Apply the codes to those outpatient charts? A quick guide to give you the basics!

Quick-start workflow (use this every case)

1. Identify the encounter type & roles

   • Professional coder (surgeon/anesthesiologist): CPT®/HCPCS for services + modifiers; ICD-10-CM for diagnoses.

   • Facility coder (ASC/HOPD): CPT/HCPCS for procedures/supplies + revenue codes; no ICD-10-PCS (that’s inpatient only).

2. Pull the right documentation

   • Op note (pre/post dx, indications, approach, body part(s), laterality, techniques, devices, complications).

   • Anesthesia record (ASA status, time, qualifying circumstances).

   • Pathology/endoscopy report if applicable.

   • Implants/device sheets.

3. Code diagnoses (ICD-10-CM)

   • Use post-op diagnosis if it’s more specific than pre-op.

   • Code the reason for surgery first. Add relevant comorbidities that affect care.

4. Code procedures (CPT/HCPCS)

   • Start with the primary procedure (greatest work/RVU), then secondaries if allowed.

   • Check NCCI edits and bundling rules before adding additional procedures.

5. Apply modifiers (CPT & HCPCS) as needed

   • Laterality, multiple procedures, discontinued, staged/related, assistant surgeon, bilateral, distinct service, device-dependent endoscopy, etc.

6. Assign anesthesia (if you’re coding it)

   • Base code (by anatomic site) + time units + qualifiers (e.g., hypothermia, emergency).

7. Check payer policy

   • Medical necessity LCDs/NCDs, ASC vs physician differences, global period impacts, prior auth, coverage lists.

8. Scrub

   • Diagnosis supports procedure? Laterality consistent? Device documented? Correct global day? No forbidden pairs per NCCI?

Core concepts you must know

1) ICD-10-CM (diagnosis) basics

• Code the most specific confirmed condition post-op.

• Symptoms usually not coded when integral to a confirmed dx.

• Laterality and episode-of-care characters matter (e.g., M17.11 unilateral primary OA, right knee).

2) CPT® surgery code structure

• Organized by body system; look for approach (open vs endoscopic vs percutaneous), extent (diagnostic vs therapeutic), number of structures, with/without items (e.g., implant).

• Endoscopy families have base/parent “diagnostic” codes; therapeutic codes include the diagnostic.

3) Modifiers you’ll use all the time

• -50 Bilateral procedure

• -51 Multiple procedures (physician pro fees; facilities handle via grouper)

• -59 Distinct procedural service (only when truly separate; consider XE/XS/XP/XU payer-preferred)

• -52 Reduced services / -53 Discontinued (physician) / -74 Discontinued after anesthesia (facility)

• -22 Increased procedural services (needs strong justification)

• -24/-25/-57 E/M during global (unrelated, significant & separate, decision for surgery)

• -79/-78 Unrelated vs related return to OR during global

• -RT/-LT Laterality (some payers prefer over -50)

• AS/80/81/82 Assistant surgeon indicators (payer-specific)

4) Global periods (physician billing)

• Minor (0–10 days) vs Major (90 days). Post-op visits usually included. Use E/M modifiers appropriately if unrelated.

5) NCCI bundling logic (must check!)

• Some procedures are mutually exclusive or component of another. Only override with -59/X{E,S,P,U} when fully supported (different lesion, different site, separate session).

6) ASC vs Physician differences

• Physician: CPT pro fees, global rules, modifiers like -24/-25 matter a lot.

• ASC: Paid by ASC fee schedule; certain device-dependent codes require correct C-codes/HCPCS; discontinued cases use -73/-74 (facility equivalents).

7) Anesthesia coding (quick primer)

• Choose anesthesia CPT by site/procedure (e.g., knee, shoulder).

• Units = base + time + modifiers (qualifying circumstances like emergency).

• Document start–stop times and ASA physical status.

Common outpatient surgery examples (pattern recognition)

A) Arthroscopic knee debridement (right), OA

• Dx: M17.11 (unilateral primary OA, right knee)

• CPT: 29881 (meniscectomy) or 29877/29879 (chondroplasty/microfracture) depending on op note details.

• Mods: -RT; add -59 if a truly separate compartment service is performed in addition to primary.

B) Cataract extraction with IOL (left)

• Dx: H25.12 (age-related nuclear cataract, left)

• CPT: 66984 (routine extracapsular with IOL) or 66982 (complex—needs device/technique complexity documented).

• Mods: -LT; consider -22 if complex and payer criteria met.

C) Screening colonoscopy converted to polypectomy

• Dx: Z12.11 (screening), plus polyp finding (e.g., K63.5). Some payers want Z12.11 first with modifier 33 on the CPT to indicate preventive.

• CPT: 45385 (snare polypectomy) — therapeutic code replaces the diagnostic.

• Mods: 33 (preventive) or -PT (Medicare screening turned diagnostic); no separate 45378.

D) Inguinal hernia repair, initial, right

• Dx: K40.90 (unilateral, unspecified hernia without obstruction/gangrene—more specificity if documented).

• CPT: 49505 (open initial) or 49650 (laparoscopic).

• Mods: -RT; add mesh device info if required by payer for documentation (not separately coded for typical inguinal).

E) Carpal tunnel release, left

• Dx: G56.02 (carpal tunnel syndrome, left upper limb)

• CPT: 64721 (neuroplasty; median nerve at carpal tunnel)

• Mods: -LT; bilateral would be -50 or -RT/-LT (payer-specific).

Tiny decision checklist (pin this)

• Is the post-op dx more specific? Use it.

• Did I pick the most definitive procedure (therapeutic replaces diagnostic)?

• Any bundling edits? If I unbundle, can I defend with site/lesion/compartment separation?

• Laterality present everywhere it should be?

• Do global period rules affect any E/M same day/after?

• Does the record support every modifier?

• For ASC: Did I use the right discontinued modifier (-73/-74), and include device/implant details when needed?

Practice: code these 6 cases

Try them first; answers are below.

1) Shoulder arthroscopy with rotator cuff repair (right).Findings: full-thickness supraspinatus tear; bursectomy performed.Dx: full-thickness R supraspinatus tear due to degeneration.

2) Screening colonoscopy; two 6 mm polyps in sigmoid removed by cold snare; normal rest.

3) Cataract extraction with IOL (complex) left eye using iris expansion device; dense brunescent nucleus; capsular staining used.

4) Carpal tunnel release bilateral, same session.

5) Lap inguinal hernia repair: primary right indirect hernia with mesh; separate diagnostic laparoscopy of left side only (no hernia).

6) Knee scope: medial meniscectomy and chondroplasty in a different compartment (patellofemoral), right knee.

Answers & brief rationale

1)

• Dx: M75.121 (complete rotator cuff tear or rupture, right, not specified as traumatic)

• CPT: 29827 (arthroscopic rotator cuff repair)

• Mods: -RT

• Rationale: Bursectomy is integral; 29827 is primary therapeutic.

2)

• Dx: Z12.11 (screening), K63.5 (polyp)

• CPT: 45385 (snare polypectomy)

• Mods: 33 (preventive) or -PT for Medicare

• Rationale: Therapeutic replaces diagnostic; keep screening intent.

3)

• Dx: H25.12 (nuclear cataract, left)

• CPT: 66982 (complex cataract with IOL)

• Mods: -LT

• Rationale: Use of iris expansion/rhexis support qualifies as complex when documentation supports increased work.

4)

• Dx: G56.01 (right), G56.02 (left)

• CPT: 64721 x1

• Mods: -50 (bilateral) or report 64721-RT and 64721-LT (payer preference); some payers require one line with -50.

• Rationale: Same session bilateral.

5)

• Dx: K40.90 (right inguinal hernia, without obstruction/gangrene); Z03.89 (observed for suspected condition not found) optional if payer allows.

• CPT: 49650 (lap inguinal repair, initial) only

• Mods: -RT

• Rationale: Separate diagnostic laparoscopy is bundled into laparoscopic hernia repair per NCCI; not separately billable.

6)

• Dx: M23.21 (derangement medial meniscus due to old tear/injury, right) or appropriate meniscal tear code; and M22.41 (chondromalacia patella, right) if documented.

• CPT: 29881-RT (medial meniscectomy) + 29877-59-RT (chondroplasty, separate compartment)

• Rationale: Chondroplasty in a separate compartment may bypass bundling with proper documentation; use -59 (or XS) to show distinct compartment.

What to study next (short plan)

1. Your top specialties (ortho, GI, ophtho, general surgery): read each section intro in the CPT book and highlight typical parent/child endoscopy codes.

2. NCCI Policy Manual (free): skim the chapters for your specialties to understand edit logic and “separate site/lesion/compartment” standards.

3. ASC vs Physician differences: learn facility discontinued modifiers (-73/-74), device C-codes, packaging rules (just the concepts).

4. Payer policies: bookmark your top payers’ surgical policies and Medicare LCDs for common procedures (e.g., colonoscopy, cataract).

5. Build a “coding cover sheet” template you attach to each case (Dx list, primary CPT, secondary CPTs with justification, modifiers with reason, NCCI check result, devices, global period).

If you want, I can make a one-page cheat sheet and a fill-in coding cover sheet (Word/Excel) with dropdowns for common modifiers and a spot to paste op-note evidence.