14.4 Discontinued, Reduced, Bilateral, and Multiple Procedures
Key Takeaways
- Modifier 73 is HOPD/ASC discontinued after prep and arrival in the procedure room but before anesthesia; modifier 74 is after anesthesia or after the procedure starts; professional modifier 53 is not the facility tool
- Modifier 52 is reduced or discontinued service when anesthesia is not planned; elective cancellation before the patient is prepared and taken to the room is not reported
- Hospital OPPS bilateral surgery that takes modifier 50 is typically one line, 50, one unit, without RT/LT on that line; Medicare ASC bilateral reporting uses two lines or two units with LT/RT and does not copy the hospital 50 line
- OPPS status indicator T procedures take I/OCE multiple-procedure discounting; status indicator S does not; ASC 52 and 73 are not further multiple-procedure discounted, while 74 may be
- Device-intensive procedures billed with modifier 73 have the device offset removed at 100% before the discontinued-procedure payment adjustment; candidates follow current CPT plus CMS setting-specific claims instructions rather than one invented bilateral or multiple-procedure rule
14.4 Discontinued, Reduced, Bilateral, and Multiple Procedures
Quick Answer: 73 = facility case stopped after prep and arrival in the room, before anesthesia. 74 = stopped after anesthesia or after start (incision, intubation, scope inserted). 52 = reduced or discontinued when anesthesia is not planned. 53 = physician discontinued modifier, not the HOPD line. Elective cancellation before the room = no procedure code. Bilateral and multiple-procedure payment then follow CPT descriptors plus CMS hospital versus ASC claims instructions, including status indicator T versus S—not one homemade rule.
Section 4.3 taught the 73/74/52/53 fork. This section adds payment effects, device-intensive 73, the bilateral decision process, and how SI T multiple-procedure discounting interacts with discontinued and repeat modifiers. Independent OpenExamPrep teaching for COC learners; confirm current Addendum B status indicators and the codebook on exam day.
73 versus 74 versus professional 53
MCPM Chapter 4, §20.6.4, and Chapter 14, §40.4, are the facility discontinued-procedure instructions for HOPD and ASC.
Anesthesia for this hospital outpatient billing definition includes local, regional block(s), moderate sedation/analgesia (conscious sedation), deep sedation/analgesia, and general anesthesia. A colonoscopy under moderate sedation is an anesthesia-planned procedure for 73/74 purposes.
Modifier 73 (facility): the patient has been prepared (including procedural pre-medication when provided) and taken to the room where the procedure was to be performed, but anesthesia has not been administered. Termination is for extenuating circumstances or threat to well-being—not because the patient changed their mind in holding. Typical Medicare facility payment: 50% of the OPPS/ASC procedure amount. Chapter 14 example pattern: allergic reaction to a drug given in the ASC before induction, or retrobulbar hemorrhage on injection of a block that prevents continuation.
Modifier 74 (facility): termination after induction of anesthesia or after the procedure was started (CMS examples: incision made, intubation started, scope inserted), including physician discretion to stop, reduce, or cancel after anesthesia. Typical OPPS payment: full APC for that discontinued procedure, because facility resources were consumed similarly to a completed case. Chapter 14 example: after anesthesia and a preliminary incision, blood pressure spikes and the case stops.
Modifier 53 (professional): discontinued physician service. MCPM Chapter 4 states 53 is not approved for outpatient hospital services. The surgeon's CMS-1500 and the hospital's UB-04 can legitimately show different discontinued modifiers for the same clock time.
Elective cancellation is not reported. Patient has a cold at intake; case postponed before prep and transport to the room: no 73, no 52, no procedure line.
Several procedures planned. If one or more are completed, report the completed work as usual; do not report planned procedures that were never started. If none is completed, report the first planned procedure with 73 or 74 according to timing; do not add the unstarted others.
ASC documentation for terminated surgery must support reason for termination, services and supplies actually provided, what would have been done, time in each stage, and the HCPCS code that would have been reported if completed (Chapter 14 §40.4). Keep the operative/procedure note.
Modifier 52: reduced services and no-anesthesia discontinuation
Modifier 52 is the facility tool when a service is partially reduced, discontinued, or cancelled and anesthesia is not planned. That includes many discontinued radiology and other non-anesthesia procedures. MCPM Chapter 4: procedures without planned anesthesia that are discontinued, partially reduced, or cancelled after the patient is prepared and taken to the room are paid at 50% of the OPPS amount with 52. Chapter 14: beginning 2008, ASC discontinued radiology and other no-anesthesia procedures use 52 with a 50% reduction.
Do not use 52 to mean the payer usually packages the service. Do not use 52 on an unlisted code as a way to rewrite a descriptor. Do not use 52 when 73 or 74 applies. For radiology, if a more specific completed-procedure code exists, code the extent performed; use 52 on the intended code only when no code describes the reduced service (Chapter 4 §20.6.6).
Device-intensive + 73. For device-intensive procedures with modifier 73, CMS reduces the APC payment by 100% of the device offset before applying the discontinued-procedure adjustment. Current device-intensive definition (since January 1, 2019, as stated in Chapter 4): procedures that involve surgical implantation or insertion of an implantable device assigned a CPT or HCPCS code (including single-use devices) with a device offset exceeding 30% of the procedure's mean cost. You do not need to memorize every historical 40% APC-level definition; you do need to know that a 73 on a device-intensive case is not a plain 50% of the full APC.
Bilateral procedures: a decision process, not a slogan
There is no single universal line construction that is always right for every payer and every setting. COC items that name Medicare and the setting expect you to follow current CPT (is the code already bilateral? is it unilateral or bilateral by descriptor?) plus CMS claims processing for that setting.
Step 1 — Descriptor. If CPT already describes a bilateral procedure, or unilateral or bilateral, do not append 50 (MCPM Chapter 4 §20.6.2). Report with one unit unless a different CMS instruction applies.
Step 2 — Is it truly both sides at the same operative session? Modifier 50 is restricted to operative sessions in the hospital instruction. LT or RT identifies one side of a paired organ.
Step 3 — Hospital OPPS (MCPM Chapter 4 §20.6.2 and NCCI Chapter 1 MUE discussion). When modifier 50 applies: one line, modifier 50, one unit. Do not report RT and LT when 50 applies. Do not submit two lines to report the bilateral procedure using 50. NCCI ties many surgical MUE values to that 50-plus-one-UOS pattern. I/OCE bilateral discount formulas then interact with whether the line is SI T and whether 50 is present; do not invent a 150% professional-fee-schedule bilateral payment as if it were OPPS.
Step 4 — Medicare ASC (MCPM Chapter 14 §40.5 and NCCI). Chapter 14: a procedure performed bilaterally in one session is reported as two procedures, either as a single unit on two separate lines or with 2 in the units field on one line. The multiple-procedure reduction of 50% applies to bilateral procedures that are subject to multiple-procedure discounting—so the second side is not automatically paid as if it were an unrelated full primary. NCCI's surgical MUE text states the physician/HOPD 50-with-one-UOS requirement does not apply to an ASC; an ASC should report bilateral surgery on two claim lines, each with 1 UOS, using LT and RT. MAC education often states ASCs do not append modifier 50. When a stem says Medicare ASC, do not copy the hospital one-line-50 pattern.
Step 5 — Other payers. Commercial and Medicaid plans may want 50, or RT/LT, or both. The exam skill is to read the stem's payer and setting, then apply CPT plus that payer's published rule—not to force every claim into one line pattern you memorized in CPC class.
Never stack 50 + LT + RT on the same hospital OPPS bilateral line.
Multiple procedures: SI T versus SI S, and discontinued interaction
OPPS (MCPM Chapter 4 §10.1 and I/OCE). Status indicator T: separately paid, multiple-procedure reduction applies when two or more T services are billed the same day. Status indicator S: separately paid significant procedure not discounted when multiple. The I/OCE ranks T lines by payment; the highest T is not discounted; other T lines are. Non-T lines are ignored in that ranking. T lines with 76, 77, 78, and/or 79 are not multiple-procedure discounted under that I/OCE rule.
ASC (Chapter 14 §40.5). When multiple discount-eligible surgical procedures occur in the same session: 100% of the highest paying, 50% of the others, using the calendar-year OPPS/ASC list of which procedures are discount-eligible. Ranking uses the lower of billed charge or ASC payment. Modifier 73 and 52 ASC surgical services are not subjected to further multiple-procedure reductions. Modifier 74 may still take the multiple-procedure discount if that procedure is discount-eligible.
That is why a completed SI T cholecystectomy plus a completed SI T hernia repair is a multiple-procedure payment problem, while a completed SI S procedure next to a T procedure does not take the T haircut on the S line. Appending 51 does not create that logic. Changing a T code to an S code to avoid the discount is not coding.
Facility scenario
Medicare HOPD: device-intensive implantable procedure. Patient prepared, in the OR, induction not started; malignant arrhythmia on the table; case stopped. Facility: intended CPT with modifier 73. Payment is not 50% of the full device-inclusive APC: CMS removes 100% of the device offset first, then applies the discontinued-procedure reduction. No device HCPCS if the device was not opened and used, consistent with the record.
Second case: Medicare ASC bilateral knee arthroscopy, both sides completed, codes subject to multiple-procedure discounting. Do not bill one line with 50 the way the HOPD instruction describes. Report two lines with LT and RT (or follow Chapter 14's two-unit example), expect the second side to take the ASC multiple-procedure reduction if the procedure is discount-eligible, and confirm the current year's ASC list rather than assuming every arthroscopy discounts.
Third case: HOPD SI T endoscopy completed, then a same-day unplanned related return (SI T) with 78. I/OCE does not apply the usual T multiple-procedure discount to the 78 line. A second unrelated SI T procedure the same day without 76/77/78/79 still discounts. SI S imaging in between is outside the T ranking.
Sources
A Medicare hospital outpatient device-intensive implant case is stopped after the patient is prepared and taken to the operating room, but before anesthesia is induced. Which discontinued-procedure reporting and payment idea matches CMS Chapter 4?
Which pair correctly contrasts modifier 52 with modifiers 73/74 and elective cancellation on hospital outpatient and ASC facility claims?
A COC item involves bilateral surgery and a second procedure on the same day. Which statement reflects CMS hospital OPPS, ASC, and status-indicator rules rather than a single invented billing pattern?