Medical Coding Deep Infiltrative Endometriosis (DIE)

Medical Coding Deep Infiltrative Endometriosis (DIE): Guidelines & Tips

Deep infiltrative endometriosis (DIE) is a severe form of endometriosis where endometrial-like tissue penetrates more than 5 mm below the peritoneal surface. It often affects multiple pelvic structures — including the peritoneum, bladder, rectum, uterosacral ligaments, and bowel — and can cause chronic pelvic pain, infertility, and organ dysfunction.

Because these lesions may span several anatomical sites, accurate ICD-10-CM coding requires careful review of the operative note and pathology report to identify all affected structures.

Commonly Involved Sites

• Peritoneum – the most frequent location for DIE

• Bladder – may cause urinary frequency, dysuria, or hematuria

• Rectum or rectovaginal septum – often results in painful defecation

• Uterosacral ligaments or cul-de-sac – associated with severe pelvic pain

• Bowel or sigmoid colon – may mimic IBS symptoms

• Vagina or cervix – less common but possible

ICD-10-CM Coding

Primary Codes

All endometriosis codes are found in Chapter 14 (N80) of ICD-10-CM.
Select the code based on the specific anatomic site(s) documented.

If multiple sites are affected (e.g., peritoneum and rectum), assign multiple codes to capture each involved structure.

How to choose the correct DIE code

1. Review the medical documentation: The coder must look for precise language in the surgeon’s or clinician’s notes that explicitly states “deep infiltrating,” “deep,” or “infiltrating” alongside the specific organ or tissue involved.
2. Identify the location: Determine which organ or pelvic structure is affected by the DIE.
3. Find the corresponding code: Navigate the ICD-10-CM table to find the N80 series and then select the code that specifies both the location and “deep” involvement.
4. Confirm the specificity: Choose the most detailed and specific code available to accurately reflect the patient’s condition. 

Documentation Tips

Accurate coding depends on detailed provider documentation. Encourage providers to specify:

• Exact anatomic site(s) and depth of invasion

• Laterality (if applicable)

• Extent of organ involvement (e.g., partial vs. full-thickness bladder wall invasion)

• Associated complications (obstruction, adhesions, infertility)

• Procedural details if surgical excision or lysis of adhesions is performed

Surgical procedures

Coding Tips

1. Use multiple codes when more than one pelvic organ is involved.
   Example:

   • Endometriosis of the peritoneum (N80.3)

   • Endometriosis of intestine (N80.5)

   • Endometriosis of bladder (N80.8)

2. Do not default to N80.9 unless documentation is vague. Clarify with the provider before using “unspecified.”

3. Procedural coding (CPT) may be required for laparoscopic excision, fulguration, or resection. Examples include:

   • 58662 – Laparoscopy, excision or destruction of lesions

   • 58670 – Laparoscopy, fulguration of oviducts (sterilization, if performed)

   • 49320 – Diagnostic laparoscopy (if only diagnostic)

4. Endometriosis of the bowel or urinary tract can also be clinically significant enough to require concurrent general surgery or urology codes — review operative notes carefully.

5. If infertility or pelvic pain is documented, consider coding the symptom or complication separately when appropriate (e.g., N97.9 Infertility, unspecified).

Example Coding Scenario

Operative Report:
Laparoscopic excision of deep infiltrative endometriosis involving the pelvic peritoneum, posterior bladder wall, and rectovaginal septum.

Codes:

• N80.3 – Endometriosis of pelvic peritoneum

• N80.8 – Endometriosis of the bladder

• N80.4 – Endometriosis of rectovaginal septum and vagina

• CPT 58662 – Laparoscopic excision or destruction of lesions

Key Takeaways

• Always code to the deepest, most specific location identified.

• Use multiple diagnosis codes when multiple pelvic organs are affected.

• Encourage providers to document the extent of invasion (superficial vs. deep).

• Cross-reference ICD-10-CM with CPT/HCPCS codes for procedures.

Understanding Deep Endometriosis: From Molecular to Neuropsychiatry Dimension 

Historic Update to ICD-10 Endometriosis Diagnosis Codes 

Coding Endometriosis With Improved Specificity 

Medical Coding Blog