The American Medical Association tracks over 150 procedure-specific codes for obstetrics and gynecology practices. That’s a lot to manage when you’re already handling patient care. According to recent data from the American College of Obstetricians and Gynecologists, OBGYN practices see denial rates hovering between 18-22%. Most of these denials trace back to coding errors and incomplete documentation.
The 2026 CPT updates bring changes to prenatal care, postpartum care, and laparoscopic procedures. These revisions affect how you bill for routine services and surgical interventions. Understanding current OB GYN coding guidelines helps protect your revenue and keeps claims moving through the payment cycle.
This guide covers essential CPT codes for obstetrics and gynecology and OBGYN CPT codes, plus the ICD-10-CM diagnosis codes that support them. You’ll learn how to apply OBGYN coding guidelines correctly and avoid common pitfalls in OBGYN billing and coding.
OBGYN CPT Codes for Diagnostic Procedures
CPT Code 57452: Colposcopy with Biopsy
When you perform a colposcopy with an endocervical biopsy, you’ll report CPT Code 57452. This procedure helps identify cervical dysplasia and precancerous changes. Your documentation needs to capture what you saw during the colposcopy and where you took biopsies.
Most payers want to see a clear connection between the procedure and the patient’s diagnostic workup. Abnormal Pap results or positive HPV tests typically justify the medical necessity. Link your CPT code to the appropriate diagnostic codes showing why the colposcopy was needed.
CPT Code 58100: Endometrial Biopsy
Office-based endometrial biopsy gets reported with CPT Code 58100. This applies when you sample the endometrium without dilating the cervix. You’ll use this code for patients with abnormal uterine bleeding or when you need to rule out endometrial hyperplasia.
Here’s where things get tricky. If you perform a significant evaluation beyond the standard pre-procedure assessment, you can bill an E/M service with Modifier 25. But your documentation must clearly show the separate evaluation. Payers audit this modifier combination heavily, so make sure your notes justify both services.
CPT Code 76830: Transvaginal Ultrasound
CPT Code 76830 covers transvaginal ultrasound of the uterus, ovaries, and surrounding structures. This imaging provides better detail than transabdominal techniques for gynecologic issues. Don’t confuse this with obstetric pelvic ultrasound codes (76801-76828), which apply specifically to pregnancy-related imaging.
Document which structures you examined and what you found. Your medical necessity should be clear from the clinical indication. OBGYN billing services can help ensure you’re selecting the right ultrasound code based on whether the patient is pregnant.
OBGYN CPT Codes for Surgical Procedures
Surgical CPT codes for obstetrics and gynecology require precise documentation to support medical necessity and surgical approach selection. Mastering these OBGYN CPT codes ensures accurate claim submission and optimal reimbursement.
CPT Code 58150: Abdominal Hysterectomy
Total abdominal hysterectomy through an abdominal incision gets coded as 58150. This removes both the uterus and cervix. Your operative note should specify the surgical approach and document any additional structures removed.
If you also perform bilateral salpingo-oophorectomy during the same surgery, report that separately with Modifier 51. CMS looks at surgical approach and specimen weight when determining the correct code, so include these details in your documentation.
CPT Code 58570: Laparoscopic Hysterectomy
For laparoscopic procedures, CPT Code 58570 applies when the uterus weighs 250 grams or less. This minimally invasive approach requires detailed documentation of your trocar sites and how you removed the specimen. Whether you removed it vaginally or used morcellation affects the supporting documentation you’ll need.
Sometimes you need to switch from laparoscopic to open surgery. Document why this occurred and adjust your coding accordingly. Medical billing services assist you in matching your operative reports to the appropriate surgical codes.
CPT Code 58700: Salpingectomy
Salpingectomy is reported using CPT Code 58700. This includes the removal of one or both fallopian tubes. Document whether the procedure was unilateral or bilateral, and explain the clinical reasoning.
More practices are now performing prophylactic bilateral salpingectomy to reduce the risk of ovarian cancer. Medicare coverage varies by region, so check your benefits ahead of time. Your documentation should include genetic test results or a family history that supports the medical need.
CPT Code 58956: Radical Surgical Procedure
CPT Code 58956 refers to complex cancer surgeries that include bilateral salpingo-oophorectomy and omentectomy. These procedures necessitate extensive documentation demonstrating the extent of resection and any staging work performed during surgery. This code differs from simpler procedures due to the cancer diagnosis and surgical complexity.
OBGYN CPT Codes for Infertility Procedure
CPT Code 58970: Oocyte Retrieval
During IVF cycles, CPT Code 58970 is used for transvaginal oocyte retrievals. Record the number of follicles aspirated and the number of oocytes retrieved. Most commercial insurers require pre-authorization for infertility treatments.
Coverage limits frequently limit the number of retrieval cycles that they will reimburse. Check the patient’s benefits before proceeding, and obtain any necessary authorizations.
CPT Code 58974: Embryo Transfer
CPT Code 58974 indicates embryo transfer into the uterus following in vitro culture. Your documentation should include the number of embryos transferred and the catheter technique you used. Many payers now limit embryo numbers based on the patient’s age and previous cycle results.
CPT Code 58976: Gamete Transfer
Gamete intrafallopian transfer requires laparoscopic access to the fallopian tubes. Report this with CPT Code 58976. You’ll need documentation confirming tubal patency before the procedure. Coverage for GIFT procedures varies widely, so verify benefits and get pre-authorization when required.
OB GYN CPT Codes for Contraceptive Services
CPT Code 58300: IUD Insertion
CPT Code 58300 is for intrauterine device insertion. Document the device type (hormonal or copper) and ensure proper placement. Medicare and Medicaid typically cover IUD insertion as a preventive measure.
Remember that procedural reimbursement and device supply costs are billed separately. To maximize your reimbursement, ensure that you handle both components correctly.
CPT Code 58301: IUD Removal
Simple IUD removal is coded as 58301. If the removal proves difficult and necessitates the use of specialized instrumentation or imaging, record the technical details. Some payers include simple removals in E/M services; therefore, check individual payer policies.
OBGYN CPT Codes for Reproductive Health
CPT Code 59812: Suction D&C for Incomplete Abortion
The suction D&C CPT code for incomplete abortion is 59812. This suction D&C CPT code specifically addresses the treatment of pregnancy loss through uterine evacuation, not elective termination.
This code specifically addresses the treatment of pregnancy loss, not elective termination. CMS wants to see documentation of the medical indication and why expectant management wasn’t appropriate.
CPT Code 59840: Induced Abortion
CPT Code 59840 applies to induced abortion through cervical dilation and evacuation. This typically covers first-trimester procedures. Coverage varies dramatically based on state laws and insurance plan exclusions.
It is important to clearly differentiate between elective abortion procedures and medically indicated abortion procedures, as each payer will treat these two categories of care differently.
ICD-10-CM Diagnosis Code Tables for OBGYN Procedures
Essential Obstetric ICD-10-CM Codes
| ICD-10-CM Family | Clinical Description | When to Use | Key Documentation Elements | Common CPT Pairings |
| Z34.- | Supervision of normal pregnancy | Routine prenatal visits without complications | · Trimester (1st, 2nd, 3rd) · Gravida/Para status · Normal fetal development | 59400, 59510, 59610, 59618 (global packages) |
| O09.- | Supervision of high-risk pregnancy | Advanced maternal age (≥35), prior preterm birth, poor obstetric history | · Specific risk factor · Trimester · Management plan adjustments | Enhanced prenatal visits, additional ultrasounds, NST |
| Z3A.xx | Weeks of gestation | Nearly all pregnancy encounters requiring gestational age | · Exact week (00-42) · Calculated from LMP or dating ultrasound | All prenatal and delivery codes |
| O00.- | Ectopic pregnancy | Pregnancy implanted outside uterus | · Site (tubal, ovarian, abdominal) · With/without complications · Beta-HCG levels | 59120, 59121, 59150, 59151 |
| O02.- | Abnormal products of conception | Blighted ovum, missed abortion, molar pregnancy | · Type of abnormality · Ultrasound findings · Beta-HCG trends | 59812, 59820, 59830 |
| O03.- | Spontaneous abortion | Miscarriage with/without intervention | · Complete vs. incomplete · With/without complications · Weeks’ gestation | 59812 (if D&C performed), E/M only if expectant management |
| O20.- | Hemorrhage in early pregnancy | First-trimester bleeding, threatened abortion | · Amount of bleeding · Maternal stability · Fetal viability status | Ultrasound (76817), E/M with Modifier 25 |
| O21.- | Hyperemesis gravidarum | Severe nausea/vomiting in pregnancy | · Weight loss percentage · Ketones present · Dehydration status IV hydration given | E/M, IV hydration (96360-96361), anti-emetics |
| O24.- | Diabetes in pregnancy | Preexisting Type 1/2 or gestational diabetes | · Type (preexisting vs. GDM) · Diet-controlled vs. insulin-dependent · A1C values | NST (59025), BPP (76818-76819), enhanced ultrasounds |
| O10–O16 | Hypertensive disorders | Chronic HTN, gestational HTN, preeclampsia | · Type and severity · BP readings · Lab values (protein, liver, platelets) | NST, BPP, delivery planning, antepartum admits |
| O30.- | Multiple gestation | Twins, triplets, or higher multiples | · Number of fetuses · Chronicity · Fetus-specific 7th character | Multiple gestation ultrasounds, enhanced monitoring |
| O32.- | Malpresentation | Breech, transverse, oblique lie | · Type of malpresentation · Fetus number (if multiples) · ECV attempted/declined | 59412 (external cephalic version), delivery planning |
| O34.- | Maternal care for abnormalities | Uterine scar, fibroids, cervical insufficiency | · Type of abnormality · Prior surgeries · Impact on delivery planning | 59320-59325 (cerclage), cesarean delivery codes |
| O36.- | Fetal problems | Growth restriction, fetal demise, isoimmunization | · Specific fetal condition · Fetus number · Monitoring frequency | Growth ultrasounds, Doppler studies, NST, BPP |
| O42.- | Premature rupture of membranes | PROM or PPROM | · Timing (hours since rupture) · Weeks’ gestation · Complications | Steroids, antibiotics, delivery planning, 59430 (after delivery care) |
| O44.- | Placenta previa | Placenta covering or near the cervix | · Type (complete, partial, marginal) · Bleeding episodes · Ultrasound confirmation | Ultrasounds, cesarean delivery (59510, 59618) |
| O99.- | Other maternal diseases | Anemia, thyroid, obesity, substance use | · Underlying condition · Impact on pregnancy · Treatment modifications | Additional monitoring, specialty consults, E/M |
| Z37.- | Outcome of delivery | Documentation of delivery result | · Single/multiple birth · Liveborn vs. stillborn · Birth weight | All delivery codes (59400, 59510, 59610, 59618, 59620) |
| Z39.- | Postpartum care | Routine postpartum follow-up | · Weeks postpartum · Issues addressed · Contraception counseling | E/M (99213-99214), included in global if within 6 weeks |
Essential Gynecologic ICD-10-CM Codes
| ICD-10-CM Family | Clinical Description | When to Use | Key Documentation Elements | Common CPT Pairings |
| N80.- | Endometriosis | Laparoscopic confirmation or strong clinical suspicion | · Site (ovary, peritoneum, bowel, etc.) · Laterality · Severity/stage | 58662, 58670-58679 (laparoscopy), chronic pain management |
| D25.- | Uterine leiomyoma (fibroids) | Symptomatic fibroids causing bleeding, pain, and pressure | · Number and location · Size (largest diameter) · Symptoms attributed | 58140-58146 (myomectomy), 58150-58294 (hysterectomy), 76830 (ultrasound) |
| N84.- | Polyp of the female genital tract | Endometrial, cervical, or vaginal polyp | · Location · Size · Symptomatic vs . incidental | 58100 (EMB), 58558 (hysteroscopy with polypectomy), 57500 (cervical) |
| N92.- | Excessive/frequent/irregular menstruation | Heavy menstrual bleeding (menorrhagia) | · Cycle pattern· Duration (days) · Soaking pattern · Hemoglobin is anemic | 58100 (EMB), 58353 (endometrial ablation), 76830 (ultrasound) |
| N93.- | Other abnormal uterine bleeding | Intermenstrual, postcoital bleeding | · Timing relative to the cycle · Triggers · Pregnancy ruled out | 57452 (colposcopy), 58100 (EMB), 58558 (hysteroscopy) |
| N94.6 | Dysmenorrhea | Painful menstruation | · Primary vs. secondary · Severity impact on function · Response to NSAIDs | E/M, laparoscopy if severe/unresponsive |
| N83.2- | Ovarian cyst | Functional, corpus luteum, or other cyst | · Side (right/left) · Size (cm) · Simple vs Complex · Resolution timeline | 76830 (ultrasound), 58661 (laparoscopy), 49322 (aspiration) |
| N70.- | Salpingitis and oophoritis (PID) | Pelvic inflammatory disease | · Acute vs. chronic· Clinical criteria met· Cultures obtained | E/M with antibiotics, possible admit |
| N76.- | Vaginitis/vulvovaginitis | Bacterial vaginosis, candidiasis, trichomoniasis | · Organism identified (or “unspecified”) · Symptoms · Risk factors | E/M, wet mount, pH testing, treatment |
| N87.- | Dysplasia of cervix uteri (CIN) | Cervical intraepithelial neoplasia | · Grade (CIN 1, 2, 3) · Biopsy confirmation · Margins if excised | 57452-57461 (colposcopy), 57510-57522 (LEEP/CKC) |
| D06.- | Carcinoma in situ of cervix | CIS confirmed on pathology | · Histologic type · Margin status · Treatment plan | 57520 (conization), 57522 (loop electrode conization) |
| R87.61- | Abnormal cervical cytology | ASC-US, ASC-H, LSIL, HSIL, AGC | · Exact cytology result · HPV status · Follow-up plan | 57452 (colposcopy), HPV testing, repeat Pap |
| N88.- | Other noninflammatory cervical disorders | Cervical stenosis, ectropion, incompetence | · Type of disorder · Symptoms · Prior procedures | 57800 (dilation), cervical repair codes |
| N89.-/N90.- | Disorders of the vagina/vulva | Atrophic vaginitis, vulvar dystrophy, lesions | · Site and extent · Symptoms · Biopsy results, if obtained | 56605-56606 (biopsy), topical estrogen, E/M |
| N39.3 | Stress urinary incontinence | Leakage with cough, sneeze, and exertion | · Provocative maneuvers · Pad use · Previous treatments | Urodynamics, pelvic floor PT, 57288 (sling) |
| N32.81 | Overactive bladder | Urgency, frequency, nocturia ± urge incontinence | · Bladder diary · Failed conservative measures · Quality of life impact | Urodynamics, medications, Botox, PTNS |
| Z30.- | Encounter for contraceptive management | Counseling, device insertion/removal, prescription | · Method discussed/provided · Risks/benefits counseled · Patient choice | 58300 (IUD insertion), 58301 (removal), 11981 (implant insertion) |
| Z01.411/.419 | Gynecological exam | Annual well-woman visits | · With/without abnormal findings · Screening performed · Counseling provided | 99384-99387 (preventive E/M), screening Pap/HPV |
| Z12.4 | Cervical cancer screening | Screening Pap/HPV test | · Screening intent · No symptoms · Age-appropriate interval | 88142-88175 (Pap), 87624-87625 (HPV) |
Essential Modifiers for OBGYN Billing
Modifier 25: Separate E/M Services
Modifier 25 tells payers you performed a significant, separately identifiable evaluation on the same day as a procedure. Your documentation must show that this service was beyond the standard pre-operative E/M assessment, and payers will definitely perform a thorough audit of this modifier and require solid documentation supporting separate E/M and procedural services.
Modifier 51: Multiple Procedures
Modifier 51 applies to secondary procedures performed during the same surgery. Add this modifier to any procedure that’s not your primary one (the procedure with the highest RVU). This tells the payer to apply NCCI payment reductions—which they’ll do automatically if you code it right.
Modifier 57: Decision for Surgery
Modifier 57 tells payers that your E/M service on the day of (or day before) a major procedure was the visit where you decided the patient needed surgery. This isn’t the routine pre-op check; it’s the evaluation that led to scheduling the surgery in the first place. Document what findings prompted your surgical decision.
Proper modifier application represents a critical component of OB GYN billing and coding. Understanding how to apply these modifiers to OB GYN CPT codes reduces denial risk and supports accurate reimbursement for separately identifiable services.
Maximizing Medicare Reimbursement
Demonstrate Medical Necessity
Medicare bases coverage on Local Coverage Determination policies. Each procedure code needs appropriate ICD-10-CM diagnosis codes supporting why the service was necessary. Show failed conservative treatments when relevant. This strengthens your case for authorization.
Following current OB GYN coding guidelines when linking diagnosis codes to CPT codes for obstetrics and gynecology establishes clear medical necessity. Proper application of OBGYN coding principles supports authorization requests and withstands payer audits.
Focus on Documentation Completeness
Operative notes must contain all items related to the surgical procedure, including surgical technique, findings, complications, and specimen details. In addition to these items, the CMS auditor must review the specifics of the surgical approach and laterality. Credentialing Services assist with meeting the documentation requirements of the payer(s).
Understand Payer Policies
Medicare Administrative Contractors (MAC) provide the coverage criteria based on local jurisdiction. Commercial payers have their own policies and reimbursement processes that may differ from those provided by MACs. Practicing in multiple states can result in variations of rules, regulations, and processes.
Common Claim Denial Reasons for OBGYN CPT Codes
OBGYN claims get denied for predictable reasons. Here’s what trips up most practices:
- Missing medical necessity – Your documentation doesn’t explain why you performed the procedure. Link your diagnosis codes to clinical findings that justify the service.
- Bundling errors – You billed separately for something that’s included in a comprehensive code. NCCI edits catch these automatically and deny the claim.
- Modifier mistakes – Wrong modifier or missing modifier when you needed one (especially Modifier 25 and 51).
- Authorization gaps – You didn’t get pre-auth for procedures that require it, or the authorization expired before the surgery.
- Global period violations – You billed for a service that’s included in the surgical package (like routine post-op visits within 90 days).
- Incomplete operative reports – Missing details about surgical approach, findings, or specimen weight, delaying processing,g and triggering documentation requests.
- Late filing – You missed the payer’s deadline (which varies—some allow 90 days, others require filing within 30).
Most denials are fixable if you catch them within 48-72 hours. Track your denial patterns monthly to spot systematic issues before they cost you thousands. Understanding these denial patterns helps practices refine their OB GYN billing and coding processes. Regular audits of OB GYN CPT codes identify systematic errors before they impact revenue.
Implementing accurate OB GYN coding guidelines reduces claim rejections and accelerates payment cycles. Practices specializing in CPT codes for obstetrics and gynecology benefit from continuous education on payer-specific requirements and documentation standards.
CPT Code Comparisons: OBGYN Procedures
Hysterectomy Code Selection: 58150 vs. 58570
CPT code 58150 reports an abdominal approach requiring a greater incision with longer recovery times than the laparoscopic procedure (58570). It is necessary to choose the correct code according to the surgical approach, how the surgeon visualized the uterus, and how the surgeon removed the specimen.
The choice between abdominal (58150) and laparoscopic (58570) hysterectomy depends on clinical factors: uterine size, presence of adhesions, planned concurrent procedures, and surgeon skill level. Document why you chose the laparoscopic approach. Payers want to see that it was clinically appropriate, not just a preference
Endometrial Sampling: 58100 vs. 59812
CPT Code 58100 designates an office-based endometrial biopsy for diagnostic purposes, while 59812 reports dilation and curettage for treatment of incomplete abortion. The key difference: 58100 is diagnostic (office biopsy), while 59812 treats pregnancy loss (requires cervical dilation and anesthesia).
Simple endometrial sampling inherently requires very little anesthesia, allowing for a much shorter recovery time than D&C procedures, which will require cervical dilation (the opening of the cervix) and the removal of the entire uterus.
Reimbursement policies for payers vary widely; therefore, there is a greater incidence of reimbursement for diagnostic biopsies since they may be covered under plan benefits, while abortion procedures generally have significant exclusions or are governed by certain regulations within a particular state.
IUD Services: 58300 vs. 58301
CPT Code 58300 reports IUD insertion, including device cost considerations, while 58301 designates removal-only services. Practices need to differentiate between billing for the IUD and billing for the services provided in conjunction with the IUD.
When billing to Medicare and Medicaid for IUD insertion, there is full preventive coverage. However, Medicare and Medicaid may not cover the removal of an IUD unless there is some type of medical necessity. Coverage for the routine removal of an IUD varies from commercial payer to commercial payer.
Conclusion
Accurate OB GYN billing and coding requires strong documentation habits, proper modifier use, and staying current with payer policies. The complexity of OBGYN coding and the breadth of OB GYN CPT codes mean your clinical and administrative teams need to work closely together. Continuous education on OBGYN CPT codes and OBGYN coding best practices protects revenue and reduces administrative burden.
Nexus io specializes in OBGYN billing services, combining certified coders with AI-powered claim review. We handle charge entry services, denial management, and real-time eligibility checks for OBGYN practices. Our team helps reduce denials and maximize your revenue through expert coding support. Contact us to see how we can improve your billing performance.
