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Billing code 31291: CSF leak repairMedicare rate & RVUs

Reports endoscopic repair of a cerebrospinal fluid leak arising in the sphenoid region, typically performed transnasally by an otolaryngologist or skull-base surgeon.

CMS RVU26DEffective Oct 1, 2026109 payment localities112 Medicare services in 2024

Medicare pays $1,076.85 for 31291 nationally in a facility.

Medicare rate · 31291

CSF leak repair

Swap in your local Medicare rate.

Work RVUs
19.07
Total RVUs
32.24
Global days
010

National rate · 2026

$1,076.85

Facility setting, before claim adjustments.

See every locality for 31291 → · 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 31291 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 31291 covers

This service repairs a cerebrospinal fluid leak in the sphenoid region through a nasal endoscope. An otolaryngologist, rhinologist, or skull-base surgeon typically identifies the leak and closes the defect, often with graft material or a tissue flap. The operation is generally performed in a hospital or ambulatory surgery setting; the operative note should establish the sphenoid site and describe the endoscopic repair rather than sinus surgery for routine inflammatory disease.

Select this code based on the location of the leak, not simply because the surgeon worked in the sphenoid sinus. The record should document the leak site, endoscopic approach, and repair performed. Related endoscopies performed during the same session are subject to endoscopy-family pricing. CMS assigns a 10-day global period, including related postoperative visits during that period. For bilateral reporting, modifier 50 is paid at 150%. Assistant-at-surgery payment requires documentation of medical necessity; co-surgeons and team surgery are 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 31291 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

31291 office and facility rates by payment locality
Payment localityOfficeFacility
AlabamaUnavailable$983.98
Alaska*Unavailable$1,360.91
ArizonaUnavailable$1,049.36
ArkansasUnavailable$972.65
AtlantaUnavailable$1,108.47
AustinUnavailable$1,082.55
BakersfieldUnavailable$1,071.48
Baltimore/Surr. CntysUnavailable$1,139.25
BeaumontUnavailable$1,039.58
BrazoriaUnavailable$1,052.12

31291 rates by state

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

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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.

View every state and territory as a table
31291 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 31291 rate is calculated

Each of 31291’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 · 31291

RVUs × geographic indexes × conversion factor

Swap in your local Medicare rate.

Work 19.07Practice expense 9.50Malpractice 3.67

32.2400 adjusted RVUs×$33.4009 conversion factor=$1,076.85

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

Payment rules and modifiers for 31291

31291 has a 10-day global period: related visits in that window are included in the surgery payment.

CMS payment indicators · 31291

CSF leak repair

RuleCMS valueWhat it means
Global period010Minor procedure: the day of the procedure plus 10 days after are included.
Multiple procedures3Endoscopy family rules apply.
Bilateral (modifier 50)1Bilateral with modifier 50 pays 150% of the fee schedule amount.
Assistant at surgery (80/81/82/AS)0Not paid without supporting documentation.
Co-surgeons (62)0Not permitted.
Team surgery (66)0Not permitted.
Professional/technical0Physician service: no professional/technical split.
Split (54/55/56)0.10/0.80/0.10Share of the payment for pre-op, the procedure itself, and post-op care.

Global surgery period · 31291

CSF leak repair

10-day global period ends

Oct 11, 2026

Covers Oct 1, 2026 through Oct 11, 2026 (11 days).

Visit on Oct 31, 2026

After the global period ends: visits and procedures are billed normally.

SurgeryVisit
Sep 28, 2026Oct 14, 2026

What modifiers do to the payment

Modifier 50 · payment effect

With and without the modifier

31291 without 50 · national facility

$1,076.85

CSF leak repair

31291-50 · Bilateral: 150%

$1,615.28

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

31291 compared with similar codes

Compare codes

31291 vs 31290 vs 31287 vs 31288: national Medicare rates

Swap in your local Medicare rate.

  • 31291
    CSF leak repair · 19.07 wRVU
    —
  • 31290
    CSF leak repair · 18.14 wRVU
    —
  • 31287
    Sphenoidotomy · 3.41 wRVU
    —
  • 31288
    Sphenoid surgery · 4 wRVU
    —

How to choose

31290CSF leak repair
Both codes describe endoscopic repair of a CSF leak, but 31290 applies to the ethmoid region; 31291 applies to the sphenoid region.
31287Sphenoidotomy
This code describes sphenoid sinusotomy without tissue removal, not repair of a CSF leak.
31288Sphenoid surgery
This code describes sphenoid sinusotomy with tissue removal. Choose 31291 when the service is repair of a sphenoid-region CSF leak.

Codes related to 31291

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

Codes related to 31291
CodeHow it relatesNational office range
Same family
31290CSF leak repairEndoscopic CSF leak repair in the ethmoid region; the repair site distinguishes it from this code.No office rate
Often billed with
31287SphenoidotomySphenoid sinusotomy may be performed in the same session; related endoscopies are subject to family pricing.No office rate
31288Sphenoid surgerySphenoid sinusotomy with tissue removal may accompany other operative work; endoscopy-family pricing can apply.No office rate

31291 billing questions

How is this distinguished from 31290?

Use 31291 when the cerebrospinal fluid leak being repaired is in the sphenoid region. Code 31290 is for a leak in the ethmoid region.

Does this code cover ordinary sphenoid sinus surgery?

No. It represents endoscopic repair of a cerebrospinal fluid leak in the sphenoid region, not routine sphenoidotomy or removal of sinus tissue.

Can another nasal or sinus endoscopy be reported in the same session?

Related endoscopies performed together are subject to CMS endoscopy-family pricing. The operative record should identify each distinct service and its site.

What documentation supports reporting this code?

Document the sphenoid location of the leak, the endoscopic approach, and the repair performed. The site helps distinguish this code from ethmoid-region leak repair.

How are bilateral procedures and assistant services handled?

CMS pays bilateral reporting with modifier 50 at 150%. Assistant-at-surgery payment requires documented medical necessity; co-surgeons and team surgery are not permitted.

What postoperative care is included?

The 10-day global period includes related postoperative visits during those 10 days.

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 31291PPRRVU2026_Oct_nonQPP.csv, line 3,546 (RVU26D)

Open CMS sourceHow we calculate rates

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