Revenue Cycle Insider

Find out how to report unlisted codes for reimbursement.

Bariatric surgery, also known as weight loss surgery, is a procedure performed on patients who are obese or severely overweight. These patients may have attempted to lose weight through diet and exercise and could have health problems due to their weight. Healthcare providers can reduce the size of the patient’s stomach or alter how the small intestine absorbs food to help patients lose weight.

Read on to learn about common laparoscopic bariatric surgical procedures and how to code them.

Why Do Surgeons Use the Laparoscopic Approach?

Gastroenterology surgeons use the laparoscopic approach to bariatric surgery for three primary reasons:

1. Less invasive: A laparoscopic approach requires only a few small incisions (cuts) instead of a large abdominal incision. As a result, the patient can experience less pain, less scarring, and a shorter recovery time.
2. Decreased risk of complications: Open abdominal surgery covers a large area of the body and the exposed area can be susceptible to infections. The less invasive laparoscopic approach lowers the risk of infections, reduces bleeding, and decreases the risk of other complications.
3. Quicker recovery: The smaller incisions don’t require as much healing time as a larger incision. This allows the patient to return to their normal lives faster than patients who have open surgery.

Common laparoscopic surgeries include sleeve gastrectomy, Roux-en-Y gastric bypass, biliopancreatic diversion with duodenal switch (BPD-DS), and single anastomosis duodeno-ileal bypass (SADI).

Examine the Gastric Sleeve Procedure

A sleeve gastrectomy is a procedure where the provider surgically decreases the size of the stomach. “We’re just taking a part off and making the stomach smaller. The patient is going to eat less, and that’s going to help with digestion,” explained Crystal Watters, CPC, CGSC, member of the American Society for Metabolic and Bariatric Surgery (ASMBS) during her session, “The Skinny on Bariatric Surgery and Medical Weight Loss Management,” at AAPC’s HEALTHCON 2025.

With a sleeve gastrectomy, the surgeon isn’t moving organs around and creating new connections; they’re simply making the stomach smaller. You’ll assign 43775 (Laparoscopy, surgical, gastric restrictive procedure; longitudinal gastrectomy (ie, sleeve gastrectomy)) to report a sleeve gastrectomy procedure.

This procedure is also known as a gastric sleeve or a sleeve. If you see these terms in the surgical report, chances are good that you’ll use 43775 to report the procedure.

Recognize Roux-en-Y Gastric Bypass Surgeries

A Roux-en-Y gastric bypass surgery involves connecting a portion of the stomach directly to the small intestine at the jejunum. Essentially, this is converting the digestive path. “When I think of conversion, we’re going to talk about moving the plumbing around. When I think about it, I think of the old school switchboard operators connecting incoming phone calls to their intended recipient,” Watters explained.

The surgeon creates a small gastric pouch, about two tablespoons in size, at the top of the stomach. The physician then splits the small intestine into two limbs — the duodenum at the beginning of the small intestine becomes the biliopancreatic limb and the Roux limb is the middle portion of the small intestine (also known as the jejunum). The biliopancreatic limb contains the digestive fluids from the stomach and pancreas. The surgeon connects the stomach’s gastric pouch to the Roux limb where food combines with the digestive juices and continues along the digestive path.

Your CPT^® code choices depend on the length of the Roux limb. Use 43644 (Laparoscopy, surgical, gastric restrictive procedure; with gastric bypass and Roux-en-Y gastroenterostomy (roux limb 150 cm or less)) when the Roux limb is 150 cm or less, and you’ll assign 43645 (… with gastric bypass and small intestine reconstruction to limit absorption) when the Roux limb is more than 150 cm long.

Even though the descriptor for 43645 does not include a Roux limb length, the CPT^® code book features a parenthetical note instructing you to use the code for a limb greater than 150 cm.

Understand the BPD-DS Procedure

The biliopancreatic diversion with duodenal switch is a gastric bypass surgery that is also known as BPD-DS or a switch. The surgery involves making the stomach smaller (gastric sleeve) and creating anastomoses (connections) in the digestive tract.

The surgeon divides the duodenum past the pylorus, and then the provider connects the ileum (last section of the small intestine) up to the pylorus. The food bypasses the jejunum and rejoins the digestive path as a common channel that flows into the colon.

“We use this for patients with a higher body mass index [BMI]. Our real high BMI patients. Not only are we changing the shape of their stomach, making it smaller, but the physician is also making sure the patient still receives all their digestive juices, so the food digests normally,” Watters said.

You’ll use an unlisted code to report a laparoscopic BPD-DS surgery. Assign 43659 (Unlisted laparoscopy procedure, stomach) and include 43845 (Gastric restrictive procedure with partial gastrectomy, pylorus-preserving duodenoileostomy and ileoileostomy (50 to 100 cm common channel) to limit absorption (biliopancreatic diversion with duodenal switch)) as your comparison code.

Comparison code: A comparison code is a procedure code that is similar to the unlisted procedure performed. The comparison code allows the payer to consider accurate reimbursement for the surgeon’s work. The code must represent a surgery performed on the same body area. With the codes listed above, 43659 is an unlisted laparoscopic stomach surgery code and 43845 is an open BPD-DS procedure.

Solidify Your SADI Coding Knowledge

During a SADI surgery, the surgeon performs a sleeve gastrectomy to restrict food intake and control hunger. Following the sleeve, the intestines are rerouted like in the aforementioned bypass procedures. The provider creates a single anastomosis between the stomach outlet and further along the small intestine, which then connects to the base of the large intestine.

“Basically, what we did with the BPD-DS is we had two anastomoses for the bypass surgery. Now, we just have one, and what do we know about anytime we have only one anastomosis? We have less chance for leaking. So instead of having to keep an eye on two anastomoses, we only have to keep an eye on one,” Watters said.

Similar to the BPD-DS, you’ll use an unlisted code to report this procedure. Assign 44238 (Unlisted laparoscopy procedure, intestine (except rectum)) with a comparison code. Watters recommended using 44202 (Laparoscopy, surgical; enterectomy, resection of small intestine, single resection and anastomosis) appended with modifier 52 (Reduced services) as the comparison code for a single-loop SADI and +44203 (Laparoscopy, surgical; each additional small intestine resection and anastomosis (List separately in addition to code for primary procedure)) appended with modifier 52 as the comparison code for a double-loop SADI.

Modifier 52 is needed “because we’re not resecting the actual small intestines; we’re just rerouting them,” Watters said.

You’ll also use 43775 to report the sleeve gastrectomy portion of the surgery.

Break Down Coding Barriers

The CPT^® code book does not contain codes for as many laparoscopic procedures as are needed to report bariatric surgeries. Many of the procedures performed each year are revisions to previously performed surgeries. However, coders are left reporting unlisted codes for the surgeon’s work.

What should you do if the CPT^® code book doesn’t have an accurate comparison code? “Ask your surgeon,” Watters stated. “They have to know something that’s going on. Their name is on that claim,” she added. Open a dialogue with the surgeon and let them know that you’re trying to get them their compensation.

“It will make your job infinitely easier, and it will make them happier,” Watters said.

Mike Shaughnessy, BA, CPC, Development Editor, AAPC