ICD-10-PCS Body Part Index & Root Operation Reference

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Part 1 — Body Part Index (Character 4)

How to use this table

When a clinical or anatomical term in the operative note does not appear as a body part value in the PCS table, look it up here. The “Maps To” column is your Character 4 value.

Eye

Clinical / Anatomical Term	Maps To (PCS Body Part)	Notes
Bruch’s membrane	Choroid, Left / Right	Sub-layer of retina
Ciliary zonule	Eye, Left / Right	Also called zonule of Zinn
Zonule of Zinn	Eye, Left / Right	Suspensory ligament of lens
Lacrimal punctum	Lacrimal Duct, Left / Right	Opening of lacrimal drainage
Uvea	Uvea, Left / Right	Iris + ciliary body + choroid
Schlemm’s canal	Sclera, Left / Right	Trabecular drainage channel
Trabecular meshwork	Eye, Left / Right	Aqueous outflow structure
Fovea centralis	Retina, Left / Right	Central retinal depression
Optic disc	Retina, Left / Right	Optic nerve head

Ear / Nose / Sinus

Clinical / Anatomical Term	Maps To (PCS Body Part)	Notes
Cochlea	Inner Ear, Left / Right	Auditory sensory organ
Semicircular canals	Inner Ear, Left / Right	Vestibular equilibrium
Ossicular chain	Auditory Ossicle, Left / Right	Malleus / incus / stapes
Eustachian tube	Auditory Tube, Left / Right	Connects middle ear to pharynx
Tympanic membrane	Tympanic Membrane, Left / Right	Eardrum — has own value
Mastoid air cells	Mastoid Sinus, Left / Right	Air cells in mastoid process
Adenoids	Nasopharynx	Pharyngeal tonsil tissue
Concha bullosa	Nasal Turbinate	Aerated middle turbinate

Cardiovascular

Clinical / Anatomical Term	Maps To (PCS Body Part)	Notes
Sinoatrial (SA) node	Conduction Mechanism	Primary cardiac pacemaker
Atrioventricular (AV) node	Conduction Mechanism	Secondary conduction node
Bundle of His	Conduction Mechanism	Interventricular conduction
Purkinje fibers	Conduction Mechanism	Terminal conduction fibers
Chordae tendineae	Papillary Muscle	Tendinous cords to valve leaflets
Mitral valve leaflet	Mitral Valve	Bicuspid valve leaflets
Tricuspid annulus	Tricuspid Valve	Fibrous ring of TV
Circle of Willis	Intracranial Artery	Arterial anastomotic circle
Cisterna chyli	Thoracic Duct	Lymphatic cistern at L2

Respiratory

Clinical / Anatomical Term	Maps To (PCS Body Part)	Notes
Arytenoid cartilage	Larynx	Paired cartilages of larynx
Cricoid cartilage	Larynx	Ring cartilage inferior larynx
Thyroid cartilage	Larynx	Largest laryngeal cartilage
Glottis	Larynx	Vocal apparatus incl. vocal folds
Carina	Trachea	Bifurcation ridge of trachea

Genitourinary

Clinical / Anatomical Term	Maps To (PCS Body Part)	Notes
Detrusor muscle	Bladder	Smooth muscle of bladder wall
Trigone of bladder	Bladder	Triangular region at bladder base
Ureterovesical junction (UVJ)	Ureter, Left / Right	Distal ureter at bladder entry
Ureteropelvic junction (UPJ)	Kidney Pelvis, Left / Right	Proximal ureter at renal pelvis
Glomerulus	Kidney, Left / Right	Filtration unit of nephron
Bowman’s capsule	Kidney, Left / Right	Glomerular capsule
Renal calyx	Kidney Pelvis, Left / Right	Collecting structures
Prostatic urethra	Urethra	Segment within prostate
Cowper’s gland	Urethra	Bulbourethral gland

Reproductive

Clinical / Anatomical Term	Maps To (PCS Body Part)	Notes
Corpus spongiosum	Penis	Erectile tissue surrounding urethra
Ovarian follicle	Ovary, Left / Right	Included within ovary value
Fallopian tube	Fallopian Tube, Left / Right	Bilateral value also available

Gastrointestinal

Clinical / Anatomical Term	Maps To (PCS Body Part)	Notes
Vermiform appendix	Appendix	Cecal appendage
Pyloric antrum	Stomach, Pylorus	Distal gastric chamber
Ampulla of Vater	Ampulla of Vater	Has its own PCS body part value
Sphincter of Oddi	Hepatobiliary Duct	Controls bile/pancreatic flow
Uvula	Soft Palate	Pendulous soft palate extension
Frenulum linguae	Tongue	Lingual frenum
Dentate line	Anal Sphincter	Pectinate line — transition zone

Nervous System

Clinical / Anatomical Term	Maps To (PCS Body Part)	Notes
Cauda equina	Lumbar Spinal Cord	L2 and below nerve roots
Conus medullaris	Spinal Cord	Terminal segment of spinal cord
Dura mater (spinal)	Spinal Meninges	Outer meningeal layer, spine
Arachnoid mater (cranial)	Cerebral Meninges	Middle cranial meningeal layer
Corpus callosum	Brain	Commissural white matter
Basal ganglia	Basal Ganglia	Has its own PCS body part value

Musculoskeletal

Clinical / Anatomical Term	Maps To (PCS Body Part)	Notes
Rotator cuff	Shoulder Muscle, Left / Right	4-muscle complex
Deltoid muscle	Upper Arm Muscle, Left / Right	Shoulder abductor
Meniscus (knee)	Knee Joint, Left / Right	Fibrocartilage knee pad
Achilles tendon	Lower Leg Tendon, Left / Right	Calcaneal tendon
Plantar fascia	Foot Bursa and Ligament, Left / Right	Plantar aponeurosis
Acetabulum	Acetabulum, Left / Right	Hip socket — has own value

Skin / Breast

Clinical / Anatomical Term	Maps To (PCS Body Part)	Notes
Areola	Nipple, Left / Right	Included within nipple value
Nipple	Nipple, Left / Right	Has its own PCS body part value

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Part 2 — Root Operation Grid (Character 3)

How to use this table

Root operations define what was done. Character 3 is the root operation value. When a question describes a procedure without naming the root op, match the description to the definition below.

CIC Strategy

The exam frequently tests look-alike pairs. See the callout boxes after the table for the most-tested distinctions.

Excision / Destruction Group

Root Operation	Char	Definition	Clinical Examples
Excision	B	Cutting out/off a portion of a body part, no replacement	Biopsy, partial hepatectomy, lumpectomy
Resection	T	Cutting out/off all of a body part, no replacement	Total colectomy, cholecystectomy, total nephrectomy
Destruction	5	Physical eradication using energy, force, or destructive agent	Ablation, fulguration, cryotherapy, laser
Detachment	6	Cutting off all or part of an extremity	Amputation — upper or lower extremity only
Division	8	Cutting into a body part to separate or transect — no drainage	Osteotomy, neurotomy, fasciotomy
Extraction	D	Pulling or stripping out/off all or part of a body part by force	Vein stripping, liposuction, D&C, tooth extraction

Drainage / Extirpation Group

Root Operation	Char	Definition	Clinical Examples
Drainage	9	Taking or letting out fluids and/or gases from a body part	Thoracentesis, paracentesis, abscess I&D
Extirpation	C	Taking or cutting out solid matter from a body part	Thrombectomy, calculus removal, foreign body removal
Fragmentation	F	Breaking solid matter in a body part into pieces	ESWL, lithotripsy, breaking up clots

Repair / Restoration Group

Root Operation	Char	Definition	Clinical Examples
Repair	Q	Restoring a body part to its normal anatomic structure/function	Herniorrhaphy, laceration repair, cleft palate closure
Reattachment	M	Putting back a separated body part to its normal or suitable location	Replantation, reimplantation, severed digit
Release	N	Freeing a body part from abnormal physical constraint by cutting or force	Adhesiolysis, carpal tunnel release, lysis of adhesions
Revision	W	Correcting a malfunctioning or displaced device	Pacemaker lead adjustment, revision arthroplasty

Insertion / Replacement Group

Root Operation	Char	Definition	Clinical Examples
Replacement	R	Putting in material that physically takes the place of all or part of a body part	Total joint arthroplasty, corneal transplant, skin graft
Supplement	U	Putting in material that reinforces or augments a body part that remains	Hernia mesh, annuloplasty ring, tendon graft reinforcement
Insertion	H	Putting in a nonbiological appliance that monitors, assists, or prevents a physiological function	Pacemaker, cardiac monitor, PICC line, drainage device
Change	2	Taking out and putting back an identical or similar device without cutting skin	Drain tube change, cast change, trach tube change
Removal	P	Taking out or off a device from a body part	Hardware removal, explant of pacemaker

Movement / Transfer Group

Root Operation	Char	Definition	Clinical Examples
Bypass	1	Altering the route of passage of contents of a tubular body part	CABG, ileal conduit, gastric bypass
Reposition	S	Moving a body part to its normal or other suitable location	ORIF, reduction of fracture, orchiopexy
Transfer	X	Moving a body part to take over function of another — without taking it out	Local pedicle flap, muscle transfer, tongue flap
Transplantation	Y	Putting in a living body part from another individual or animal	Kidney transplant, liver transplant, heart transplant

Inspection / Map Group

Root Operation	Char	Definition	Clinical Examples
Inspection	J	Visually and/or manually exploring a body part	Diagnostic laparoscopy, arthroscopy, bronchoscopy
Map	K	Locating route of electrical impulses or functional areas	Cardiac electrophysiology mapping, brain functional mapping

Fusion / Fixation Group

Root Operation	Char	Definition	Clinical Examples
Fusion	G	Joining portions of an articular body part rendering it immobile	Spinal fusion, ACDF, arthrodesis

Other Group

Root Operation	Char	Definition	Clinical Examples
Alteration	0	Modifying anatomical structure without affecting function	Rhinoplasty, blepharoplasty, breast augmentation (cosmetic)
Control	3	Stopping or attempting to stop postprocedural or other acute bleeding	Control of hemorrhage, post-op bleed management
Creation	4	Forming a new body part that replicates anatomic structure or function	Sex reassignment constructs, neovagina, neophallus
Dilation	7	Expanding an orifice or lumen of a tubular body part	Balloon dilation, urethral dilation, esophageal dilation
Occlusion	L	Completely closing an orifice or lumen of a tubular body part	Tubal ligation, embolization, vessel ligation
Restriction	V	Partially closing an orifice or lumen of a tubular body part	Lap band, cervical cerclage, esophageal banding

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Part 3 — Root Operation Supplement (U) — Deep Dive

What is Supplement?

Supplement (U) is the root operation used when biological or synthetic material is placed in or on a body part to physically reinforce and/or augment the function of a portion of a body part. Critically, the native body part is not removed or replaced — it remains in place and is being supported or strengthened.

Key Distinguishing Features

Feature	Supplement (U)	Replacement (R)
Native body part status	Remains in place	Removed or rendered non-functional
Material purpose	Reinforce or augment	Take the place of
Body part value	The body part being supplemented	The body part being replaced
Common materials	Mesh, synthetic patch, allograft, autograft (reinforcement)	Prosthesis, implant, cadaveric graft

Supplement vs. Repair

Scenario	Correct Root Op	Rationale
Hernia defect closed with suture only	Repair (Q)	Native tissue only — no supplemental material
Hernia defect closed with mesh reinforcement	Supplement (U)	Synthetic material augments the native repair
Tendon repaired with suture	Repair (Q)	Native tissue approximated
Tendon repair with tendon graft reinforcement	Supplement (U)	Graft material augments — native tendon remains
Valve repair with annuloplasty ring	Supplement (U)	Ring reinforces native valve — valve not replaced
Total valve replacement with prosthesis	Replacement (R)	Native valve removed and replaced

Common Clinical Scenarios for Supplement

Procedure	Body Part Value	Material Type
Inguinal hernia repair with mesh	Inguinal Region, Left / Right	Synthetic
Ventral hernia repair with mesh	Abdominal Wall	Synthetic
Mitral valve annuloplasty with ring	Mitral Valve	Synthetic
Rotator cuff repair with allograft patch	Shoulder Muscle, Left / Right	Nonautologous
Achilles tendon repair with graft	Lower Leg Tendon, Left / Right	Autologous or Nonautologous
Dural patch placement	Dura Mater	Autologous or Synthetic
Bladder sling (urethral support)	Urethra	Synthetic
Breast reconstruction with acellular dermal matrix	Breast, Left / Right	Nonautologous

Character 6 — Device Values Used with Supplement

Device Value	Description	Examples
7 — Autologous Tissue Substitute	From the patient’s own body	Autologous tendon graft, fascia lata
J — Synthetic Substitute	Man-made material	Polypropylene mesh, Gore-Tex patch
K — Nonautologous Tissue Substitute	From donor or cadaver source	Acellular dermal matrix, allograft patch

CIC Pitfall — Supplement vs. Replacement

The single most common Supplement error on the CIC exam is coding a valve annuloplasty ring as Replacement. The native valve leaflets are NOT removed — they remain. The ring reinforces the annulus. This is Supplement, not Replacement. Only code Replacement when the original body part is removed and a new one takes its place.

CIC Pitfall — Supplement + Repair in same session

When a procedure involves both native tissue repair AND mesh/graft reinforcement in the same operative session on the same body part, code only Supplement (U). The Repair is considered integral to the Supplement procedure and is not coded separately.

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Part 4 — Most-Tested Root Operation Pairs

CIC Exam Strategy

These pairs appear frequently because the definitions are close. Nail the distinguishing element for each.

Pair	Key Distinction
Excision vs. Resection	Excision = portion removed; Resection = all of a body part removed
Destruction vs. Excision	Destruction = eradicated in place (no specimen); Excision = cut out (specimen obtained)
Division vs. Drainage	Division = cut to separate (no fluid); Drainage = fluid/gas removed
Extirpation vs. Drainage	Extirpation = solid matter; Drainage = fluid or gas
Repair vs. Supplement	Repair = native tissue only; Supplement = material added to reinforce
Supplement vs. Replacement	Supplement = native part remains; Replacement = native part gone
Release vs. Division	Release = free from abnormal constraint; Division = transect the structure itself
Occlusion vs. Restriction	Occlusion = complete closure; Restriction = partial closure
Bypass vs. Dilation	Bypass = reroutes flow; Dilation = expands existing lumen
Reposition vs. Transfer	Reposition = move to normal/suitable location; Transfer = move to take over function of another part
Inspection vs. Map	Inspection = visual/manual exploration; Map = electrical/functional localization
Insertion vs. Replacement	Insertion = nonbiological appliance, body part stays; Replacement = material takes the place of body part
Change vs. Removal	Change = swap identical/similar device, no incision; Removal = take out device (may require incision)
Transplantation vs. Transfer	Transplantation = living tissue from another individual; Transfer = patient’s own tissue moved

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ICD-10-PCS Body Part Index

Overview

The ICD-10-PCS Body Part Index is a reference tool embedded within the ICD-10-PCS Alphabetic Index that maps anatomical structure names — as used in clinical documentation — to the correct Body Part value (Character 4) in an ICD-10-PCS code. It bridges the gap between surgical and anatomical terminology found in operative notes and the discrete body part characters defined in the PCS tables.

Key Concept

The Body Part Index does not produce a complete code. It directs the coder to the correct table and Character 4 value. Table verification is always required before finalizing the code.

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Purpose and Function

Function	Description
Terminology translation	Converts clinical/surgical anatomical terms to PCS body part values
Body part grouping	Identifies when a sub-structure is included within a broader body part
Table navigation	Points the coder to the correct PCS table section for the body part
Unbundling prevention	Clarifies when two named structures share one body part character
CIC exam readiness	Tests knowledge of anatomy-to-character mapping in exam scenarios

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Where It Lives in the PCS Index

The ICD-10-PCS coding system contains two primary index tools:

Index Tool	Purpose
Alphabetic Index	Look up the procedure/operation to find the root operation and partial code path
Body Part Index (Body Part Key)	Look up an anatomical structure to find the correct Character 4 body part value

Workflow Tip

Start with the Alphabetic Index for the procedure → use the Body Part Index when the anatomical term in the op note does not directly match a body part value in the table.

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Structure of the Body Part Index

Each entry in the Body Part Index contains:

1. Anatomical term — the structure as it may appear in clinical documentation
2. Use statement — identifies the PCS body part value it maps to
3. Body system reference — the character 2 system under which the body part falls

Example Entry Format

Bruch's membrane
    use Choroid, Left
    use Choroid, Right

Detrusor muscle
    use Bladder

Lacrimal punctum
	use Lacrimal Duct, Left
	use Lacrimal Duct, Right

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Character 4 in Context

ICD-10-PCS codes are 7 characters. Character 4 is the Body Part character.

Position	Character	Defines
1	Section	Broad classification (e.g., Medical/Surgical = 0)
2	Body System	Organ system (e.g., Eye = 8, Urinary = T)
3	Root Operation	What was done (e.g., Excision, Repair, Replacement)
4	Body Part	Specific anatomical site operated on
5	Approach	How access was gained
6	Device	Device left in place, if any
7	Qualifier	Additional specificity

CIC Focus

Character 4 is one of the most commonly tested characters on the CIC exam. Errors in body part assignment directly impact MS-DRG grouping and coding accuracy.

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Body Part Grouping: The Core Concept

The PCS system does not assign a unique body part value to every discrete anatomical sub-structure. Many smaller or functionally related structures are grouped under a broader body part.

Grouping Rule

When a structure is not listed as its own body part in the tables, coders must use the body part that includes that structure per the Body Part Index. This is not approximation — it is the defined, guideline-supported method.

Common Grouping Examples by Body System

Clinical Term (Op Note)	Maps To (PCS Body Part)	Body System
Bruch’s membrane	Choroid, Left / Right	Eye
Ciliary zonule	Eye, Left / Right	Eye
Lacrimal punctum	Lacrimal Duct, Left / Right	Eye
Trigone of bladder	Bladder	Urinary
Detrusor muscle	Bladder	Urinary
Ureterovesical junction	Ureter, Left / Right	Urinary
Eustachian tube	Auditory Tube, Left / Right	Ear, Nose, Sinus
Ossicular chain	Auditory Ossicle, Left / Right	Ear, Nose, Sinus
Cochlea	Inner Ear, Left / Right	Ear, Nose, Sinus
Arytenoid cartilage	Larynx	Respiratory
Cricoid cartilage	Larynx	Respiratory
Prostatic urethra	Urethra	Urinary
Corpus spongiosum	Penis	Male Reproductive
Frenulum, tongue	Tongue	Mouth/Throat
Zonule of Zinn	Eye, Left / Right	Eye
Vermiform appendix	Appendix	Gastrointestinal
Pyloric antrum	Stomach, Pylorus	Gastrointestinal
Bowman’s capsule	Kidney, Left / Right	Urinary
Glomerulus	Kidney, Left / Right	Urinary
Bundle of His	Conduction Mechanism	Heart/Vessels
Sinoatrial node	Conduction Mechanism	Heart/Vessels
Circle of Willis	Intracranial Artery	Upper Arteries

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Body Part vs. Body System: Knowing the Difference

Term	Character	Example
Body System	2	Urinary System (T), Eye (8), CNS (0)
Body Part	4	Bladder, Kidney Left, Retina Right

Common Mistake

Do not confuse the body system (Character 2) with the body part (Character 4). The Body Part Index helps identify Character 4 specifically — the system is determined by the PCS table section selected.

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Bilateral Body Parts

Some body parts have a bilateral value in addition to left/right designations.

Body Part	Left Value	Right Value	Bilateral Value
Ovary	Ovary, Left	Ovary, Right	Ovaries, Bilateral
Fallopian Tube	Fallopian Tube, Left	Fallopian Tube, Right	Fallopian Tubes, Bilateral
Ureter	Ureter, Left	Ureter, Right	Ureters, Bilateral
Kidney	Kidney, Left	Kidney, Right	Kidneys, Bilateral
Lung	Lung, Left	Lung, Right	Lungs, Bilateral
Vas Deferens	Vas Deferens, Left	Vas Deferens, Right	Vas Deferens, Bilateral

Guideline Reminder

Per ICD-10-PCS guidelines, when a bilateral body part value exists and the procedure is performed bilaterally, one code with the bilateral value is assigned — not two separate codes.

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Laterality in the Body Part Index

Many body part entries include both left and right designations. The correct laterality must match the operative documentation.

Laterality Pitfall

If the operative report documents a right-sided procedure but the coder selects the left body part value, the resulting code is incorrect even if every other character is accurate. Always confirm laterality explicitly.

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Body Part Index vs. Device Aggregation Table vs. Body Part Spectrum

Three related but distinct PCS reference tools:

Tool	Purpose
Body Part Index	Maps anatomical terms → correct Character 4 body part value
Device Aggregation Table	Maps specific device names → general PCS device values (Character 6)
Body Part Spectrum	Defines the anatomical scope of a body part — what structures are included within it

CIC Exam Note

All three tables may appear in exam questions. The Body Part Index is the most frequently tested for anatomy-to-code mapping accuracy.

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Step-by-Step Coding Workflow Using the Body Part Index

1. Read the operative report → identify the anatomical structure involved
2. Look up the procedure in the Alphabetic Index → identify root operation and table
3. If the anatomical term does not appear as a body part in the table: → Consult the Body Part Index → Identify the "use" statement → this is your Character 4 value
4. Verify Character 4 in the appropriate PCS table
5. Assign remaining characters (5, 6, 7) from the table
6. Confirm the complete 7-character code

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CIC Exam Tips: Body Part Index

Study Strategy

• Memorize common groupings for high-volume systems: Cardiovascular, Urinary, Musculoskeletal, Neurological, GI
• Pay attention to structures that sound distinct but map to a single body part (e.g., sinoatrial node → Conduction Mechanism)
• Practice distinguishing structures that do have their own body part value vs. those that do not
• Know the bilateral body part rule cold — it is a high-yield exam topic
• When in doubt during the exam: consult the Body Part Index before assigning Character 4

Exam Pitfall

A common distractor is listing a specific sub-structure (e.g., cochlear duct) as a body part when it maps to a broader value (Inner Ear). The Body Part Index resolves this — trust it over anatomical intuition.

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Quick Reference: High-Yield Body Part Mappings

Sub-Structure	Correct PCS Body Part
Sinoatrial (SA) node	Conduction Mechanism
Atrioventricular (AV) node	Conduction Mechanism
Bundle of His	Conduction Mechanism
Purkinje fibers	Conduction Mechanism
Thoracic duct	Thoracic Duct
Cisterna chyli	Thoracic Duct
Glomerulus	Kidney
Bowman’s capsule	Kidney
Detrusor muscle	Bladder
Trigone	Bladder
Uvula	Soft Palate
Hard palate	Palate, Hard
Adenoids	Nasopharynx
Tonsils	Tonsil
Arytenoid cartilage	Larynx
Epiglottis	Epiglottis (own value)
Cochlea	Inner Ear
Semicircular canals	Inner Ear
Ossicular chain	Auditory Ossicle
Tympanic membrane	Tympanic Membrane
Mastoid air cells	Mastoid Sinus
Bruch’s membrane	Choroid
Ciliary zonule	Eye
Lacrimal punctum	Lacrimal Duct
Zonule of Zinn	Eye

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Related Notes

• ICD-10-PCS Body Part Index
• ICD-10-PCS Alphabetic Index
• ICD-10-PCS Character Structure
• ICD-10-PCS Device Aggregation Table
• ICD-10-PCS Coding Guidelines
• CIC Exam Study Plan

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References

1. CMS. ICD-10-PCS Official Guidelines for Coding and Reporting, FY2026.
2. CMS. ICD-10-PCS Reference Manual.
3. AAPC. Certified Inpatient Coder (CIC) Examination Study Guide.