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G25.81

Properties3
codeG25.81
code_titleRestless legs syndrome
statusActive ✅

23 min read

🧬 ICD-10 CM G25.81 — Restless Legs Syndrome

Billable Code Confirmed

ICD-10 CM G25.81 is a fully specified 6-character ICD-10-CM code representing Restless Legs Syndrome (RLS), also known as Willis-Ekbom disease, and requires no additional characters for FY2026 reporting. The code hierarchy runs G25 (category) → G25.8 (subcategory: other specified) → G25.81 (restless legs syndrome specifically), with G25.81 being the only valid terminal code for this diagnosis. This code is complete, billable, and appropriate for both principal and additional diagnosis reporting when RLS is documented by the treating or consulting provider.

Non-Billable Parent Codes

G25 (Other extrapyramidal and movement disorders) is a 3-character category header that is never independently billable; any claim submission using G25 alone will generate a coding edit or claim rejection. G25.8 (Other specified extrapyramidal and movement disorders) is a 5-character subcategory header that remains non-billable due to insufficient specificity, requiring a 6th character to identify the precise condition — submitting G25.8 when G25.81 is clearly supported constitutes an undercoding error. Coders must always carry specificity to the highest documented level; truncating to a parent code in the inpatient setting violates ICD-10-CM Official Guidelines and UHDDS principles.

Clinical Context

RLS is distinguished from all other movement disorders by four IRLSSG-defined criteria: (1) an irresistible urge to move the legs, (2) provocation or worsening at rest, (3) partial or full relief with movement, and (4) characteristic circadian worsening in the evening and night.¹ The critical distinction from periodic limb movement disorder (G47.61) is that RLS is a waking, sensory-driven, consciously experienced symptom, whereas PLMD manifests as rhythmic limb jerks during sleep, typically without the patient’s awareness. CDI teams and coders must ensure the provider has explicitly documented RLS as a clinical diagnosis — symptom language such as “leg restlessness” or “can’t keep legs still” is insufficient for code assignment.

Code Classification

ICD-10 CM G25.81 is a diagnosis code (ICD-10-CM) classifying a chronic neurological and sensorimotor disorder. It is never interchangeable with CPT, HCPCS Level II, or ICD-10-PCS procedure codes, and must not be confused with drug-induced movement disorder codes in the G25.7x subcategory.

🔍 Code Description

Restless legs syndrome, classified under G25.81, is a chronic sensorimotor neurological disorder defined by the four IRLSSG consensus diagnostic criteria and driven by central dopaminergic dysfunction — particularly within the spinal cord and basal ganglia — compounded by iron dysregulation in the central nervous system.¹² Low cerebrospinal fluid ferritin has been documented even in RLS patients with normal serum ferritin levels, underscoring that systemic iron studies alone do not rule out CNS iron deficiency as a contributing mechanism.² RLS presents in two broad forms: idiopathic (primary, often with familial clustering and genetic underpinning) and secondary (symptomatic), with secondary forms associated with iron deficiency anemia (D50.9), end-stage renal disease (N18.6), peripheral neuropathy (G60.9), and pregnancy.³ The condition carries significant morbidity including sleep-onset insomnia, daytime fatigue, anxiety, depression, and impaired functional performance — all of which are directly relevant to inpatient course and length of stay.⁴

From an inpatient coding perspective, G25.81 is most commonly reported as a secondary or additional diagnosis rather than the principal diagnosis driving admission.⁵ In Physical Medicine and Rehabilitation settings, undertreated RLS impairs patient participation in PT and OT sessions, disrupts sleep-dependent neuroplasticity and recovery, and may prolong acute rehabilitation length of stay — all of which justify its reporting as a UHDDS-qualifying additional diagnosis when documented and actively managed.⁶ Active pharmacologic management in the inpatient setting typically includes dopamine agonists (pramipexole, ropinirole), alpha-2-delta calcium channel ligands (gabapentin enacarbil, pregabalin), and IV iron infusion in confirmed iron-deficient patients, any of which support G25.81 as an actively treated condition meeting UHDDS reporting criteria.⁵ For Crystal’s OTO and urology coder counterparts: RLS is a clinically relevant secondary finding in patients with uremia (N18.6) or receiving head/neck radiation with resultant anemia, warranting query when leg restlessness language appears in the record without a named diagnosis.

🌳 Code Tree / Hierarchy

G25 Other extrapyramidal and movement disorders ❌ Non-billable
│
├── G25.0 Essential tremor ✅ Billable
├── G25.1 Drug-induced tremor ✅ Billable
├── G25.2 Other specified forms of tremor ✅ Billable
├── G25.3 Myoclonus ✅ Billable
├── G25.4 Drug-induced chorea ✅ Billable
├── G25.5 Other chorea ✅ Billable
│
├── G25.6 Drug-induced tics and other tics of organic origin ❌ Non-billable
│   │
│   ├── G25.61 Drug induced tics ✅ Billable
│   └── G25.69 Other tics of organic origin ✅ Billable
│
├── G25.7 Other and unspecified drug induced movement disorders ❌ Non-billable
│   │
│   ├── G25.70 Drug induced movement disorder, unspecified ✅ Billable
│   ├── G25.71 Drug induced akathisia ✅ Billable
│   └── G25.79 Other drug induced movement disorders ✅ Billable
│
├── G25.8 Other specified extrapyramidal and movement disorders ❌ Non-billable
│   │
│   ├── G25.81 Restless legs syndrome ◀ THIS CODE ✅ Billable
│   ├── G25.82 Stiff-man syndrome ✅ Billable
│   ├── G25.83 Benign shuddering attacks ✅ Billable
│   └── G25.89 Other specified extrapyramidal and movement disorders ✅ Billable
│
└── G25.9 Extrapyramidal and movement disorder, unspecified ✅ Billable

Specificity Matters: G25.81 vs. G25.89

When the provider has documented restless legs syndrome, Willis-Ekbom disease, or any recognized equivalent clinical term, G25.81 is mandatory — defaulting to G25.89 (Other specified extrapyramidal and movement disorders) constitutes an undercoding error and may trigger a payer specificity audit or coding quality flag. G25.89 is reserved strictly for extrapyramidal or movement disorders that are explicitly named by the provider but do not map to any existing specific ICD-10-CM code.

Tip

The G25.8 subcategory contains exactly four billable codes: G25.81, G25.82, G25.83, and G25.89. When reviewing a chart with documented RLS, stiff-man syndrome, or benign shuddering attacks, always go directly to the specific code — the “other specified” bucket (G25.89) should never be used when a more precise code exists and is supported by documentation.

✅ Includes

ICD-10 CM G25.81 encompasses both primary (idiopathic) and secondary (symptomatic) RLS, provided the provider has explicitly named the diagnosis. Clinical terms documented in the provider’s note that map to G25.81 include: Restless legs syndrome, Willis-Ekbom disease (WED), Ekbom syndrome when referencing the sensorimotor RLS presentation, and nocturnal leg restlessness explicitly diagnosed as RLS. When RLS is secondary to a known cause such as iron deficiency (D50.9) or ESRD (N18.6), code both the underlying cause and G25.81 per ICD-10-CM causal coding conventions applicable to the encounter.

❌ Excludes

Excludes 1

No Excludes 1 notes are present at the G25.81 code level in FY2026. The parent category G25 does not carry Excludes 1 restrictions that directly block use of G25.81. Coders should verify the current FY tabular list annually, as addenda may introduce new exclusion notes in subsequent fiscal year updates.

Danger

Do not assign G25.81 and G25.71 (Drug-induced akathisia) simultaneously for the same clinical presentation of motor or sensory restlessness — these codes represent distinct etiologies and are mutually exclusive for a single documented manifestation. Drug-induced akathisia is driven by dopamine-blocking or dopamine-depleting agents (antipsychotics, metoclopramide, prochlorperazine) and lacks the hallmark circadian and sensory features of RLS; when a consulting neurologist or attending has explicitly differentiated the two, the coder must follow the documented diagnosis and not apply both codes.

Excludes 2

ICD-10 CM G47.61 — Periodic Limb Movement Disorder. PLMD and RLS frequently co-occur and may be coded simultaneously when both conditions are independently documented as active by the provider. PLMD is characterized by repetitive, stereotyped limb movements during NREM sleep captured on polysomnography — typically without the patient’s conscious awareness — while RLS is the waking, sensory-driven urge to move that the patient experiences and reports; they are clinically and etiologically distinct entities that can coexist in the same patient.

📋 Clinical Overview

Accurate clinical differentiation between RLS, periodic limb movement disorder, and drug-induced akathisia is a frequent CDI and inpatient coding challenge because clinicians may use imprecise or overlapping language in the medical record.⁶ The ICD-10-CM Official Guidelines prohibit coder interpretation of symptoms as diagnoses, making it imperative that the provider’s explicit diagnosis — not the symptom description — drives code selection. Understanding the distinguishing clinical features of each condition enables CDI specialists to construct compliant, AHIMA/ACDIS-concordant physician queries when documentation is ambiguous.⁷

FeatureG25.81 RLSG47.61 PLMDG25.71 Drug-Induced Akathisia
Sensory ComponentCore feature — uncomfortable urge to move, often with crawling, creeping, or pulling sensations in the legs; patient is fully conscious of symptomsAbsent — limb movements occur during NREM sleep without patient sensory awareness; patient may be completely unawareAbsent or minimal — restlessness is predominantly motor and anxiety-driven with inner subjective tension but no leg-specific sensory dysesthesia
TimingStrictly circadian — worsens in the evening and nighttime; provoked by rest and relieved by movementNocturnal — occurs during NREM sleep stages; not rest-provoked in the waking sense; identified on polysomnographyNon-circadian — present throughout the day and not specifically tied to rest or time of day
EtiologyIdiopathic (genetic, dopaminergic) or secondary to iron deficiency, CKD, pregnancy, peripheral neuropathyOften co-occurs with RLS; also associated with dopamine-blocking medications and SSRIsCaused by dopamine-blocking or dopamine-depleting agents: antipsychotics, metoclopramide, prochlorperazine, ondansetron
Inpatient TreatmentDopamine agonists (pramipexole, ropinirole), alpha-2-delta ligands (gabapentin enacarbil, pregabalin), IV iron if iron-deficientClonazepam; dopamine agonists when co-occurring RLS is present; address underlying medication triggersDiscontinuation or dose reduction of offending agent; propranolol, clonazepam, or diphenhydramine
Coding RelevanceCommon PM&R, renal, and neurology additional diagnosis; disrupts rehab participation and LOSOften uncovered on polysomnography; may qualify as a separately reportable additional diagnosis alongside G25.81Common in surgical, oncology, and GI inpatients on antidopaminergic agents; requires the offending drug’s adverse effect T-code

Important

A CDI query is warranted when provider documentation contains only symptom language — “leg restlessness,” “can’t keep legs still at night,” “fidgety legs” — without naming a diagnosis. These are signs and symptoms, not conditions, and ICD-10-CM guideline Section I.B prohibits coding them when a definitive diagnosis has been established elsewhere; equally, they cannot be elevated to G25.81 without a provider-documented clinical diagnosis. Per AHIMA and ACDIS query guidance, a non-leading query asking the provider to clarify the clinical impression of the documented leg restlessness is appropriate and compliant.⁷

Manifestations & Symptom Burden

Sensory Dysesthesia: The signature discomfort of RLS — described as crawling, creeping, itching, pulling, aching, or electric sensations in the legs — is not classically painful but is intensely distressing and produces an irresistible urge to move; detailed provider documentation of this feature is what separates RLS from nonspecific leg discomfort.⁸

Sleep-Onset Insomnia and Fragmented Sleep Architecture: RLS is one of the leading neurological causes of chronic sleep-onset insomnia; when inpatient sleep disruption is explicitly attributed to RLS by the provider, it supports medical necessity documentation and coding of G47.00 (Insomnia, unspecified) as an additional diagnosis if separately documented.⁹

Augmentation Syndrome: A paradoxical worsening of RLS symptoms with long-term dopaminergic therapy — occurring earlier in the day, spreading to the arms, and increasing in intensity — that may necessitate medication switches, dosage adjustments, or inpatient pharmacologic management and should be documented as an active complication by the treating physician.¹⁰

Psychiatric Comorbidity Burden: RLS is associated with significantly elevated rates of F41.1 (Generalized anxiety disorder) and F32.9 (Major depressive disorder, single episode, unspecified); when independently documented and clinically managed, these should be coded as additional diagnoses and may qualify as CCs depending on the **MS-DRG grouper.**¹¹

Functional Impairment: In the rehabilitation setting, RLS-driven sleep deprivation and nocturnal leg discomfort directly impair therapy participation, cognitive engagement, and motor learning — clinical documentation of this functional impact by the PM&R attending is what elevates G25.81 from an incidental finding to a UHDDS-qualifying additional diagnosis.⁶

Tip

When RLS is documented in the context of ESRD or advanced CKD (N18.6, N18.5, N18.4), always code both the renal condition and G25.81 — uremic RLS is the most severe secondary form and is frequently undertreated and underdocumented in dialysis-adjacent inpatient units. Per ICD-10-CM causal coding conventions, sequence the underlying renal condition according to the reason for admission; G25.81 reports as an additional diagnosis reflecting active comorbidity. CDI teams embedded in nephrology, transplant, or urology services should maintain a high index of suspicion for RLS in any patient with advanced renal impairment and leg discomfort documentation.

💰 HCC Risk Adjustment

FieldDetail
HCC Mapping (V28)Not HCC-Mapped
CMS-HCC ModelV28 (Effective 2024)
RAF Score Contribution0.000 — No direct RAF contribution
Annual Recapture RequiredNo
Key Co-Occurring HCC-Eligible CodesN18.3 (HCC 329), N18.4 (HCC 329), N18.5 (HCC 330), N18.6 (HCC 329), G60.9 (verify mapping)

ICD-10 CM G25.81 generates no RAF score under CMS-HCC Model V28 and is not subject to annual recapture requirements for Medicare Advantage risk adjustment purposes.¹² The risk adjustment value of accurately documenting G25.81 is entirely indirect: it creates a clinical audit trail that prompts coders and CDI specialists to verify that the underlying and co-occurring HCC-eligible conditions — particularly CKD stages 3-5 and ESRD — are coded with full specificity.¹³ Payers including UHC, Aetna, Cigna, BCBS of WI, and Medicare Advantage plans do not weight G25.81 for reimbursement, but missing the nephropathy, iron deficiency anemia, or peripheral neuropathy driving secondary RLS represents a genuine and auditable revenue integrity gap. Documentation improvement focused on RLS should always cascade to a comorbidity capture review of the full problem list.

🏥 MS-DRG Assignment

ScenarioDRGTitle
G25.81 as PDx + qualifying MCC091Other Disorders of Nervous System with MCC
G25.81 as PDx + qualifying CC092Other Disorders of Nervous System with CC
G25.81 as PDx, no CC/MCC093Other Disorders of Nervous System without CC/MCC

When sequenced as the principal diagnosis, G25.81 groups to MDC 01 (Diseases and Disorders of the Nervous System) and resolves to DRG 091, 092, or 093 based on the presence and severity of qualifying secondary diagnoses meeting CC or MCC criteria under the MS-DRG v41 definitions.¹⁴ G25.81 itself holds no CC or MCC designation and adds no DRG weight when coded as a secondary diagnosis.¹⁵ Standalone inpatient admissions with G25.81 as the principal diagnosis are uncommon and will face medical necessity challenges from Medicare, Wisconsin Medicaid, and commercial payers including UMR and Aetna; documentation must establish why the severity of the condition required hospital-level care rather than outpatient or observation management. In practice, the most common and defensible inpatient scenario is G25.81 as an additional diagnosis during admissions for CKD/ESRD management, post-surgical recovery, or acute rehabilitation — where the coding value lies in clinical completeness and UHDDS compliance rather than direct DRG impact.¹⁶ When a secondary diagnosis such as D50.9 (iron deficiency anemia) or N18.6 (ESRD) carries CC weight, it can shift the grouper from DRG 093 to DRG 092 with meaningful reimbursement implications.

🔗 Related ICD-10-CM Codes

Closely Related Movement and Sleep-Related Disorders:

  • G47.61 — Periodic limb movement disorder (PLMD; may co-occur and be coded concurrently with G25.81 when both documented)
  • G25.71 — Drug-induced akathisia (clinical mimicker; distinct etiology — do not code with G25.81 for same presentation)
  • G25.82 — Stiff-man syndrome (sibling code within G25.8 subcategory)
  • G25.89 — Other specified extrapyramidal and movement disorders (use only when no specific code applies)
  • G25.9 — Extrapyramidal and movement disorder, unspecified (last resort — only when no specificity is documented)
  • G47.00 — Insomnia, unspecified (RLS-driven insomnia; code separately only when independently documented by the provider)
  • G60.9 — Hereditary and idiopathic neuropathy, unspecified (peripheral neuropathy as secondary RLS trigger)

Common Underlying and Co-Occurring Conditions:

  • N18.6 — End-stage renal disease (uremic RLS — most severe and prevalent secondary form)
  • N18.5 — Chronic kidney disease, stage 5 (pre-dialysis severe CKD associated with RLS)
  • N18.4 — Chronic kidney disease, stage 4 (moderate-to-severe CKD; common RLS trigger)
  • D50.9 — Iron-deficiency anemia, unspecified (primary secondary cause of RLS; IV iron is a targeted inpatient treatment)
  • Z99.2 — Dependence on renal dialysis (hemodialysis-dependent patients carry high RLS prevalence)
  • F41.1 — Generalized anxiety disorder (high psychiatric comorbidity in RLS; may qualify as a CC)
  • F32.9 — Major depressive disorder, single episode, unspecified (elevated depressive comorbidity in RLS)

🛠️ Commonly Associated CPT Codes

95810 — Polysomnography, age 6 years or older; sleep staging with 4 or more additional parameters of sleep, attended by a technologist.¹⁷ This is the primary diagnostic sleep study used to evaluate sleep architecture fragmentation and to identify co-occurring PLMD in RLS patients; inpatient polysomnography is billable under the professional component when ordered and interpreted by a qualifying provider or sleep medicine consultant. When both G25.81 and G47.61 are being evaluated concurrently, 95810 is the appropriate comprehensive polysomnography CPT.

95811 — Polysomnography, age 6 years or older; sleep staging with 4 or more additional parameters of sleep, with initiation of continuous positive airway pressure (CPAP) therapy or bilevel ventilation.¹⁸ In inpatients where RLS co-occurs with obstructive sleep apnea (G47.33), a CPAP titration study may be ordered alongside RLS evaluation; this CPT is commonly encountered in PM&R and pulmonary medicine consultations when both conditions are concurrently identified and require separate management.

99233 — Subsequent hospital inpatient or observation care, per day; high complexity medical decision making.¹⁹ Daily attending or consultant visits documenting active RLS management — dopaminergic medication adjustment, monitoring for augmentation syndrome, or IV iron infusion oversight — support subsequent visit E/M coding; ensure documentation reflects the complexity of MDM rather than defaulting to lowest-level coding, as undertreated RLS in a rehabilitation context frequently meets moderate-to-high MDM thresholds.

96372 — Therapeutic, prophylactic, or diagnostic injection (specify substance or drug); subcutaneous or intramuscular.²⁰ IM administration of iron dextran or other IM iron formulations for RLS-associated iron deficiency may be reported with this code alongside the appropriate J-code for the specific iron product; IV iron infusion would instead be captured under the applicable infusion CPT codes (96365-96368) and J-codes.

90867 — Therapeutic repetitive transcranial magnetic stimulation (TMS) treatment; initial, including cortical mapping, motor threshold determination, delivery and management.²¹ Emerging evidence supports repetitive TMS for treatment-refractory RLS; when ordered and performed by a qualified provider during an inpatient stay, documentation must establish provider qualification, medical necessity, and a separate, identifiable service supporting this CPT.

NCCI Bundling Considerations

CPT 95810 and 95811 are mutually exclusive on the same date of service for the same patient — a full-night diagnostic polysomnography and a CPAP titration study cannot be billed together for a single night’s study; two separate nights of testing are required to bill both.²² Any E/M service such as 99233 performed on the same date as a diagnostic procedure like 95810 requires either documentation establishing a separately identifiable service or modifier -25 appended to the E/M code; the E/M must not be incidental to the procedure.²³

🔬 ICD-10-PCS Crosswalk

3E03329 — Introduction, Peripheral Vein, Percutaneous, Other Therapeutic Substance. When IV iron infusion (iron sucrose, ferric carboxymaltose, low molecular weight iron dextran) is administered for iron-deficiency-driven secondary RLS, this ICD-10-PCS code captures the intravenous introduction procedure; the operative/nursing documentation and MAR should specify the iron product and route to support the root operation “Introduction” and the substance character “Other Therapeutic Substance.”²⁴

GZF1ZZZ — Therapeutic Repetitive Transcranial Magnetic Stimulation (rTMS). For refractory RLS patients undergoing TMS during an inpatient neurologic or PM&R stay, this ICD-10-PCS code within the Mental Health section captures the therapeutic application; attending documentation must support the indication, treatment parameters, and clinical rationale for inpatient-level TMS administration.²⁵

HZ2ZZZZ — Detoxification Services. In rare cases where RLS augmentation from long-term opioid use — prescribed as a refractory RLS treatment — has progressed to opioid dependence requiring structured inpatient detoxification, this PCS code may apply; coder should confirm the clinical documentation explicitly establishes detoxification as a distinct, planned inpatient service.²⁶

F07Z8ZZ — Motor Treatment, Neurological System and Cranial Nerves, None Qualifier. Physical rehabilitation targeting gait, mobility, and functional performance in PM&R inpatients where RLS-related deconditioning or sleep deprivation has impaired motor function may be captured under rehabilitation section PCS codes; defer to the therapist’s treatment documentation for the precise body part and qualifier characters.²⁷

💊 Coding Scenarios and Examples

Scenario 1: Secondary RLS in a Dialysis-Dependent ESRD Patient A 67-year-old male with ESRD on hemodialysis (N18.6, Z99.2) is admitted for management of worsening RLS refractory to pramipexole, causing severe sleep disruption and fatigue. The attending nephrologist documents RLS as an active complicating condition, initiates IV iron sucrose for documented iron deficiency, and adjusts the dopaminergic regimen. The admission is driven by the ESRD and RLS management; iron deficiency anemia is confirmed by labs and documented.

  • PDx: N18.6 (ESRD — primary reason for admission and management)
  • Additional: G25.81, Z99.2, D50.9
  • Sequencing: ESRD sequences as PDx as it is the primary condition requiring hospitalization; G25.81 meets UHDDS criteria as an actively managed, clinically significant additional diagnosis; D50.9 supports IV iron administration and may qualify as a CC affecting DRG assignment.
  • CDI Note: Ensure the attending’s note explicitly documents RLS as an active diagnosis being treated — the IV iron order and administration record alone do not support G25.81without a documented clinical diagnosis in the physician’s note.

Scenario 2: RLS Complicating Acute Inpatient Rehabilitation A 54-year-old female admitted to acute inpatient rehabilitation following lumbar spinal cord injury (S34.101A) develops significantly worsening RLS symptoms that the PM&R attending documents as a primary barrier to therapy participation, limiting PT and OT session duration. Gabapentin enacarbil is initiated and the PM&R note states RLS is being actively managed as a complicating condition affecting the rehabilitation course.

  • PDx: S34.101A (lumbar SCI — primary reason for rehabilitation admission)
  • Additional: G25.81
  • Sequencing: The SCI code drives the MDC and DRG assignment; G25.81 qualifies as a reportable additional diagnosis per UHDDS because it is documented and actively treated by the attending during the encounter.
  • CDI Note: PM&R documentation must explicitly state that RLS is clinically significant, is being actively managed, and is impacting the functional rehabilitation course — without this language, G25.81 may not meet UHDDS criteria as a reportable additional diagnosis.

Scenario 3: RLS Differentiated from Drug-Induced Akathisia A 72-year-old female on metoclopramide for gastroparesis (K31.84) is admitted and develops “inability to sit still, legs feel restless at night.” A consulting neurologist evaluates the patient and documents the presentation as consistent with restless legs syndrome based on the circadian pattern, sensory dysesthesia, and relief with ambulation, explicitly distinguishing it from drug-induced akathisia. The hospitalist documents RLS as an active additional diagnosis per the neurology consult.

  • PDx: K31.84 (gastroparesis — primary reason for admission)
  • Additional: G25.81 (per documented neurologist diagnosis)
  • Do NOT code: G25.71 — Drug-induced akathisia explicitly ruled out by the consulting neurologist
  • Sequencing: Gastroparesis as PDx; G25.81 added as an additional diagnosis per the treating consultant’s explicitly documented clinical impression.
  • CDI Note: When a consulting physician explicitly differentiates RLS from akathisia in a formal consult note, the coder must follow that documented diagnosis — this is a scope-of-practice boundary; coding G25.71 in the face of explicit neurologist documentation of G25.81 constitutes a coding error regardless of the coder’s clinical suspicion.

⚠️ Coding Pitfalls and Tips

  1. Never submit G25 or G25.8 as billable codes. Both are non-billable parent codes that will generate claim edits. G25.81 requires all six characters to be valid; truncating to the category or subcategory level is a compliance and revenue integrity error.

  2. “Leg restlessness” is not G25.81. ICD-10-CM Official Guidelines Section I.B require a definitive provider-documented diagnosis for code assignment; symptom descriptors (“leg restlessness,” “fidgety legs,” “can’t keep legs still”) without a named diagnosis do not support G25.81 and should trigger a compliant CDI query.

  3. Do not code G25.81 and G25.71 simultaneously for the same presenting complaint. Drug-induced akathisia and RLS are distinct diagnoses with different etiologies, treatments, and codes; assigning both for a single undifferentiated presentation of restlessness is a coding error. Query the provider for clarification when documentation does not make the distinction clear.

  4. Secondary RLS requires dual coding. When the provider has documented RLS as secondary to a known etiology — iron deficiency (D50.9), ESRD (N18.6), peripheral neuropathy (G60.9) — code both the underlying condition and G25.81. ICD-10-CM does not impose mandatory etiology/manifestation sequencing for G25.81 specifically, so sequence based on the reason for the encounter per UHDDS and Official Guidelines.

  5. G25.81 is not a CC or MCC. It generates no DRG weight uplift as a secondary diagnosis. The value of coding it accurately is UHDDS compliance, clinical accuracy, and serving as a trigger to capture co-occurring HCC-eligible and CC/MCC-eligible comorbidities that do carry DRG weight.

  6. Augmentation syndrome from dopaminergic RLS therapy is not a separate ICD-10-CM code in FY2026. Document and code it as G25.81 (the underlying RLS) with the appropriate adverse effect T-code for the causative dopaminergic medication (e.g., T42.8X5A for adverse effect of antiparkinson drugs, initial encounter); the augmentation phenomenon itself does not have a standalone ICD-10-CM code and should not be coded as a new or distinct diagnosis.

📚 Sources

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1. Allen RP, Picchietti DL, Garcia-Borreguero D, et al. Restless legs syndrome/Willis-Ekbom disease diagnostic criteria: updated IRLSSG consensus criteria — history, rationale, description, and significance. *Sleep Medicine*. 2014;15(8):860-873. 2. Earley CJ, Connor J, Garcia-Borreguero D, et al. Altered brain iron homeostasis and dopaminergic function in restless legs syndrome. *Sleep Medicine*. 2014;15(11):1288-1301. 3. Trenkwalder C, Allen R, Högl B, Paulus W, Winkelmann J. Restless legs syndrome associated with major diseases: a systematic review and new concept. *Neurology*. 2016;86(14):1336-1343. 4. Allen RP, Walters AS, Montplaisir J, et al. Restless legs syndrome prevalence and impact: REST general population study. *Archives of Internal Medicine*. 2005;165(11):1286-1292. 5. Winkelman JW, Armstrong MJ, Allen RP, et al. Practice guideline summary: treatment of restless legs syndrome in adults. *Neurology*. 2016;87(24):2585-2593. 6. AHIMA. Clinical Documentation Improvement Toolkit. American Health Information Management Association. Chicago, IL. 2023. 7. AHIMA/ACDIS. Guidelines for Achieving a Compliant Query Practice. 2019 update. Chicago, IL: AHIMA Press. 2019. 8. Earley CJ. Restless legs syndrome. *New England Journal of Medicine*. 2003;348(21):2103-2109. 9. Hornyak M, Feige B, Riemann D, Voderholzer U. Periodic leg movements in sleep and periodic limb movement disorder: prevalence, clinical significance and treatment. *Sleep Medicine Reviews*. 2006;10(3):169-177. 10. Garcia-Borreguero D, Silber MH, Winkelman JW, et al. Guidelines for the first-line treatment of restless legs syndrome/Willis-Ekbom disease, prevention and treatment of dopaminergic augmentation: a combined task force of the IRLSSG, EURLSSG, and the RLS-foundation. *Sleep Medicine*. 2016;21:1-11. 11. Hornyak M. Depressive disorders in restless legs syndrome: epidemiology, pathophysiology, and management. *CNS Drugs*. 2010;24(2):89-98. 12. Centers for Medicare and Medicaid Services. CMS-HCC Risk Adjustment Model V28 — Code Mappings and Documentation. CMS.gov. 2024. https://www.cms.gov/medicare/health-plans/medicareadvtgspecratestats/risk-adjustors 13. Centers for Medicare and Medicaid Services. Medicare Advantage Risk Adjustment. 2025. https://www.cms.gov/medicare/health-plans/medicareadvtgspecratestats/risk-adjustors 14. Centers for Medicare and Medicaid Services. MS-DRG Definitions Manual v41.0. FY2024. https://www.cms.gov/icd10m/version41-fullcode-cms 15. Centers for Medicare and Medicaid Services. MS-DRG Version 41 CC/MCC Exclusions List. FY2024. https://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/AcuteInpatientPPS 16. AAPC. Inpatient Facility Coding and Billing — DRG Logic and Sequencing Reference. 2024. https://www.aapc.com 17. American Medical Association. CPT Professional Edition 2026. Chicago, IL: AMA Press. 2025. 18. American Medical Association. CPT Professional Edition 2026. Chicago, IL: AMA Press. 2025. 19. American Medical Association. CPT Professional Edition 2026. Chicago, IL: AMA Press. 2025. 20. American Medical Association. CPT Professional Edition 2026. Chicago, IL: AMA Press. 2025. 21. American Medical Association. CPT Professional Edition 2026. Chicago, IL: AMA Press. 2025. 22. Centers for Medicare and Medicaid Services. National Correct Coding Initiative (NCCI) Policy Manual for Medicare Services, Chapter 9: Evaluation and Management. FY2025. https://www.cms.gov/Medicare/Coding/NationalCorrectCodInitEd 23. Centers for Medicare and Medicaid Services. NCCI Procedure-to-Procedure Edit Files. FY2025. https://www.cms.gov/Medicare/Coding/NationalCorrectCodInitEd/NCCI-Policy-Manual 24. Centers for Medicare and Medicaid Services. ICD-10-PCS Reference Manual FY2026. https://www.cms.gov/Medicare/Coding/ICD10/2026-ICD-10-PCS.html 25. Centers for Medicare and Medicaid Services. ICD-10-PCS Reference Manual FY2026. https://www.cms.gov/Medicare/Coding/ICD10/2026-ICD-10-PCS.html 26. Centers for Medicare and Medicaid Services. ICD-10-PCS Reference Manual FY2026. https://www.cms.gov/Medicare/Coding/ICD10/2026-ICD-10-PCS.html 27. Centers for Medicare and Medicaid Services. ICD-10-PCS Reference Manual FY2026. https://www.cms.gov/Medicare/Coding/ICD10/2026-ICD-10-PCS.html

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