Outpatient and Physician Reporting of Biliary Procedures

by Jackie Miller, RHIA, CPC

Coding biliary procedures requires in-depth knowledge of anatomy as well as coding guidelines. This article outlines the correct coding for biliary procedures in outpatient and physician settings.

The Biliary System

The biliary system consists of the organs and structures that secrete and transport bile, including the liver, gallbladder, and bile ducts. Interventional radiologists can perform diagnostic imaging of the biliary system as well as procedures for relief of biliary obstruction.

Bile is secreted by the liver and drains into small ducts called intrahepatic biliary radicles. The radicles on the right and left sides of the liver drain into the right and left hepatic ducts. The two hepatic ducts then join to form the common hepatic duct.

The gallbladder is a sac-like structure that stores and concentrates bile. Bile drains from the gallbladder through the cystic duct. The cystic duct joins with the common hepatic duct to form the common bile duct, which empties into the duodenum.

Obstruction of the biliary system can be caused by calculi (gallstones), cancer, infection, cirrhosis, trauma, or other factors. Biliary obstruction needs to be treated promptly because it can cause pain, jaundice, infection, and tissue damage.

The Biliary System

Diagnostic Imaging

Diagnostic imaging of the biliary system is performed by passing a needle through the liver into one of the intrahepatic bile ducts. Contrast is then injected into the bile duct under fluoroscopy. This procedure is known as a percutaneous transhepatic cholangiogram (PTC). It is reported with CPT codes 47500, Injection procedure for percutaneous transhepatic cholangiography, and 74320, Cholangiography, percutaneous, transhepatic, radiological supervision and interpretation.

Modifier 26, Professional component, must be added to 74320 and all other supervision and interpretation codes discussed in this article when the supervision and interpretation code is reported by a physician who provided only the professional component; for example, when the exam is performed in the hospital setting.

Diagnostic imaging studies can also be performed on patients who have a biliary drainage catheter in place. For example, a surgeon may leave a T-tube (a self-retaining drainage tube shaped like a T) in place at the time the gallbladder is removed, and the interventional radiologist may be asked to perform an imaging study via the tube to confirm that there are no remaining gallstones. In other cases an imaging study may be performed on a nonsurgical patient who has had a drainage catheter placed percutaneously due to biliary obstruction.

In these situations the radiologist can perform a cholangiogram by simply injecting contrast into the existing tube or catheter. This procedure is often referred to as a T-tube cholangiogram. It is reported with codes 47505, Injection procedure for cholangiography through an existing catheter (e.g., percutaneous transhepatic or T-tube), and 74305, Cholangiography and/or pancreatography; through existing catheter, radiological supervision and interpretation.

Biliary Drainage Procedures

Interventional radiologists commonly perform three types of biliary drainage procedures.

External biliary drainage is performed by positioning a drainage catheter in the bile duct above the obstruction. The physician punctures the skin and passes a needle into one of the bile ducts. The needle is exchanged over a guidewire for a catheter, and the catheter is positioned and sutured in place. All of the bile then drains out of the body through the catheter into a collection bag. Sometimes two separate catheters are used to drain the right and left biliary ductal systems.

External biliary drainage is reported with codes 47510, Introduction of percutaneous transhepatic catheter for biliary drainage, and 75980, Percutaneous transhepatic biliary drainage with contrast monitoring, radiological supervision and interpretation.

Internal-external biliary drainage procedures are performed to allow bile to drain past an area of obstruction. The physician punctures the biliary tract percutaneously and advances a catheter down the bile duct past the obstruction. The catheter is exchanged over a guidewire for a biliary drainage catheter, which is left to external gravity drainage. Often the external end of the catheter can be capped after a few days so that all the bile drains internally (into the duodenum).

Internal-external biliary drainage is reported with codes 47511, Introduction of percutaneous transhepatic stent for internal and external biliary drainage, and 75982, Percutaneous placement of drainage catheter for combined internal and external biliary drainage or of a drainage stent for internal biliary drainage in patients with an inoperable mechanical biliary obstruction, radiological supervision and interpretation.

Internal biliary drainage is performed in patients with chronic biliary obstruction, especially those with obstruction due to cancer that cannot be treated surgically. The radiologist places an internal biliary stent, a segment of plastic or metal tubing, into the narrowed area of the bile duct. The stent is completely internal; that is, no part protrudes outside the patient’s body.

An internal stent may be placed as an initial procedure, or it may be placed after the patient has had an external or internal-external drainage catheter in place for a period of time.

There are several potential coding scenarios for placement of an internal biliary stent. Code 47801, Placement of choledochal stent, is frequently used for this procedure. Code 47556, Biliary endoscopy, percutaneous via T-tube or other tract; with dilation of biliary duct stricture(s) with stent, also incorporates placement of an internal biliary stent. However, code 47556 is defined as an endoscopy procedure, and an endoscope is typically not used for stent placement when the procedure is performed by interventional radiologists. Additionally, the American Medical Association has advised, “It is not appropriate to report an endoscopy CPT code (e.g., 47555) when a nonendoscopic procedure is performed.”1

It should be noted that code 47801 is classified by the Centers for Medicare and Medicaid Services as an inpatient-only procedure.

The imaging guidance for placement of an internal stent without bile duct dilation is reported with code 75982. If bile duct dilation is also performed, the guidance should be reported with code 74363, Percutaneous transhepatic dilation of biliary duct stricture with or without placement of stent, radiological supervision and interpretation.

Diagnostic Cholangiogram with Drainage

Frequently a diagnostic cholangiogram will be performed prior to insertion of a biliary drainage catheter or stent. If a medically necessary diagnostic cholangiogram is performed and documented, both the cholangiogram and the drainage procedure should be coded.

When a PTC is followed by placement of an external or internal-external biliary drainage catheter, modifier 59 should be applied to the cholangiogram codes (47500 and 74320) to indicate that they represent a separate diagnostic procedure rather than the imaging used to insert the drain.

Currently there are no Correct Coding Initiative edits for PTC performed in conjunction with placement of an internal biliary stent, so modifier 59 is not required in this situation.

Multiple Drainage Catheters

According to the Society of Interventional Radiology, if the radiologist places two drainage catheters via separate punctures to drain the left and right biliary ductal systems, two drainage procedures should be reported.2 Depending on payer policy, it may be necessary to append modifier 59 or 51 to the second drainage procedure code. Modifiers RT and LT should generally not be used in this situation because most payers do not recognize these codes as bilateral.

Staged Procedures

Often an external or internal-external drainage catheter is converted to a completely internal stent once the patient’s biliary system has decompressed. Biliary drainage procedures (47510, 47511, and 47801) have a 90-day Medicare global period for physician billing. If a staged procedure is performed during the global period of the original procedure, modifier 58, Staged or related procedure or service by the same physician during the postoperative period, should be applied to the CPT code for the second procedure.

For example, if a patient undergoes internal-external drainage (47511) followed one week later by internal stent placement (47801), the physician should apply modifier 58 to the stent placement code (47801-58).

Because global surgical periods do not apply to hospital billing, no modifier is typically needed on the hospital’s claim for the stent placement.

Catheter Change

Removal and replacement of an external or internal-external biliary drainage catheter is reported with codes 47525, Change of percutaneous biliary drainage catheter, and 75984, Change of percutaneous tube or drainage catheter with contrast monitoring (e.g., genitourinary system, abscess), radiological supervision and interpretation. Removal and replacement of a T-tube is reported with code 47530, Revision and/or reinsertion of transhepatic tube, and 75984.

When a patient presents for a scheduled tube change, a diagnostic cholangiogram is not typically reported. However, if a medically necessary diagnostic cholangiogram is performed and documented, and the decision to replace the drainage tube is based on the results of the cholangiogram, then both the cholangiogram and the tube change can be reported. This most often occurs when the patient presents for evaluation of a nonfunctioning drainage tube, rather than in conjunction with a routine tube change.

Catheter Removal

There is no code for removal of an external or internal-external biliary catheter. For physician billing, the catheter removal is included in the insertion when the catheter is removed during the 90-day global period. For hospital billing, it may be appropriate to report a low-level clinic visit code for the encounter during which the tube is removed, depending upon the hospital’s visit classification criteria.


  1. American Medical Association. Handout for the CPT 2005 Coding Symposium. Chicago, IL. 2004, page 1.
  2. Society of Interventional Radiology. Interventional Radiology Coding Users’ Guide, 14th ed. Fairfax, VA: SIR, 2007.


American Medical Association. CPT 2008. Chicago, IL: AMA, 2007.

Covey, Anne M., and Karen T. Brown. “Palliative Percutaneous Drainage in Malignant Biliary Obstruction, Part 1: Indications and Preprocedure Evaluation.” Journal of Supportive Oncology 4, no. 6 (June 2006): 269. Available online at www.supportiveoncology.net/journal/articles/0406269.pdf.

Covey, Anne M., and Karen T. Brown. “Palliative Percutaneous Drainage in Malignant Biliary Obstruction, Part 2: Mechanisms and Postprocedure Management.” Journal of Supportive Oncology 4, no. 7 (July/August 2006): 329. Available online at www.supportiveoncology.net/journal/articles/0407329.pdf.

Jackie Miller (jackie.miller@codingstrategies.com) is senior consultant at Coding Metrix in Powder Springs, GA.

Article citation:
Miller, Jackie. "Outpatient and Physician Reporting of Biliary Procedures" Journal of AHIMA 79, no.10 (October 2008): 102-104.