, CACalifornia | $113.40 | — |
| Santa Clara County, CACalifornia | $113.31 | — |
| San Luis Obispo, CACalifornia | $90.73 | — |
| Santa Cruz, CACalifornia | $96.26 | — |
| Santa Maria, CACalifornia | $92.77 | — |
| Santa Rosa, CACalifornia | $97.28 | — |
| Stockton, CACalifornia | $87.61 | — |
| Vallejo, CACalifornia | $104.00 | — |
| Visalia, CACalifornia | $87.61 | — |
| Yuba City, CACalifornia | $87.61 | — |
| ColoradoColorado | $85.41 | — |
| ConnecticutConnecticut | $86.71 | — |
| DelawareDelaware | $79.93 | — |
| Fort Lauderdale, FLFlorida | $82.31 | — |
| Rest of FloridaFlorida | $77.98 | — |
| Atlanta, GAGeorgia | $82.15 | — |
| Rest of GeorgiaGeorgia | $73.13 | — |
| Hawaii, Guam, HIHawaii | $90.48 | — |
| IowaIowa | $74.27 | — |
| IdahoIdaho | $74.68 | — |
| East St. Louis, ILIllinois | $75.71 | — |
| Rest of IllinoisIllinois | $74.90 | — |
| Suburban Chicago, ILIllinois | $83.36 | — |
| IndianaIndiana | $75.20 | — |
| KansasKansas | $73.54 | — |
| KentuckyKentucky | $72.73 | — |
| New Orleans, LALouisiana | $76.64 | — |
| Rest of LouisianaLouisiana | $72.47 | — |
| Metropolitan Boston, MAMassachusetts | $95.13 | — |
| Rest of MassachusettsMassachusetts | $84.66 | — |
| Baltimore area, MDMaryland | $86.40 | — |
| Rest of MarylandMaryland | $81.72 | — |
| Rest of MaineMaine | $74.78 | — |
| Southern Maine, MEMaine | $79.93 | — |
| Detroit, MIMichigan | $78.75 | — |
| Rest of MichiganMichigan | $74.61 | — |
| MinnesotaMinnesota | $82.46 | — |
| Metropolitan Kansas City, MOMissouri | $76.39 | — |
| Metropolitan St. Louis, MOMissouri | $77.35 | — |
| Rest of MissouriMissouri | $70.81 | — |
| MississippiMississippi | $70.58 | — |
| MontanaMontana | $80.83 | — |
| North CarolinaNorth Carolina | $75.73 | — |
| North DakotaNorth Dakota | $80.43 | — |
| NebraskaNebraska | $74.83 | — |
| New HampshireNew Hampshire | $83.72 | — |
| Northern New JerseyNew Jersey | $92.96 | — |
| Rest of New JerseyNew Jersey | $87.87 | — |
| New MexicoNew Mexico | $74.95 | — |
| NevadaNevada | $80.79 | — |
| NYC suburbs and Long Island, NYNew York | $95.59 | — |
| Poughkeepsie and northern NYC suburbs, NYNew York | $88.20 | — |
| Queens, NYNew York | $94.81 | — |
| Rest of New YorkNew York | $77.01 | — |
| OhioOhio | $74.53 | — |
| OklahomaOklahoma | $72.93 | — |
| Portland, OROregon | $88.83 | — |
| Rest of OregonOregon | $80.34 | — |
| Metropolitan Philadelphia, PAPennsylvania | $84.07 | — |
| Rest of PennsylvaniaPennsylvania | $74.85 | — |
| Puerto RicoPuerto Rico | $81.62 | — |
| Rhode IslandRhode Island | $83.30 | — |
| South CarolinaSouth Carolina | $75.22 | — |
| South DakotaSouth Dakota | $80.39 | — |
| TennesseeTennessee | $73.93 | — |
| Austin, TXTexas | $84.97 | — |
| Beaumont, TXTexas | $74.26 | — |
| Brazoria, TXTexas | $80.09 | — |
| Dallas, TXTexas | $80.51 | — |
| Fort Worth, TXTexas | $79.80 | — |
| Galveston, TXTexas | $80.27 | — |
| Houston, TXTexas | $80.64 | — |
| Rest of TexasTexas | $77.07 | — |
| UtahUtah | $76.41 | — |
| VirginiaVirginia | $79.40 | — |
| Virgin Islands, VIUnited States Virgin Islands | $81.62 | — |
| VermontVermont | $79.78 | — |
| WisconsinWisconsin | $77.32 | — |
| West VirginiaWest Virginia | $71.62 | — |
| WyomingWyoming | $80.66 | — |
88313 rates by state
Office rate range in each state. Select a state to see its payment localities.
Explore a state
Local rates. Clear comparisons.
Hover or focus a tile to see its rate range. Select it to open the state’s fee schedule.
$70.29
$100.51
Color shows the midpoint of each state’s locality range.
View every state and territory as a table
| State / territory | Office rate range | Localities |
|---|---|---|
| AK | $89.08 | 1 |
| AL | $71.48 | 1 |
| AR | $70.29 | 1 |
| AZ | $78.49 | 1 |
| CA | $87.61–$113.40 | 29 |
| CO | $85.41 | 1 |
| CT | $86.71 | 1 |
| DC | $94.22 | 1 |
| DE | $79.93 | 1 |
| FL | $77.98–$84.82 | 3 |
| GA | $73.13–$82.15 | 2 |
| GU | $90.48 | 1 |
| HI | $90.48 | 1 |
| IA | $74.27 | 1 |
| ID | $74.68 | 1 |
| IL | $74.90–$83.36 | 4 |
| IN | $75.20 | 1 |
| KS | $73.54 | 1 |
| KY | $72.73 | 1 |
| LA | $72.47–$76.64 | 2 |
| MA | $84.66–$95.13 | 2 |
| MD | $81.72–$94.22 | 3 |
| ME | $74.78–$79.93 | 2 |
| MI | $74.61–$78.75 | 2 |
| MN | $82.46 | 1 |
| MO | $70.81–$77.35 | 3 |
| MS | $70.58 | 1 |
| MT | $80.83 | 1 |
| NC | $75.73 | 1 |
| ND | $80.43 | 1 |
| NE | $74.83 | 1 |
| NH | $83.72 | 1 |
| NJ | $87.87–$92.96 | 2 |
| NM | $74.95 | 1 |
| NV | $80.79 | 1 |
| NY | $77.01–$95.59 | 5 |
| OH | $74.53 | 1 |
| OK | $72.93 | 1 |
| OR | $80.34–$88.83 | 2 |
| PA | $74.85–$84.07 | 2 |
| PR | $81.62 | 1 |
| RI | $83.30 | 1 |
| SC | $75.22 | 1 |
| SD | $80.39 | 1 |
| TN | $73.93 | 1 |
| TX | $74.26–$84.97 | 8 |
| UT | $76.41 | 1 |
| VA | $79.40–$94.22 | 2 |
| VI | $81.62 | 1 |
| VT | $79.78 | 1 |
| WA | $84.61–$97.54 | 2 |
| WI | $77.32 | 1 |
| WV | $71.62 | 1 |
| WY | $80.66 | 1 |
How the 88313 rate is calculated
Each of 88313’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.
How the rate is built · 88313
RVUs × geographic indexes × conversion factor
Work0.23
0.23 RVUs× 1.000 GPCI
Practice expense2.17
2.17 RVUs× 1.000 GPCI
Malpractice0.02
0.02 RVUs× 1.000 GPCI
Adjusted RVUs
2.4200
Conversion factor
$33.4009
Medicare rate
$80.83
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
The exact King County, WA inputs and CMS source lines
PPRRVU2026_Oct_nonQPP.csv
11,221
- Code
- 88313
- Physician work
- 0.23
- Practice expense
- 2.17
- Malpractice
- 0.02
GPCI2026.csv
108
- Locality
- King County, WA
- Physician work
- 1.050
- Practice expense
- 1.227
- Malpractice
- 0.817
| Component | RVU | Locality factor | Adjusted |
|---|---|---|---|
| Physician work | 0.23 | × 1.050 | 0.2415 |
| Practice expense | 2.17 | × 1.227 | 2.6626 |
| Malpractice | 0.02 | × 0.817 | 0.0163 |
| Total RVUs | 2.9204 | ||
| Conversion factor | × 33.4009 | ||
Office rate, King County, WA$97.54
Office: (0.23 × 1.05 + 2.17 × 1.227 + 0.02 × 0.817) × $33.4009 = $97.54
Payment rules and modifiers for 88313
The CMS indicators that decide how 88313 is paid alongside other services.
CMS payment indicators · 88313
Special stain, group II, tissue constituents
| Rule | CMS value | What it means |
|---|---|---|
| Global period | XXX | The global surgery concept doesn’t apply. |
| Multiple procedures | 0 | No multiple-procedure reduction. |
| Bilateral (modifier 50) | 0 | The 150% bilateral adjustment doesn’t apply. |
| Assistant at surgery (80/81/82/AS) | 0 | Not paid without supporting documentation. |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 1 | Diagnostic test with separate professional (26) and technical (TC) components. |
What modifiers do to the payment
Modifier 26 · payment effect
With and without the modifier
88313 without 26 · national office
$80.83
Special stain, group II, tissue constituents
88313-26 · Professional component
$11.36
Pays only the interpretation and report.
How 88313 has changed in King County, WA
88313 · Office / nonfacility
$97.54
Effective 2026-10-01
The base rate is $2.07 higher than on 2025-10-01, moving from $95.47 to $97.54 (2.2%).
It is unchanged from the immediately preceding available release, effective 2026-07-01.
One bar per available release, ordered by effective date. Missing rates remain gaps. These comparisons hold the code, setting and locality identifiers constant; they do not isolate which policy or input caused a change.
What changed, release by release
January 1, 2026
RVU26A
$95.47changed to$97.54
- Conversion factor 32.3465 changed to 33.4009
- Work RVU 0.24 changed to 0.23
- Practice expense RVU 2.20 changed to 2.17
- Work GPCI 1.043 changed to 1.050
- Practice expense GPCI 1.220 changed to 1.227
- Malpractice GPCI 0.853 changed to 0.817
Held through RVU26B, RVU26C, RVU26D.
January 1, 2025
RVU25A
$99.46changed to$95.47
- Conversion factor 33.2875 changed to 32.3465
- Practice expense RVU 2.23 changed to 2.20
Held through RVU25B, RVU25C, RVU25D.
March 9, 2024
RVU24AR
$97.84changed to$99.46
- Conversion factor 32.7442 changed to 33.2875
Held through RVU24B, RVU24C, RVU24D.
January 1, 2024
RVU24A
$98.17changed to$97.84
- Conversion factor 33.8872 changed to 32.7442
- Practice expense RVU 2.18 changed to 2.23
- Work GPCI 1.039 changed to 1.043
- Practice expense GPCI 1.207 changed to 1.220
- Malpractice GPCI 0.815 changed to 0.853
January 1, 2023
RVU23A
$96.74changed to$98.17
- Conversion factor 34.6062 changed to 33.8872
- Practice expense RVU 2.12 changed to 2.18
- Work GPCI 1.036 changed to 1.039
- Practice expense GPCI 1.194 changed to 1.207
- Malpractice GPCI 0.776 changed to 0.815
Held through RVU23B, RVU23C, RVU23D.
January 1, 2022
RVU22A
$95.88changed to$96.74
- Conversion factor 34.8931 changed to 34.6062
- Practice expense RVU 2.08 changed to 2.12
Held through RVU22B, RVU22C, RVU22D.
January 1, 2021
RVU21A
$88.93changed to$95.88
- Conversion factor 36.0896 changed to 34.8931
- Practice expense RVU 1.88 changed to 2.08
- Work GPCI 1.031 changed to 1.036
- Practice expense GPCI 1.170 changed to 1.194
- Malpractice GPCI 0.854 changed to 0.776
Held through RVU21B, RVU21C, RVU21D.
January 1, 2020
RVU20A
$83.48changed to$88.93
- Conversion factor 36.0391 changed to 36.0896
- Practice expense RVU 1.79 changed to 1.88
- Work GPCI 1.027 changed to 1.031
- Practice expense GPCI 1.146 changed to 1.170
- Malpractice GPCI 0.931 changed to 0.854
Held through RVU20B, RVU20C, RVU20D.
January 1, 2019
RVU19A
$81.33changed to$83.48
- Conversion factor 35.9996 changed to 36.0391
- Practice expense RVU 1.74 changed to 1.79
Held through RVU19B, RVU19C, RVU19D.
January 1, 2018
RVU18AR1
$79.99changed to$81.33
- Conversion factor 35.8887 changed to 35.9996
- Practice expense RVU 1.71 changed to 1.74
- Work GPCI 1.026 changed to 1.027
- Practice expense GPCI 1.151 changed to 1.146
- Malpractice GPCI 0.713 changed to 0.931
Held through RVU18B, RVU18C, RVU18D.
January 1, 2017
RVU17A
$78.22changed to$79.99
- Conversion factor 35.8043 changed to 35.8887
- Practice expense RVU 1.67 changed to 1.71
- Work GPCI 1.025 changed to 1.026
- Practice expense GPCI 1.155 changed to 1.151
- Malpractice GPCI 0.495 changed to 0.713
Held through RVU17B, RVU17C, RVU17D.
January 1, 2016
RVU16A
$77.26changed to$78.22
- Conversion factor 35.9335 changed to 35.8043
- Practice expense RVU 1.64 changed to 1.67
Held through RVU16B, RVU16C, RVU16D.
July 1, 2015
RVU15C
$76.88changed to$77.26
- Conversion factor 35.7547 changed to 35.9335
Held through RVU15D.
January 1, 2015
RVU15A
$74.40changed to$76.88
- Conversion factor 35.8228 changed to 35.7547
- Practice expense RVU 1.58 changed to 1.64
- Practice expense GPCI 1.150 changed to 1.155
- Malpractice GPCI 0.688 changed to 0.495
Held through RVU15B.
January 1, 2014
RVU14A
$76.30changed to$74.40
- Conversion factor 34.0230 changed to 35.8228
- Practice expense RVU 1.73 changed to 1.58
- Practice expense GPCI 1.144 changed to 1.150
- Malpractice GPCI 0.881 changed to 0.688
Held through RVU14B, RVU14C, RVU14D.
January 1, 2013
RVU13AR
Earliest loaded release: $76.30
Held through RVU13B, RVU13C, RVU13D.
| Effective from | Office | Facility | CMS release |
|---|---|---|---|
| 2026-10-01 | $97.54 | Not available in this setting | RVU26D |
| 2026-07-01 | $97.54 | Not available in this setting | RVU26C |
| 2026-04-01 | $97.54 | Not available in this setting | RVU26B |
| 2026-01-01 | $97.54 | Not available in this setting | RVU26A |
| 2025-10-01 | $95.47 | Not available in this setting | RVU25D |
| 2025-07-01 | $95.47 | Not available in this setting | RVU25C |
| 2025-04-01 | $95.47 | Not available in this setting | RVU25B |
| 2025-01-01 | $95.47 | Not available in this setting | RVU25A |
| 2024-10-01 | $99.46 | Not available in this setting | RVU24D |
| 2024-07-01 | $99.46 | Not available in this setting | RVU24C |
| 2024-04-01 | $99.46 | Not available in this setting | RVU24B |
| 2024-03-09 | $99.46 | Not available in this setting | RVU24AR |
| 2024-01-01 | $97.84 | Not available in this setting | RVU24A |
| 2023-10-01 | $98.17 | Not available in this setting | RVU23D |
| 2023-07-01 | $98.17 | Not available in this setting | RVU23C |
| 2023-04-01 | $98.17 | Not available in this setting | RVU23B |
| 2023-01-01 | $98.17 | Not available in this setting | RVU23A |
| 2022-10-01 | $96.74 | Not available in this setting | RVU22D |
| 2022-07-01 | $96.74 | Not available in this setting | RVU22C |
| 2022-04-01 | $96.74 | Not available in this setting | RVU22B |
| 2022-01-01 | $96.74 | Not available in this setting | RVU22A |
| 2021-10-01 | $95.88 | Not available in this setting | RVU21D |
| 2021-07-01 | $95.88 | Not available in this setting | RVU21C |
| 2021-04-01 | $95.88 | Not available in this setting | RVU21B |
| 2021-01-01 | $95.88 | Not available in this setting | RVU21A |
| 2020-10-01 | $88.93 | Not available in this setting | RVU20D |
| 2020-07-01 | $88.93 | Not available in this setting | RVU20C |
| 2020-04-01 | $88.93 | Not available in this setting | RVU20B |
| 2020-01-01 | $88.93 | Not available in this setting | RVU20A |
| 2019-10-01 | $83.48 | Not available in this setting | RVU19D |
| 2019-07-01 | $83.48 | Not available in this setting | RVU19C |
| 2019-04-01 | $83.48 | Not available in this setting | RVU19B |
| 2019-01-01 | $83.48 | Not available in this setting | RVU19A |
| 2018-10-01 | $81.33 | Not available in this setting | RVU18D |
| 2018-07-01 | $81.33 | Not available in this setting | RVU18C |
| 2018-04-01 | $81.33 | Not available in this setting | RVU18B |
| 2018-01-01 | $81.33 | Not available in this setting | RVU18AR1 |
| 2017-10-01 | $79.99 | Not available in this setting | RVU17D |
| 2017-07-01 | $79.99 | Not available in this setting | RVU17C |
| 2017-04-01 | $79.99 | Not available in this setting | RVU17B |
| 2017-01-01 | $79.99 | Not available in this setting | RVU17A |
| 2016-10-01 | $78.22 | Not available in this setting | RVU16D |
| 2016-07-01 | $78.22 | Not available in this setting | RVU16C |
| 2016-04-01 | $78.22 | Not available in this setting | RVU16B |
| 2016-01-01 | $78.22 | Not available in this setting | RVU16A |
| 2015-10-01 | $77.26 | Not available in this setting | RVU15D |
| 2015-07-01 | $77.26 | Not available in this setting | RVU15C |
| 2015-04-01 | $76.88 | Not available in this setting | RVU15B |
| 2015-01-01 | $76.88 | Not available in this setting | RVU15A |
| 2014-10-01 | $74.40 | Not available in this setting | RVU14D |
| 2014-07-01 | $74.40 | Not available in this setting | RVU14C |
| 2014-04-01 | $74.40 | Not available in this setting | RVU14B |
| 2014-01-01 | $74.40 | Not available in this setting | RVU14A |
| 2013-10-01 | $76.30 | Not available in this setting | RVU13D |
| 2013-07-01 | $76.30 | Not available in this setting | RVU13C |
| 2013-04-01 | $76.30 | Not available in this setting | RVU13B |
| 2013-01-01 | $76.30 | Not available in this setting | RVU13AR |
Where the King County, WA rate applies
King County, WA is a Medicare payment area, not a city. Our Census mapping connects it to 63 cities and communities in Washington. Some span more than one payment area; confirm with the service ZIP.
- Seattle
- Algona
- Ames Lake
- 88313 in Auburn · multiple payment areas
- Baring
- Beaux Arts Village
- Bellevue
- Black Diamond
88313 billing questions
How many units are reported when several Group II stains are performed?
Report one unit per distinct stain per specimen. A liver biopsy with trichrome and iron stains supports two units; the same stain on two separately submitted specimens also supports two units.
When is 88312 used instead of 88313?
Use 88312 for a stain performed to identify microorganisms, such as a fungal, acid-fast, or Gram stain. Use 88313 for stains demonstrating tissue constituents such as collagen, iron, glycogen, elastic fibers, or amyloid.
Does the stain's purpose matter if the same stain can serve either group?
Yes. A PAS stain used to look for fungi is reported with 88312, while PAS used to evaluate glycogen or basement membranes is reported with 88313.
Is the routine H&E slide separately reportable with 88313?
No. Routine H&E staining is included in the gross and microscopic surgical pathology examination. Report 88313 for a separately performed Group II special stain.
How are modifiers 26 and TC applied?
A pathologist who interprets a slide stained by another entity bills 88313 with modifier 26. The entity providing only slide preparation and staining bills with modifier TC; an entity providing both components bills without either modifier.
What documentation supports each unit?
The pathology report should identify each stain and specimen and describe the result or its diagnostic significance. An order without a reported interpretation does not support billing the professional component.
Where these rates come from
FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.
CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027
Show the CMS file lines behind this rate
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