Myomectomy CPT Codes: Open, Laparoscopic, Robotic and Hysteroscopic (58140–58561)

Myomectomy — removal of uterine fibroids while preserving the uterus — is one of the more nuanced gynecologic surgery coding decisions. The correct code depends on three things: the approach, the number of intramural fibroids, and their total weight. Get any of them wrong and the claim is either undercoded or unsupported.

Myomectomy CPT codes at a glance

A few points in those descriptors trip people up:

• "Intramural" drives the count and weight. The thresholds apply to intramural fibroids. Surface (subserosal or pedunculated) myomas alone fall under the lower-level code.
• "And/or" means either condition qualifies for the higher code. Five small intramural fibroids qualify for 58146/58546, and so does a single intramural fibroid weighing 300 g.
• Weight is total weight of intramural myomas removed, documented in the pathology report.

Robotic myomectomy

Robotic assistance doesn't change the code. A robotic-assisted laparoscopic myomectomy is 58545 or 58546. Some commercial payers accept HCPCS S2900 as an informational add-on for robotic assistance; Medicare doesn't recognize it. For more on how robotic cases are coded, see our guide to the CPT code for robotic hysterectomy.

Hysteroscopic myomectomy

Submucosal fibroids removed through the hysteroscope are reported with 58561, regardless of the number or the device used (resectoscope, morcellator, etc.). If an endometrial ablation is also performed, review NCCI edits and documentation carefully before reporting 58563 in addition. Diagnostic hysteroscopy (58555) is included in surgical hysteroscopy.

Choosing between 58545 and 58546: a worked example

Scenario: A robotic laparoscopic myomectomy removes three intramural fibroids and one pedunculated subserosal fibroid. Pathology reports a combined specimen weight of 310 g, with the intramural fibroids making up 280 g of that.

Coding: The three intramural fibroids number fewer than five, but their total weight exceeds 250 g, so the higher code applies: 58546.

What if pathology reports only a combined weight? Then the documentation may not clearly support that the intramural myomas exceeded 250 g. Ask the surgeon to document the number, location and approximate size of each fibroid in the operative note, and work with pathology so specimen weights are reported in a way that supports coding.

Related fibroid procedures

Adenomyomectomy

Adenomyosis isn't a leiomyoma, so the myomectomy descriptors don't technically describe excision of an adenomyoma. There's no specific CPT code for adenomyomectomy. It's generally reported with the unlisted code for the approach — 58578 laparoscopic, or 58999 open — with:

• A cover letter describing the procedure
• A comparison code with similar work (often a myomectomy code) to help the payer price it
• The operative note and pathology report

Some payers instruct practices to use a myomectomy code; follow written payer guidance if it exists. Expect these claims to need manual review, and consider prior authorization.

Diagnosis coding for fibroids

Code all fibroid locations documented, and include the symptoms or consequences the procedure addresses. Fibroids treated as part of infertility care may be subject to fertility benefit limitations — see infertility & REI billing.

Bundling and modifiers

• Diagnostic laparoscopy (49320) and diagnostic hysteroscopy (58555) are included in surgical procedures by the same approach.
• Lysis of adhesions (58660) is generally bundled; substantial extra work may support modifier 22 on the myomectomy with documentation.
• Hysteroscopic and laparoscopic myomectomy in the same session — removing submucosal fibroids hysteroscopically and intramural fibroids laparoscopically — may be separately reportable with an appropriate modifier if NCCI edits allow and the documentation clearly separates the procedures.
• Chromopertubation for tubal patency during fertility-preserving surgery is commonly bundled; check edits before reporting separately.

Prior authorization

Many payers require authorization for myomectomy, especially open and laparoscopic procedures. Make sure the authorization covers the code you're likely to bill. If you expect a large fibroid burden, request authorization for the higher-level code (58546 or 58146) or for both possibilities, according to payer rules. Changes discovered intraoperatively may need an authorization update within the payer's window. Our eligibility verification team handles this for clients.

Documentation checklist for surgeons

• Approach, including conversion (for example, laparoscopic converted to open)
• Number of fibroids removed and the location of each (intramural, subserosal, submucosal, pedunculated)
• Approximate size of each, and total weight from pathology
• Whether the endometrial cavity was entered
• Morcellation method, if used
• Any additional procedures with their indications

Common myomectomy coding errors

1. Using the higher code based on total specimen weight that includes non-intramural fibroids
2. Billing 58140/58146 for a laparoscopic or robotic case
3. Coding the lower-level code because the claim was billed before pathology
4. Reporting 49320 or 58555 separately
5. Using a myomectomy code for adenomyomectomy without payer guidance

Myomectomy during pregnancy or at cesarean

Fibroids complicate some pregnancies, and occasionally a surgeon removes a fibroid during a cesarean delivery. Coding depends on payer policy and NCCI edits: some payers allow the myomectomy to be reported in addition to the cesarean (with an appropriate modifier) when it's medically necessary and documented as a distinct procedure; others consider it incidental. The diagnosis on the delivery claim should reflect the fibroid's effect on the pregnancy — for example a code from O34.1- (maternal care for benign tumor of corpus uteri) — and the operative note should explain why removal was necessary. Expect these claims to need documentation and possibly an appeal.

Fertility-sparing surgery and benefits

Many myomectomy patients are planning future pregnancies. When fibroids are removed as part of an infertility evaluation or treatment, the payer may apply fertility benefit limits or exclusions — even though myomectomy for symptomatic fibroids is usually covered. Diagnosis selection matters: code the symptoms and fibroid locations that drove the surgery, and add infertility codes only when they reflect the documented indication.

Want a second look at your surgical coding?

Myomectomy and hysterectomy claims are high-value and documentation-dependent. Our GYN surgery coding team codes every case from the operative note and pathology report. For a quick reference of related codes, see the OB/GYN CPT code library, or message us on WhatsApp for a free review of your recent surgical claims.