Copy-pasting an old SuperCoder article but relevant in the context of the question:-
Published in Ob-Gyn Coding Alert, May 2004
Experts advise how to ethically get the most for twin pregnancy services
You may not code for multiple-gestation services every day, but don’t let your skills get rusty. If you’re not capturing all the associated services, your practice’s bottom line could suffer.
Our experts answer the five most frequently asked questions regarding multiple- gestation care and delivery:
1. How Should I Report Twin Delivery?
If your patient is having twins, most ob-gyns first attempt a vaginal delivery as long as the physician hasn’t identified any complications. In this case, you should report 59400 (Routine obstetric care including antepartum care, vaginal delivery [with or without episiotomy, and/or forceps] and postpartum care) for the first baby and 59409-51 (Vaginal delivery only [with or without episiotomy and/or forceps]; multiple procedures) for the second.
“I have also appended modifier -22 (Unusual procedural services) to the global delivery (59400) if the patient has had more than the average 13 visits,” says Brenda Dombkowski, CPC, a coding specialist at Obstetric-Gynecology & Infertility Group in Cheshire, Conn. “Check with your payer because this may vary with each of them.”
Best bet: Send a letter of explanation with the claim to avoid immediate denial by the claim processor, says Cheryl A. Lewis, CPC, billing manager for ZIA Ob-Gyn Ltd. in Yuma, Ariz. “A simple form letter explaining the high-risk nature of multiple-gestation pregnancies will routinely go straight to medical review and save the hassle of denial resubmissions or lost reimbursement through write-offs.”
If the physician delivers the first baby vaginally but the second via cesarean, assuming he provided global care, report 59510 (Routine obstetric care including antepartum care, cesarean delivery, and postpartum care) for the second baby and 59409-51 for the first, says Peggy Stilley, CPC, office manager for Women’s Healthcare Specialists, an Oklahoma University-based private ob-gyn practice in Tulsa. You should include 651.01 (Twin pregnancy; delivered, with or without mention of antepartum condition) and V27.2 (Twins, both liveborn) as diagnoses, she adds.
For the second twin born by cesarean, use additional ICD-9 codes to explain why the ob-gyn had to perform the c-section — for example, malpresentation (652.6x, Multiple gestation with malpresentation of one fetus or more) — and the outcome (such as V27.2, Twins, both liveborn), Stilley points out.
Multiple via c-section: When the doctor delivers all of the babies, whether twins, triplets, etc., by cesarean, you should submit 59510 with modifier -22 appended. Because the ob-gyn made only one incision, he performed only one cesarean, but the modifier shows that the physician performed a significantly more difficult delivery due to the presence of multiple babies. Be sure to include a letter with the claim that outlines the additional work that the ob-gyn performed to give the carrier a clear picture of why you’re asking for additional reimbursement.
2. What if They Come on Different Days?
Occasionally, multiple-gestation babies will be born on different days. For example, a patient is at 38 weeks gestation and carrying twins in two sacs. One membrane ruptures, and the ob-gyn delivers the baby vaginally. Two days later, the second ruptures, and the second baby delivers vaginally as well.
Here, you should report the first baby as a delivery only (59409) on that date of service, Stilley says. For the second, you should bill the global code (59400), assuming the physician provided prenatal care, on that date of service, she adds. “The reason not to bill the global first is that you are still offering prenatal care due to the retained twin.
“I promise that you will have to attach a letter explaining the situation to the insurance company,” Stilley points out. “ICD-9 will be important to the payment. Be sure to use the outcome codes” (for example, V27.2).
3. What About All Those Ultrasounds?
Invariably, multiple-gestation pregnancies mean multiple ultrasounds. Generally, ob-gyns use obstetric ultrasounds to show viability, the number of fetuses, fetal position, amniotic fluid volume, fetal measurements, placental location, and fetal weight estimation and allow basic anatomical review. In this case, you must choose the codes based on fetal age:
76801 — Ultrasound, pregnant uterus, real time with image documentation, fetal and maternal evaluation, first trimester (<14 weeks 0 days), transabdominal approach; single or first gestation
+76802 — … each additional gestation (list separately in addition to code for primary procedure)
76805 – Ultrasound, pregnant uterus, real time with image documentation, fetal and maternal evaluation, after first trimester (> or =14 weeks 0 days),
transabdominal approach; single or first gestation
+76810 – … each additional gestation (list separately in addition to code for primary procedure).
For example: If the physician orders an ultrasound in gestation week 12 to confirm the presence of triplets, you would report 76801, 76802 and 76802. For each subsequent ultrasound, you normally should use 76816 (Ultrasound, pregnant uterus, real time with image documentation, follow-up [e.g., re-evaluation of fetal size by measuring standard growth parameters and amniotic fluid volume, re-evaluation of organ system(s) suspected or confirmed to be abnormal on a previous scan], transabdominal approach, per fetus). “Report 76816 with modifier ‘-59′ (Distinct procedural service) for each additional fetus examined in a multiple pregnancy,” according to CPT. For example with triplets, you would use 76816, 76816-59 and 76816-59, Stilley says.
On the other hand, if you perform all the elements associated with a more complex ultrasound code — such as a detailed fetal anatomic examination in addition to a full fetal and maternal evaluation — because of high risk or other factors, you should report those codes. In this case, for a multiple gestation you would use 76811 (Ultrasound, pregnant uterus, real time with image documentation, fetal and maternal evaluation plus detailed fetal anatomic examination, transabdominal approach; single or first gestation) for the first fetus and +76812 (… each additional gestation [list separately in addition to code for primary procedure]) for each additional fetus.
“Codes 76811 and 76812 may require more sophisticated equipment and the expertise of a maternal-fetal medicine physician,” Dombkowski notes. “Office-level equipment may not be able to obtain the necessary detailed imaging.”
Transvaginal ultrasound: Occasionally, the ob-gyn will use a transvaginal ultrasound when he evaluates a multiple-gestation patient. In this case, you should report 76817 (Ultrasound, pregnant uterus, real time with image documentation, transvaginal) only once, according to the American College of Obstetricians and Gynecologists. You can try adding modifier -22 if the documentation indicates significant additional physician work. But ob-gyns normally don’t use the transvaginal scan for an extensive examination of the fetus(es).
“Remember, all obstetrical ultrasounds are transabdominal except 76817, and it may be necessary to do a transvaginal in addition to a transabdominal,” Dombkowski says. If the ob-gyn performs both types of ultrasounds during the same visit, you can report both by appending modifier -59 to 76817. But keep in mind, “you must have separate reports for both approaches with corresponding ICD-9 codes that show the medical necessity to perform both approaches,” she warns.
4. We Did NSTs and BPPs. What Now?
Ob-gyns commonly use fetal non-stress tests (NSTs, 59025, Fetal non-stress test) and biophysical profiles (BPPs, 76818, Fetal biophysical profile; with non-stress testing; or 76819, … without non-stress testing) with multiple-gestation pregnancies. You should report 76818 or 76819 for the first fetal BPP, depending on whether the physician also performed the NST. “Fetal biophysical profile assessments for the second and any additional fetuses should be reported separately by code 76818 or 76819 with the modifier -59 appended,” according to CPT.
“I have billed NSTs both with modifier -59 and with two units with positive results,” Dombkowski says.
NSTs are just like BPPs: Although CPT does not tell you how to bill a multiple-gestation NST, you can extend the BPP coding instruction to use modifier -59 for such NSTs, coding experts say. Alternatively, you could use modifier -22 to indicate the additional work or modifier -51 for multiple procedures. Consequently, you should contact your payer to determine which coding method it prefers.
5. What Should I Do About Amniocentesis?
If your ob-gyn performs amniocentesis for a patient carrying twins, triplets, etc., the coding depends on how many needle sticks he performs. If the physician sticks the patient only once to obtain amniotic fluid, you should report 59000 (Amniocentesis; diagnostic) only once. On the other hand, if he draws samples with multiple needle sticks (for example, from each amniotic sac), you should submit additional units of 59000 on separate line items for each stick. You also should append modifier -59 to the second and subsequent amnio codes.