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Billing code 27310: Knee arthrotomyMedicare rate & RVUs

Reports open knee-joint access to investigate a joint problem, drain infection, or remove an intra-articular foreign body during surgery.

CMS RVU26DEffective Oct 1, 2026109 payment localities5.6K Medicare services in 2024

Medicare pays $689.06 for 27310 nationally in a facility.

Medicare rate · 27310

Knee arthrotomy

Swap in your local Medicare rate.

Work RVUs
9.75
Total RVUs
20.63
Global days
090

National rate · 2026

$689.06

Facility setting, before claim adjustments.

See every locality for 27310 → · Billed by an NP, PA or therapist? →

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 10 sections
  1. Medicare rate
  2. What 27310 covers
  3. By payment locality
  4. Rate map
  5. How it’s calculated
  6. Payment rules
  7. Similar codes
  8. Related codes
  9. Billing questions
  10. Sources

What 27310 covers

An orthopedic surgeon opens the knee joint to inspect its interior, drain infected material, or remove a foreign object. A typical setting is the operating room, including surgery for a suspected or confirmed septic knee joint. The procedure is open: it is not the arthroscopic approach used to inspect or treat the joint through small portals.

Report 27310 when the operative work is open exploration, drainage, or foreign-body removal, and document the approach, indication, intra-articular findings, and work performed. The code has a 90-day global period, which includes the day-before preoperative visit and 90 days of related postoperative care. When multiple procedures occur in the same session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% reduction. Bilateral reporting with modifier 50 is paid at 150%. An assistant at surgery may be paid; co-surgeon payment requires supporting documentation, and team surgery is not permitted.

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.

Where 27310 pays more and less

The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.

109 of 109 payment localities

27310 office and facility rates by payment locality
Payment localityOfficeFacility
AlabamaUnavailable$622.48
Alaska*Unavailable$840.32
ArizonaUnavailable$670.06
ArkansasUnavailable$614.27
AtlantaUnavailable$708.52
AustinUnavailable$699.01
BakersfieldUnavailable$696.79
Baltimore/Surr. CntysUnavailable$732.03
BeaumontUnavailable$657.66
BrazoriaUnavailable$673.95

27310 rates by state

Office rate range in each state. Select a state to see its payment localities.

MEWIVTNHMTNDMNMINYMARIWAIDWYSDIAILINOHPANJCTORNVUTCONEMOKYWVVAMDDECAAZNMKSOKARTNNCSCDCTXLAMSALGAFLAKHI

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Local rates. Clear comparisons.

Hover or focus a tile to see its rate range. Select it to open the state’s fee schedule.

View every state and territory as a table
27310 office rate range by state
State / territoryOffice rate rangeLocalities
AKNo published base rate1
ALNo published base rate1
ARNo published base rate1
AZNo published base rate1
CANo published base rate29
CONo published base rate1
CTNo published base rate1
DCNo published base rate1
DENo published base rate1
FLNo published base rate3
GANo published base rate2
GUNo published base rate1
HINo published base rate1
IANo published base rate1
IDNo published base rate1
ILNo published base rate4
INNo published base rate1
KSNo published base rate1
KYNo published base rate1
LANo published base rate2
MANo published base rate2
MDNo published base rate3
MENo published base rate2
MINo published base rate2
MNNo published base rate1
MONo published base rate3
MSNo published base rate1
MTNo published base rate1
NCNo published base rate1
NDNo published base rate1
NENo published base rate1
NHNo published base rate1
NJNo published base rate2
NMNo published base rate1
NVNo published base rate1
NYNo published base rate5
OHNo published base rate1
OKNo published base rate1
ORNo published base rate2
PANo published base rate2
PRNo published base rate1
RINo published base rate1
SCNo published base rate1
SDNo published base rate1
TNNo published base rate1
TXNo published base rate8
UTNo published base rate1
VANo published base rate2
VINo published base rate1
VTNo published base rate1
WANo published base rate2
WINo published base rate1
WVNo published base rate1
WYNo published base rate1

How the 27310 rate is calculated

Each of 27310’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 · 27310

RVUs × geographic indexes × conversion factor

Swap in your local Medicare rate.

Work 9.75Practice expense 8.83Malpractice 2.05

20.6300 adjusted RVUs×$33.4009 conversion factor=$689.06

All indexes start at 1.000 (the national rate). Enter a ZIP or drag a slider.

Payment rules and modifiers for 27310

27310 has a 90-day global period: related visits in that window are included in the surgery payment.

CMS payment indicators · 27310

Knee arthrotomy

RuleCMS valueWhat it means
Global period090Major surgery: the day before, the day of, and 90 days after are included.
Multiple procedures2Standard reduction: highest-valued procedure at 100%, others at 50%.
Bilateral (modifier 50)1Bilateral with modifier 50 pays 150% of the fee schedule amount.
Assistant at surgery (80/81/82/AS)2Paid.
Co-surgeons (62)1Permitted with supporting documentation.
Team surgery (66)0Not permitted.
Professional/technical0Physician service: no professional/technical split.
Split (54/55/56)0.10/0.69/0.21Share of the payment for pre-op, the procedure itself, and post-op care.

Global surgery period · 27310

Knee arthrotomy

90-day global period ends

Dec 30, 2026

Covers Sep 30, 2026 through Dec 30, 2026 (92 days, including the day before surgery).

Visit on Oct 31, 2026

Day 30 of the 90-day post-op period: related follow-up care is included in the surgical payment.

  • 24 Unrelated E/M visit by the same physician
  • 79 Unrelated procedure (starts its own global period)
  • 58 Staged, more extensive, or therapy procedure that was planned
  • 78 Unplanned return to the operating room for a related complication
SurgeryVisit
Sep 23, 2026Jan 10, 2027

Pre-op dayGlobal period

What modifiers do to the payment

Modifier 50 · payment effect

With and without the modifier

27310 without 50 · national facility

$689.06

Knee arthrotomy

27310-50 · Bilateral: 150%

$1,033.59

Both sides on one line with modifier 50 are paid at 150% of the fee schedule amount (subject to multiple-procedure rules with other procedures).

When to use modifier 50

27310 compared with similar codes

Compare codes

27310 vs 27330 vs 27331 vs 29871: national Medicare rates

Swap in your local Medicare rate.

  • 27310
    Knee arthrotomy · 9.75 wRVU
    —
  • 27330
    Knee biopsy · 4.98 wRVU
    —
  • 27331
    Knee arthrotomy · 5.87 wRVU
    —
  • 29871
    Knee arthroscopy · 6.52 wRVU
    —

How to choose

27330Knee biopsy
Choose 27330 when the open knee-joint procedure is for biopsy. Choose 27310 for exploration, drainage, or foreign-body removal.
27331Knee arthrotomy
27331 represents a different open knee-joint service centered on synovectomy; 27310 is for exploration, drainage, or foreign-body removal.
29871Knee arthroscopy
29871 is the arthroscopic approach to knee treatment. 27310 describes open joint access for exploration, drainage, or foreign-body removal.

Codes related to 27310

Related codes aren’t interchangeable: bill the code that matches the service performed.

Codes related to 27310
CodeHow it relatesNational office range
Same family
27330Knee biopsyOpen knee-joint biopsy is a related arthrotomy service with a different operative purpose.No office rate
Used instead
27331Knee arthrotomyA distinct open knee-joint procedure when the operative work centers on synovectomy.No office rate
29871Knee arthroscopyArthroscopic knee treatment, rather than the open approach represented by 27310.No office rate
27301Deep drainageDrainage of a thigh or knee-area lesion outside the joint, not intra-articular drainage.$633.17–$921.54

27310 billing questions

When is 27310 a better fit than knee arthroscopy?

Use 27310 for the described open joint approach. Arthroscopic drainage or treatment uses an arthroscopy code when that method is performed.

How does 27310 differ from an open knee-joint biopsy?

27310 represents exploration, drainage, or foreign-body removal. When the operative purpose is obtaining a synovial or other joint biopsy, consider 27330 instead.

Does the 90-day global include routine postoperative care?

Yes. The global period includes the day-before preoperative visit and 90 days of related postoperative care.

Can an assistant or co-surgeon be reported?

An assistant at surgery may be paid. Co-surgeon payment requires supporting documentation; team surgery is not permitted.

How is bilateral reporting handled?

For bilateral knee procedures, modifier 50 is paid at 150% under the CMS bilateral rule for this code.

What happens when another procedure is performed in the same session?

The highest-valued procedure is paid in full, and other procedures are subject to the standard multiple-procedure reduction.

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
RVUs for 27310PPRRVU2026_Oct_nonQPP.csv, line 2,833 (RVU26D)

Open CMS sourceHow we calculate rates

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