N32.81

🧬 ICD-10 CM N32.81 — Overactive Bladder

Billable Code Confirmed

ICD-10-CM N32.81 is a valid, billable 5-character ICD-10-CM code for FY2026. Characters 1-3 (N32) identify the category (other disorders of bladder); character 4 (8) identifies the “other specified disorders of bladder” subcategory (N32.8); character 5 (1) specifies the overactive bladder subtype. No additional characters are available or required — N32.81 is a fully specified, terminal code.

Non-Billable Parent Codes — Never Submit These

• ❌ N32 — 3-character header — missing specificity of bladder disorder type
• ❌ N32.8 — 4-character subcategory — “other specified disorders of bladder” — missing the 5th character distinguishing overactive bladder (N32.81) from other specified (N32.89)

Always submit N32.81 (all 5 characters) when overactive bladder is the documented clinical diagnosis. When urinary frequency or urgency is a symptom of another documented bladder condition (cystitis, BPH, bladder calculus), code the underlying condition — not N32.81.

Clinical Context: N32.81 Is an Established Diagnosis Code, Not a Symptom Code

ICD-10 CM N32.81 is appropriate only when the provider has diagnosed overactive bladder (OAB) as a clinical entity after appropriate workup excluding infection, obstruction, and neurological causes. It should never be assigned for urinary frequency or urgency that is attributable to a separately documented and more specific condition. When OAB coexists with urge incontinence (N39.41) or mixed incontinence (N39.46), both codes may and should be reported together — N32.81 captures the condition (OAB) and the N39.4x code captures the incontinence manifestation.

Code Classification

ICD-10 CM Diagnosis Code — wRVU, global surgical period, and assistant-at-surgery fields are not applicable to this diagnosis code. N32.81 is one of the most important covered diagnoses for high-cost urology procedures including bladder Botox (CPT 52287), PTNS (CPT 64566), and sacral nerve stimulation (CPT 64561, 64581). For associated inpatient procedures, refer to the ICD-10-PCS Crosswalk section. For profee billing context, refer to the Commonly Associated CPT Codes section.

---

🔍 Code Description

ICD-10 CM N32.81 classifies overactive bladder (OAB) — a syndrome defined by the International Continence Society (ICS) as urinary urgency, usually accompanied by urinary frequency (>8 voids/24 hours) and nocturia, with or without urge urinary incontinence, in the absence of urinary tract infection or other obvious pathology. The underlying pathophysiology involves involuntary, uninhibited contractions of the detrusor muscle during the bladder filling phase, generating a sudden urge to void that is difficult to defer.

The ICD-10 CM Includes note specifies that detrusor muscle hyperactivity maps to N32.81. OAB is considered “wet” when accompanied by urge incontinence (code N39.41 additionally) and “dry” when urgency and frequency occur without leakage. The diagnosis is clinical — supported by voiding diary documentation (>8 voids/day, nocturia), and confirmed after exclusion of UTI, bladder outlet obstruction, and neurological disease via urodynamic testing showing uninhibited detrusor contractions. When a specific neurological etiology is identified as the cause of detrusor overactivity (stroke, MS, Parkinson’s), the neurological diagnosis should also be coded, and if the neurogenic mechanism is primary, consider whether N31.0 (uninhibited neuropathic bladder) is more accurate.

---

🌳 Code Tree / Hierarchy

N32    Other disorders of bladder ❌ Non-billable (3-char header)
│
├── N32.0   Bladder-neck obstruction ✅ Billable
├── N32.1   Vesicointestinal fistula ✅ Billable
├── N32.2   Vesical fistula, not elsewhere classified ✅ Billable
├── N32.3   Diverticulum of bladder ✅ Billable
│
├── N32.8   Other specified disorders of bladder ❌ Non-billable (4-char subcategory)
│    │
│    ├── N32.81  Overactive bladder ◀ THIS CODE ✅ Billable
│    └── N32.89  Other specified disorders of bladder ✅ Billable
│
└── N32.9   Bladder disorder, unspecified ✅ Billable

N32.81 vs. N31.0 — OAB vs. Uninhibited Neuropathic Bladder

N32.81 (overactive bladder) and N31.0 (uninhibited neuropathic bladder, NEC) both involve involuntary detrusor contractions, but code selection hinges on whether a specific neurological cause is documented. N32.81 = idiopathic or non-neurogenic OAB (no identified neurological etiology after workup). N31.0 = neurogenic uninhibited bladder with a documented supraspinal neurological cause (stroke, MS, Parkinson’s dementia). When the urologist or neurologist explicitly documents that the OAB is neurogenic in origin, N31.0 is the appropriate code — and it carries Excludes 1 restrictions (spinal cord lesion → G95.89) that N32.81 does not. Query the provider when documentation is ambiguous between idiopathic OAB and neurogenic bladder overactivity.

---

✅ Includes

The following clinical terms and scenarios map to N32.81 when documented:

• Overactive bladder (OAB) — provider has established the diagnosis after clinical workup
• Detrusor muscle hyperactivity — as specified in the ICD-10-CM Includes note
• OAB-dry: urgency and frequency without documented incontinence
• OAB-wet: urgency and frequency WITH urge incontinence (also code N39.41 or N39.46 per documentation)
• Idiopathic detrusor overactivity confirmed on urodynamic testing (uninhibited detrusor contractions, no neurological cause identified)
• Urinary urgency-frequency syndrome, diagnosed and documented by provider as OAB

---

❌ Excludes

Excludes 1 — Cannot Be Coded Simultaneously with N32.81

Code	Description	Note
[Frequency due to specified condition]	Frequent urination due to specified bladder condition — Code to condition	If urinary frequency is a symptom of a documented underlying condition (e.g., cystitis N30.00, BPH with LUTS N40.1, bladder calculus N21.0), code that condition — the frequency is integral to the underlying diagnosis and N32.81 must NOT also be assigned. This Excludes 1 applies at the N32 category level.

Excludes 1 Risk — Do Not Code N32.81 When Another Condition Explains the Frequency/Urgency

The most important Excludes 1 application for N32.81: if the provider has documented a specific bladder condition (acute or chronic cystitis, BPH, interstitial cystitis, bladder calculus) that causes urinary frequency or urgency, code that condition — not N32.81. Overactive bladder is specifically a diagnosis made after other causes are excluded. Assigning N32.81 alongside a documented cause of frequency (e.g., N30.00 acute cystitis) is an Excludes 1 violation because the frequency is integral to the cystitis. The exception: when OAB is separately documented as a coexisting condition independent of the other bladder pathology, both may be coded — but provider documentation must clearly support both diagnoses.

Excludes 2 — May Be Coded in Addition if Separately Present

Code	Description	Note
N21.0	Calculus of bladder	Bladder calculus may coexist with independently documented OAB — code both when separately documented and managed
N81.1-	Cystocele / Hernia or prolapse of bladder, female	Pelvic floor disorders may coexist with OAB; code both when separately documented — common in urogynecology encounters

---

📋 Clinical Overview

OAB Treatment Ladder — Coding Implications at Each Step

OAB follows a well-defined three-tier treatment ladder; each tier has distinct CPT coding implications, and N32.81 must be documented as the supporting diagnosis at each step to justify medical necessity.

Treatment Tier	Intervention	Key CPT Code(s)	Medical Necessity Requirement
First-Line	Behavioral therapy, fluid management, bladder training, pelvic floor PT	97110 (therapeutic exercises), 97530 (therapeutic activities)	N32.81 + voiding diary documentation
Second-Line	Anticholinergic medications (oxybutynin, tolterodine, solifenacin) or beta-3 agonist (mirabegron)	E/M visit only for prescription management (99213-99215)	N32.81 + documentation of symptom severity and impact
Third-Line	Botox intravesical injection (52287); Percutaneous Tibial Nerve Stimulation (64566); Sacral Nerve Stimulation trial/implant (64561, 64581)	See CPT table below	N32.81 + documentation of failed first- and second-line treatment; prior authorization typically required

Documentation Requirement for Third-Line Therapies

Before billing Botox (52287), PTNS (64566), or SNS (64561/64581) with N32.81 as the supporting diagnosis, the medical record must document failure of at least two prior lines of treatment (behavioral therapy AND at least one pharmacologic agent). Payers including CMS and most commercial insurers require this documentation for prior authorization and claims payment. Absence of this documentation is the most common reason for denial of these high-cost procedures even when N32.81 is correctly coded.

Clinical Diagnostic Criteria — What Documentation Must Support N32.81

Documentation should clearly establish OAB as a confirmed clinical diagnosis, not a symptom complaint:

• Voiding frequency: >8 voids per 24-hour period documented by voiding diary or patient history
• Urgency: Compelling, sudden urge to void difficult to defer — patient-reported and provider-documented
• Nocturia: ≥2 nocturnal awakenings to void (if present) — separately codeable as R35.1 if documented
• Exclusion of UTI: Urinalysis/urine culture negative or treated and resolved prior to OAB diagnosis
• Exclusion of obstruction: Documented PVR, uroflowmetry, or clinical assessment ruling out bladder outlet obstruction
• Exclusion of neurological cause: If neurological disease is present, confirm whether N31.0 vs. N32.81 is more accurate

R39.15 for Undiagnosed Urgency vs. N32.81 for Confirmed OAB

Use R39.15 (urinary urgency) when the provider documents urgency as a symptom being evaluated — OAB not yet confirmed. Once the provider documents “overactive bladder” as a diagnosis after appropriate workup, N32.81 is correct. Do not assign both R39.15 and N32.81 simultaneously — when OAB is confirmed, the symptom code is subsumed.

---

💰 HCC Risk Adjustment (CMS-HCC v28)

Field	Detail
CMS-HCC Model Version	v28 (Fully implemented PY2026)
HCC Assignment	❌ Not HCC-Mapped
HCC Category	N/A
RAF Coefficient	N/A

N32.81 does not map to any HCC category under CMS-HCC v28 and does not independently contribute to RAF scoring.

Capture Underlying Neurological and Comorbid Conditions for RAF Impact

While N32.81 itself carries no HCC weight, the conditions that commonly cause or coexist with OAB frequently do. Always capture and code:

• Multiple sclerosis → G35.A — HCC 77 (when MS is the neurological driver of detrusor overactivity; note: in true MS-driven neurogenic bladder, consider whether N31.0 or G95.89 is more accurate vs. N32.81)
• Parkinson’s disease → G20.X — HCC 75
• Type 2 DM with neurological manifestations → E11.40 — HCC 18
• Chronic kidney disease (from obstructive or neurogenic uropathy) → N18.3-N18.5 — HCC 137-138 Each of these is separately HCC-mapped and should be coded at every qualifying encounter regardless of whether they are the focus of the OAB visit.

---

🏥 MS-DRG Assignment

MDC 11 — Diseases and Disorders of the Kidney and Urinary Tract

DRG	Title	Est. Relative Weight*
DRG 698	Other Kidney and Urinary Tract Diagnoses with MCC	~1.10-1.40
DRG 699	Other Kidney and Urinary Tract Diagnoses with CC	~0.80-1.00
DRG 700	Other Kidney and Urinary Tract Diagnoses without CC/MCC	~0.55-0.70

If a qualifying inpatient O.R. procedure is performed (e.g., sacral nerve stimulator implant, augmentation cystoplasty):

DRG	Title	Est. Relative Weight*
DRG 673	Other Kidney and Urinary Tract Procedures with MCC	~3.50-4.50
DRG 674	Other Kidney and Urinary Tract Procedures with CC	~2.00-2.80
DRG 675	Other Kidney and Urinary Tract Procedures without CC/MCC	~1.40-1.80

Approximate. Verify against IPPS FY2026 Final Rule Table 5 and your facility’s cost-to-charge ratios.

Inpatient Admission with N32.81 as PDx — Rare but Possible

Inpatient admissions with N32.81 as the principal diagnosis are uncommon since OAB is primarily managed outpatient. When they occur (e.g., patient admitted for inpatient sacral nerve stimulator implantation, or admitted with refractory OAB and a secondary complication), DRG tier depends on secondary CC/MCC burden. The underlying neurological condition (if coded alongside N32.81 as secondary) may function as a CC or MCC — verify using your facility’s DRG grouper. If sacral nerve stimulator implantation is performed inpatient, the ICD-10-PCS procedure codes (SNS lead + generator insertion) will shift the case from medical DRG 698-700 to surgical DRG 673-675.

---

🔗 Related ICD-10-CM Codes

N32 Bladder Disorder Family

Code	Description
N32.81	Overactive bladder ← This Code
N32.89	Other specified disorders of bladder
N32.0	Bladder-neck obstruction
N32.3	Diverticulum of bladder

Neurogenic vs. Idiopathic OAB Differentiation

Code	Description
N31.0	Uninhibited neuropathic bladder, NEC — use when OAB is neurogenic in etiology (supraspinal, non-spinal cord)
G95.89	Cord bladder NOS / neuromuscular dysfunction due to spinal cord lesion — use when OAB/detrusor overactivity is caused by spinal cord lesion

Associated Incontinence Codes (Commonly Reported with N32.81)

Code	Description
N39.41	Urge incontinence — most common incontinence code paired with N32.81 (OAB-wet)
N39.46	Mixed incontinence — when stress and urge components coexist
N39.3	Stress incontinence — separately coded when present alongside OAB

Symptom Codes (Use When OAB Not Yet Confirmed)

Code	Description
R39.15	Urinary urgency — symptom code; use when urgency is documented but OAB not yet confirmed
R35.0	Frequency of micturition — symptom code; use when frequency is the documented complaint without OAB diagnosis
R35.1	Nocturia — may be separately coded when documented alongside N32.81

---

🛠️ Commonly Associated CPT Codes (Urology / Urogynecology)

Outpatient and Ambulatory Surgery Setting Context

N32.81 is primarily an outpatient/ambulatory surgery code. It is the leading supported diagnosis for urodynamic testing (CMS LCD L35439) and for OAB neuromodulation therapies (CMS LCD for SNS and PTNS). Third-line treatments (Botox, PTNS, SNS) require prior authorization from most commercial and Medicare payers, with N32.81 listed as a qualifying covered diagnosis.

CPT Code	Description	Profee Coding Notes
52287	Cystourethroscopy with injection(s) for chemodenervation of the bladder	Botox intravesical injection — primary procedural CPT for OAB Botox; includes cystoscopic visualization; do NOT separately bill 52000; bill J0585 for drug (per unit onabotulinumtoxinA) in office setting; 0-day global period
64566	Posterior tibial neurostimulation, percutaneous needle electrode, single treatment, including programming	PTNS — 12-week weekly series typical; each session billed separately; N32.81 is supported covered diagnosis; prior auth required by most payers
64561	Percutaneous implantation of neurostimulator electrode array; sacral nerve (transforaminal placement)	SNS Stage 1 trial — percutaneous lead; used for both trial (temporary) and permanent leads depending on approach; bilateral placement possible
64581	Incision for implantation of neurostimulator electrode array; sacral nerve (transforaminal placement)	SNS Stage 1 trial — open incision approach; document approach clearly (percutaneous 64561 vs. open 64581)
64590	Insertion or replacement of peripheral or gastric neurostimulator pulse generator or receiver	SNS Stage 2 — generator implantation after successful trial; requires documentation of ≥50% symptom improvement during trial
51729	Complex cystometrogram with voiding pressure studies and urethral pressure profile studies	Full multichannel urodynamic study — most comprehensive; use Modifier -26 in facility setting; supported by CMS LCD L35439 with N32.81
51741	Complex uroflowmetry (calibrated electronic equipment)	Uroflowmetry — separately billable when medically necessary as distinct test; often performed as initial OAB workup
51784	Electromyography studies of anal or urethral sphincter, other than needle, any technique	Sphincter EMG — component of full urodynamic evaluation for OAB; separately billable per CMS LCD
51798	Measurement of post-voiding residual urine and/or bladder capacity by ultrasound, non-imaging	PVR measurement — commonly performed at OAB follow-up; separately billable; do NOT bill with a comprehensive renal/bladder ultrasound on the same date for the same anatomic area
99214	Office or other outpatient visit, established patient, moderate MDM	Most common E/M level for established OAB management visits; Modifier -25 required if billed same date as a urodynamic procedure or minor urologic procedure

NCCI Bundling Considerations

• Botox injection (52287) includes cystoscopic visualization — 52000 (diagnostic cystoscopy, separate procedure) is bundled and cannot be separately billed on the same date as 52287. Bill only 52287.
• PTNS (64566) cannot be billed with nerve conduction studies on the same date by the same provider — NCCI edit applies.
• SNS Stage 1 trial (64561 or 64581) and Stage 2 generator implant (64590) cannot be billed on the same date — these are staged procedures, typically separated by at least 7-14 days.
• Urodynamic components — simple CMG (51725) cannot be billed on the same day as complex CMG (51729); bill only the highest-level test performed. Sphincter EMG (51784) is separately billable alongside complex CMG when it is a distinct, medically necessary component.
• E/M + procedure same date — always append Modifier -25 to the E/M (99213, 99214) when billed on the same date as any urodynamic study or procedure. Document separately identifiable MDM in the E/M beyond pre-procedure assessment.

---

🔬 ICD-10-PCS Crosswalk (Inpatient Procedures)

When N32.81 is an inpatient diagnosis, these PCS codes are relevant for associated inpatient procedures.

PCS Section	Body System	Root Operation	Clinical Application
0 (Medical and Surgical)	J (Subcutaneous Tissue and Fascia)	H (Insertion)	SNS generator placement — 0JH60MZ (Abdomen Subcutaneous Tissue, Open); Stage 2 InterStim implant; paired with sacral lead
0 (Medical and Surgical)	1 (Central Nervous System and Cranial Nerves)	H (Insertion)	SNS sacral lead implantation — 01H00MZ (Into Lumbar Spinal Cord area, Open approach); or percutaneous approach variant; Stage 1 lead component
3 (Administration)	E (Physiological Systems and Anatomical Regions)	0 (Introduction)	Intravesical Botox injection — 3E0K3GC (Introduction of Other Therapeutic Substance into Genitourinary Tract, Percutaneous) — captures pharmacological chemodenervation of bladder wall
0 (Medical and Surgical)	T (Urinary System)	T (Resection) / U (Supplement)	Augmentation cystoplasty (rare, refractory OAB) — bladder enlargement procedure; Root Operation U (Supplement) or specific approach; verify PCS code against operative documentation

---

💊 Coding Scenarios and Examples

---

Scenario 1 — Outpatient Office: OAB with Urge Incontinence, Initial Pharmacologic Management

Clinical Vignette: A 58-year-old female presents to a urology clinic with a 6-month history of urinary urgency, voiding 12 times per day, and two or three episodes of urge incontinence per day. Urinalysis is negative for infection. PVR is 28 mL. Uroflowmetry demonstrates normal flow. The urologist reviews a voiding diary showing > 10 voids/day and 3 nighttime awakenings. She documents: “Overactive bladder (OAB-wet) — will start solifenacin 5 mg daily; discussed behavioral modifications.”

CPT (Profee):

• 99214 — Office visit, established patient, moderate MDM (OAB management with medication initiation; Modifier -25 not required if no same-day procedure)

ICD-10-CM:

• N32.81 — Overactive bladder (confirmed OAB diagnosis)
• N39.41 — Urge incontinence (documented OAB-wet pattern — separately coded per clinical documentation)
• R35.1 — Nocturia (3 nighttime awakenings separately documented — codeable when provider documents nocturia distinctly)

---

Scenario 2 — Outpatient ASC: Botox Bladder Injection for Refractory OAB

Clinical Vignette: A 67-year-old male with a 3-year history of overactive bladder has failed behavioral therapy, oxybutynin (discontinued due to side effects), and mirabegron (inadequate response after 3 months). He is referred for intravesical onabotulinumtoxinA (Botox) injection. The urologist performs cystourethroscopy and injects 100 units of Botox in 20 sites across the bladder wall (excluding the trigone). Drug: 100 units of onabotulinumtoxinA administered. Prior authorization on file documenting failure of two pharmacologic agents.

CPT (Profee):

• 52287 — Cystourethroscopy with injection(s) for chemodenervation of the bladder (one code covers all injection sites — do NOT separately bill 52000)

HCPCS Drug:

• J0585 — Injection, onabotulinumtoxinA, 1 unit (bill units = 100; billed separately for the drug in office/ASC setting when not separately packaged by facility)

ICD-10-CM:

• N32.81 — Overactive bladder (primary supported diagnosis for 52287)
• N39.41 — Urge incontinence (documented OAB-wet component)

---

Scenario 3 — CDI Query: OAB Documented with Active UTI — Code to Condition

Clinical Vignette: A 72-year-old female is seen in the urology clinic with complaints of urinary urgency and frequency. Urinalysis shows positive nitrites and leukocyte esterase. Urine culture grows E. coli. The provider’s assessment reads: “Overactive bladder — urinary frequency and urgency. Also with UTI — prescribing Macrobid.” The coder flags this for review.

Action / Outcome: Per the Excludes 1 note at the N32 category level, “frequent urination due to specified bladder condition — code to condition.” The patient’s urinary frequency and urgency are symptoms of the documented UTI (N39.0). Assigning N32.81 simultaneously with N39.0 when the frequency/urgency is integral to the infection would violate the Excludes 1 note. A CDI query is appropriate to ask whether the OAB is a separate, independently diagnosed condition that exists independently of the current UTI, or whether the urgency/frequency is attributable to the infection alone.

Query Response — Option A: Provider responds: “The OAB is a pre-existing, separately documented condition managed independently of the current UTI. The patient has a prior workup confirming OAB.” Corrected Coding (Option A):

• N32.81 — Overactive bladder (separately documented, independent of UTI)
• N39.0 — Urinary tract infection, site not specified (acute current infection)

Query Response — Option B: Provider responds: “The urgency and frequency are due to the current UTI — no independent OAB diagnosis at this time.” Corrected Coding (Option B):

• N39.0 — Urinary tract infection only (N32.81 not assigned — Excludes 1 applies)

---

⚠️ Coding Pitfalls and Tips

	Pitfall or Tip
❌	Coding N32.81 When Urinary Frequency Is Due to Another Documented Bladder Condition. The Excludes 1 note at the N32 category level is absolute — if urgency or frequency is a symptom of cystitis (N30.00), BPH with LUTS (N40.1), bladder calculus (N21.0), or another documented specific condition, code that condition. N32.81 must not be coded for frequency/urgency that is integral to another bladder condition.
❌	Coding N32.81 When N31.0 Is More Appropriate. Overactive bladder (N32.81) is idiopathic/non-neurogenic. When the detrusor overactivity is driven by a documented neurological condition (stroke, Parkinson’s, MS supraspinal), N31.0 (uninhibited neuropathic bladder, NEC) is clinically more accurate. Using N32.81 for neurogenic detrusor overactivity obscures etiology and may affect medical necessity documentation for certain payer criteria.
❌	Billing 52000 Alongside 52287 on the Same Date. CPT 52000 (cystourethroscopy, separate procedure) is bundled into 52287 (cystourethroscopy with Botox injection) — the cystoscopic component is included in 52287. Separately billing 52000 on the same date as 52287 violates NCCI edits and will be denied.
❌	Assigning R39.15 After OAB Is Confirmed. Once the provider has documented “overactive bladder” as a diagnosis, R39.15 (urinary urgency) is a symptom code that is subsumed by the confirmed diagnosis. Do not code both R39.15 and N32.81 simultaneously.
✅	Always Code the Incontinence Separately When OAB Is Wet. N32.81 captures the OAB syndrome; it does NOT capture the incontinence. When urge incontinence is documented alongside OAB, always separately code N39.41 (urge incontinence) or N39.46 (mixed incontinence). Both codes together tell the complete clinical story and strengthen medical necessity for advanced treatments.
✅	Document Failed Prior Treatment Before Billing Third-Line Therapies. For Botox (52287), PTNS (64566), and SNS (64561/64581), payers require documentation of failed conservative and pharmacologic management. The chart must reflect trial and failure of behavioral therapy AND at least one OAB medication before third-line CPT codes will be paid. N32.81 alone is not sufficient — the narrative must support it.
✅	Use Modifier -25 When Billing E/M and Procedure Same Date. When an office visit (99213, 99214) is billed on the same date as urodynamic testing or a minor urologic procedure, Modifier -25 is required on the E/M to demonstrate a separately identifiable and documented medical decision-making service beyond the pre-procedure assessment.
✅	N32.81 Is a Covered Diagnosis for Urodynamics (LCD L35439) and SNS/PTNS (LCD L36809). When submitting claims for urodynamic studies or neuromodulation therapies, N32.81 is listed as a supported covered diagnosis in the relevant CMS LCDs. Place it prominently as the primary diagnosis code on the claim to maximize clean claims rate.

---

📚 Sources

1. CMS/NCHS. ICD-10-CM Official Guidelines for Coding and Reporting, FY2026. Section I.C.14 — Diseases of the genitourinary system; Excludes 1 conventions at N32 category; symptom vs. confirmed diagnosis coding guidance. ^[1]

2. CMS. IPPS Final Rule FY2026 — MS-DRG Definitions Manual v43.0/v43.1. MDC 11 logic tables; DRG 673-675, 698-700 relative weights. ^[2]

3. CMS. ICD-10-CM/PCS MS-DRG v37.2 and v43.0 Definitions Manual — MDC 11 Principal Diagnosis List. Confirms N32.81 groups to DRG 698/699/700 (Other Kidney and Urinary Tract Diagnoses) as principal diagnosis. ^[3]

4. AAPC Codify. ICD-10 Code N32.81 — Overactive Bladder. Code descriptor, Excludes 1 note, Includes term (detrusor muscle hyperactivity), valid FY2026 status. ^[4]

5. icdlist.com. 2026 ICD-10-CM Diagnosis Code N32.81 — Overactive Bladder. Billability confirmation, chronic condition indicator, DRG assignment. ^[5]

6. PROMBS Medical Billing. “Master ICD-10 Code for Overactive Bladder — N32.81.” Published July 2025. Clinical documentation requirements, CPT associations, and billing guidance for OAB. ^[6]

7. MD Clarity. “ICD Diagnosis Code N32.81: What It Is & When to Use.” Published October 2024. Diagnostic criteria, associated CPT codes (52287, 64561, 64581, 64590, 51741, 51784), and clinical documentation framework for N32.81. ^[7]

8. AAPC Urology Coding Alert. “Botox for Bladder Spasms Leads to a Specific CPT Code.” Published October 2018. CPT 52287 coding and bundling guidance, J0585 drug billing, N32.81 as supported diagnosis. ^[8]

9. Boston Scientific. 2026 Coding and Payment Guide — Sacral Neuromodulation (SNM). N32.81 listed as covered OAB diagnosis for SNS (64561, 64581, 64590) prior authorization and billing. ^[9]

10. Elitone / Urinary Incontinence ICD-10. “Urinary Incontinence ICD-10 — Which Code Do I Use?” Published 2021. N32.81 (OAB-dry) vs. N39.41 (urge incontinence/OAB-wet) code selection guidance. ^[10]

11. CMS Medicare Coverage Database. Article A56802 — Billing and Coding: Urodynamics (LCD L35439). N32.81 listed as covered diagnosis for urodynamic studies (51726-51741, 51784-51797). ^[11]

12. Anthem/ABCBS. CG-SURG-95 — Sacral Nerve Stimulation for Urinary Retention and Urinary Incontinence. Updated April 2025. Third-line OAB treatment criteria, N32.81 as qualifying diagnosis, documentation requirements for failed prior treatment. ^[12]