Billing code 31020: Maxillary sinusotomyMedicare rate & RVUs in Guam
Reports surgical opening of a maxillary sinus through the nasal cavity when treatment requires more than irrigation or a different surgical approach.
Medicare pays $470.46 for 31020 in the office in Guam (Hawaii, Guam). Which amount applies depends on the service address.
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 9 sections
What 31020 covers
billing code 31020 represents surgical access to a maxillary sinus through the nasal cavity to open or enlarge its drainage pathway. An otolaryngologist typically performs the procedure for maxillary sinus disease requiring operative drainage or access, rather than a simple sinus rinse. The code identifies the intranasal approach; it is distinct from a Caldwell-Luc operation and from endoscopic maxillary procedures reported with endoscopy-specific codes.
Select the code when the operative report supports an intranasal maxillary sinusotomy. Document the side, approach, operative work, and relevant findings so the service can be distinguished from irrigation, a different approach, or removal of a polyp. CMS assigns a 90-day global period, including the day-before preoperative visit and 90 days of related postoperative care. For multiple procedures in the same session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% reduction. Modifier 50 identifies bilateral surgery and is paid at 150%. Assistant-at-surgery payment is restricted; 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.
31020 in Hawaii, Guam
| Payment locality | Office | Facility |
|---|---|---|
| Hawaii, Guam | $470.46 | $351.22 |
How the 31020 rate is calculated
Each of 31020’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 · 31020
RVUs × geographic indexes × conversion factor
Work2.99
2.99 RVUs× 1.000 GPCI
Practice expense9.57
9.57 RVUs× 1.000 GPCI
Malpractice0.37
0.37 RVUs× 1.000 GPCI
Adjusted RVUs
12.9300
Conversion factor
$33.4009
Medicare rate
$431.87
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 31020
31020 has a 90-day global period: related visits in that window are included in the surgery payment.
CMS payment indicators · 31020
Maxillary sinusotomy
| Rule | CMS value | What it means |
|---|---|---|
| Global period | 090 | Major surgery: the day before, the day of, and 90 days after are included. |
| Multiple procedures | 2 | Standard reduction: highest-valued procedure at 100%, others at 50%. |
| Bilateral (modifier 50) | 1 | Bilateral with modifier 50 pays 150% of the fee schedule amount. |
| Assistant at surgery (80/81/82/AS) | 1 | Not paid (statutory restriction). |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 0 | Physician service: no professional/technical split. |
| Split (54/55/56) | 0.10/0.76/0.14 | Share of the payment for pre-op, the procedure itself, and post-op care. |
Global surgery period · 31020
Maxillary sinusotomy
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.
Pre-op dayGlobal period
What modifiers do to the payment
Modifier 50 · payment effect
With and without the modifier
31020 without 50 · national office
$431.87
Maxillary sinusotomy
31020-50 · Bilateral: 150%
$647.81
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).
31020 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 31000Sinus irrigation
- 31000 is maxillary sinus irrigation. Choose 31020 when the surgeon creates or enlarges a surgical opening through the nasal cavity.
- 31030Sinus exploration
- Both address the maxillary sinus, but 31030 uses a Caldwell-Luc approach. Code 31020 describes the intranasal approach.
- 31256Maxillary antrostomy
- 31256 is for endoscopic maxillary antrostomy. Use 31020 for the intranasal sinusotomy when the documented procedure is not reported as an endoscopic antrostomy.
31020 billing questions
How is 31020 different from 31030?
31020 describes access through the nasal cavity. 31030 is the maxillary sinus procedure performed through a Caldwell-Luc approach.
When should 31020 be used instead of 31000?
Use 31020 for surgical opening of the maxillary sinus. Code 31000 describes irrigation, not creation of a surgical opening.
How does 31020 differ from endoscopic maxillary antrostomy?
31020 identifies an intranasal sinusotomy. When the surgeon performs the maxillary antrostomy using nasal endoscopy, consider the endoscopic code that matches the work, such as 31256 or 31267 when tissue is removed.
How is bilateral 31020 reported?
For bilateral surgery, report modifier 50 under the CMS bilateral rule; payment is at 150%.
Can an assistant surgeon or co-surgeon be paid for 31020?
CMS restricts assistant-at-surgery payment for this code. Co-surgeons and team surgery are not permitted.
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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