ICD-10 code T85.631A: Leakage of intraperitoneal dialysis catheter

ICD-10 code T85.631A is a billable diagnosis code for leakage of an intraperitoneal dialysis catheter at the initial encounter. It applies when a peritoneal dialysis catheter develops a breach and dialysate escapes the intended circuit. The A suffix marks an encounter where the patient is still under active treatment for that leakage.

Report it with Z99.2 for dialysis dependence and the underlying CKD or ESRD code. The code took effect on October 1, 2025 and is valid for FY2026 HIPAA-covered transactions.

Key takeaways

T85.631A is a billable ICD-10-CM code for leakage of intraperitoneal dialysis catheter, initial encounter, valid for HIPAA-covered transactions in FY2026.

The 7th character suffix A (initial), D (subsequent), or S (sequela) sets the encounter type. Choosing the wrong one is a common denial trigger.

Z99.2 (dependence on renal dialysis) and the underlying CKD or ESRD code should be reported alongside T85.631A per use-additional-code instructions.

An infection of the same catheter is coded to T85.71, not to T85.631A or the T80-T82 range.

Pabau’s claims management software integrates with Claim.MD to support accurate ICD-10 submission and real-time eligibility checks for dialysis encounters.

ICD-10 code T85.631A: Quick reference details

ICD-10 code T85.631A became effective on October 1, 2025 as part of the FY2026 ICD-10-CM release. It is a billable, specific code valid for submission on HIPAA-covered transactions. The table below captures the administrative facts coders need at a glance.

Clinical description: What does T85.631A represent?

Peritoneal dialysis catheter leakage occurs when the catheter used to deliver and drain dialysate in the peritoneal cavity develops a breach. Fluid escapes from the intended circuit into adjacent tissues, the subcutaneous space, or externally at the exit site.

The complication is mechanical rather than infectious, so it sits in the T85.6 mechanical range. An infection of the same catheter is coded to T85.71 instead, not to the T80-T82 range.

Almost every patient affected has end-stage renal disease (ESRD, N18.6) or advanced chronic kidney disease (CKD). They rely on peritoneal dialysis because their kidneys can no longer filter waste adequately.

PD uses the peritoneum as a semipermeable membrane. Dialysate is instilled through the catheter, waste diffuses across the membrane, and the spent fluid is drained. A leaking catheter disrupts that cycle, which can compromise dialysis adequacy and needs urgent clinical attention.

• Common leakage sites: Exit site, subcutaneous tunnel, cuff, or intra-abdominal catheter body
• Typical causes: Catheter defect, cuff extrusion, increased intraperitoneal pressure, inadequate healing post-insertion
• Clinical presentation: Pericatheter fluid drainage, abdominal wall edema, reduced drain volumes, or fluid imbalance
• Management: Temporary transfer to hemodialysis, catheter repair, or catheter replacement depending on severity

T85.631A in the ICD-10-CM code hierarchy

Knowing where T85.631A sits in the hierarchy helps coders reach the right level of specificity and avoid non-billable parent codes. The code falls under the broad T85 category for complications of other internal prosthetic devices.

Only the 7th-character codes (T85.631A, T85.631D, T85.631S) are billable. Submitting T85.631 or T85.63 on a claim will result in rejection, because these parent codes lack the specificity a HIPAA-covered transaction requires.

Encounter type suffixes: A, D, and S for T85.631

The 7th character extension is one of the most common sources of claim errors on T85.631-series codes. Each suffix signals a distinct phase of care and must match the clinical context documented in the record.

A key rule: The suffix A does not mean “first visit to this provider.” It means the patient is still receiving active treatment for the condition.

If the leakage has been treated and the patient returns for a wound check, suffix D is correct even with the same provider. Misapplying A where D belongs is a top source of inpatient claim errors on device complication codes.

Approximate synonyms for T85.631A

ICD-10-CM recognizes several alternate descriptions for this condition. Coders may meet any of these terms in clinical documentation and should map them to T85.631A for initial-encounter claims.

• Leaking peritoneal dialysis catheter, initial encounter
• Leakage of peritoneal dialysis catheter, initial encounter
• Intraperitoneal dialysis catheter leakage, initial encounter
• IP dialysis catheter leakage, first encounter
• Mechanical complication of peritoneal dialysis catheter (leakage type), initial encounter
• Peritoneal catheter fluid leak, initial encounter

Clinical notes may say “pericatheter leak,” “dialysate leak,” or “catheter egress site drainage.” Coders should confirm the documentation names the intraperitoneal catheter as the device involved. If it does, T85.631A is the correct code for an initial-encounter claim. For a leak in a different internal device, use T85.638A.

Related ICD-10-CM codes for peritoneal dialysis catheter complications

T85.631A sits within a broader family of codes covering mechanical complications of the peritoneal dialysis catheter and other internal devices. Knowing the sibling codes helps coders pick the right one when the complication type is not leakage.

Use T85.691A when the catheter complication does not fit the leakage, displacement, or obstruction categories. For infection-related complications such as PD catheter peritonitis, code T85.71 (Infection and inflammatory reaction due to peritoneal dialysis catheter) rather than T85.631A. T85.631A is strictly for mechanical leakage.

The panel below maps both decisions a coder makes on these claims: Which complication code applies, and which encounter suffix goes with it.

Coding guidelines for T85.631A

The ICD-10-CM Official Guidelines for Coding and Reporting, maintained by CMS and NCHS, carry specific instructions that apply to T85.631A. Getting these right prevents the most common billing errors on dialysis complication claims.

Additional codes to report with T85.631A

ICD-10-CM includes use-additional-code instructions for T85.631A. Coders should report the following secondary codes alongside it where documented and applicable:

• Z99.2 (Dependence on renal dialysis): Report this code to show the patient’s ongoing dialysis dependence. It applies to virtually all peritoneal dialysis patients and signals the chronic need for the device in question.
• N18.x (Chronic kidney disease, stage x): Report the specific CKD stage code to capture the underlying kidney disease. N18.6 (ESRD) is the most common in peritoneal dialysis patients.
• Underlying condition code: The CKD may have a documented etiology such as diabetic nephropathy or hypertensive CKD. That condition code may also be appropriate per sequencing guidance.

Confirm the use-additional-code notation in your FY2026 ICD-10-CM tabular before relying on it. A pre-submission check that flags missing secondary codes costs far less than an appeal after rejection.

POA (Present on admission) indicator

For inpatient claims, T85.631A requires a Present on Admission (POA) indicator. The indicator tells the payer whether the catheter leakage was present when the patient was admitted or developed during the hospital stay.

POA indicators apply to inpatient facility claims only. Outpatient and physician claims do not require one. An inpatient claim carrying T85.631A without a valid POA indicator may pend or reject, depending on the payer. Build a POA review step into the pre-submission check for every inpatient device complication code.

Clinical documentation requirements for T85.631A

Insufficient documentation is the most common reason a correct code assignment still gets denied. The record must support each element of T85.631A at the specificity the code demands.

The medical record should document all of the following to support T85.631A on a claim:

• Device identification: The note must name the intraperitoneal dialysis catheter as the specific device involved, not a generic “catheter” or “line.”
• Nature of complication: Documentation must describe leakage, fluid escape, or a breached catheter system, distinct from obstruction, displacement, or infection.
• Encounter phase: The note should indicate whether this is the first active management encounter (suffix A) or a follow-up after initial treatment (suffix D).
• Dialysis dependence: Confirm the patient is actively receiving peritoneal dialysis for CKD or ESRD, supporting the Z99.2 secondary code.
• Underlying condition: The CKD stage or ESRD diagnosis should appear in the problem list or assessment, supporting the N18.x code sequence.
• Plan of care: Documentation of the clinical response (catheter repair, hemodialysis transfer, conservative management) helps confirm active treatment for the A suffix.

Coders who receive a note saying only “dialysis catheter problem” should query the treating physician. A charge-capture form that requires the device name and the encounter phase before sign-off cuts that query volume.

ICD-9-CM crosswalk for T85.631A

Legacy system integrations, payer crosswalk tools, and historical records may still reference ICD-9-CM codes. The approximate ICD-9-CM equivalent for T85.631A is shown below. ICD-9-CM did not capture the same device-and-complication specificity as ICD-10-CM, so a one-to-one equivalence does not exist.

Always label ICD-9-CM crosswalks as approximate when documenting or communicating them. ICD-9 code 996.56 covered obstruction, leakage, and displacement under one code, whereas ICD-10-CM separates them into distinct billable codes. Per ResDAC’s guidance on ICD codes in Medicare files, the transition to ICD-10 added clinical specificity that backward crosswalks cannot fully capture.

Billing and reimbursement: Submitting T85.631A claims

Clean claim submission for ICD-10 code T85.631A depends on correct sequencing, complete secondary codes, and a compliant claim format. Each of the three is a separate check before the claim goes out.

T85.631A is typically sequenced as an additional diagnosis when the patient presents primarily for dialysis management. Where the leakage is the principal reason for the admission or encounter, it may sequence as the principal diagnosis. Follow the official ICD-10-CM sequencing rules and confirm with your compliance team.

Practice management software like Pabau integrates with Claim.MD, our US clearinghouse partner, to support clean claim submission for codes like T85.631A. The integration covers real-time eligibility verification, electronic claims to thousands of US payers, and electronic remittance advice (ERA) processing.

Built-in ICD-10 and CPT code catalogues let billing teams check code specificity before submission, so a parent code like T85.631 never reaches the payer. For practices with ongoing peritoneal dialysis patients, clearinghouse claims submission workflows also validate secondary code completeness before transmission.

When a claim does reject, the remittance returns CARC reason codes that name the failure. Matching those denial codes to the missing element shows whether to fix a code or add documentation.

How Pabau supports dialysis complication coding accuracy

Nephrology and dialysis billing teams handle a high volume of device complication codes. Documentation quality and code specificity decide the claim outcome on almost all of them. Pabau’s claims software for practices cuts the manual steps between the clinical note and a clean claim.

• Built-in ICD-10 code catalogue: A searchable ICD-10-CM library lets billing staff find T85.631A and confirm its billable status without leaving the claim.
• Claim.MD integration: Electronic claim submission to thousands of US payers, with real-time eligibility checks before the encounter.
• ERA processing: Automated 835 remittance ingestion posts payments and flags denials with CARC codes, so T85.631A rejections surface within days.
• Secondary and corrected claims: Pabau supports secondary and corrected claim workflows through Claim.MD, covering T85.631A encounters that involve more than one payer.

For dialysis practices juggling ESRD patients with several device complications, structured documentation and automated claim validation together lower the per-claim error rate.

Accurate ICD-10 coding starts with better documentation workflows

Pabau integrates with Claim.MD to support clean claim submission for dialysis catheter complication codes. Real-time eligibility checks, built-in ICD-10 code catalogues, and automated ERA processing help nephrology billing teams reduce denials and get paid faster.

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Conclusion

The code itself is the easy part of a T85.631A claim. The note behind it decides the outcome, because it has to name the device, describe the leakage, and fix the encounter phase.

Build the secondary codes into the check rather than the appeal. A coder who confirms Z99.2 and the CKD stage before transmission removes the two most common rejection reasons on these encounters.

Book a demo to see how Pabau validates ICD-10 specificity and submits dialysis complication claims in one workflow.

Continue your research

Need to understand how clearinghouse submission works end to end? Medical claims clearinghouse guide covers how clearinghouses validate, route, and track electronic claims for US practices.

Want to reduce ICD-10 denial rates across your billing team? Denial management in healthcare outlines the systematic approach to identifying, appealing, and preventing common claim denials.

Looking for a structured billing compliance checklist? Medical billing compliance guide covers the documentation, coding, and submission standards that reduce audit and denial risk.

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