D9243 is the CDT code for each additional 15-minute increment of IV moderate (conscious) sedation after the first. It's an add-on that never stands alone — the first 15 minutes is reported with D9239.
D9243 stacks in 15-minute units on top of the first increment, so the time math and the start and stop times on the record have to line up exactly — and how much of it gets paid depends on how the plan covers sedation.
What D9243 covers
D9243 reports each additional 15-minute increment of intravenous moderate sedation, also called conscious sedation, after the first increment. Moderate sedation is a drug-induced state where the patient responds to verbal commands and keeps a patent airway without help. When the drugs are titrated through an IV line, the time is billed in 15-minute units.
The first 15 minutes is D9239. Every 15-minute block after that, or any portion of one, is a unit of D9243. The two codes work as a pair: D9239 opens the case, D9243 extends it.
D9243 does not cover:
- The first 15-minute increment of IV moderate sedation. That is D9239.
- Deep sedation or general anesthesia. Those are D9222 (first 15 minutes) and D9223 (each additional 15 minutes).
- Nitrous oxide as a single agent. That is D9230.
- Sedation delivered by a route other than intravenous. The enteral and other-route codes are separate.
When to bill D9243
Bill D9243 when:
- The patient is under IV moderate sedation and the documented time runs past the first 15 minutes.
- You have already reported D9239 for the first increment on the same claim.
- The anesthesia record shows the start and stop times that support each additional unit.
Do not bill D9243 for:
- A case of 15 minutes or less. That is D9239 alone.
- Deep sedation or general anesthesia. Use D9222 and D9223.
- Time the patient was recovering after the provider’s continuous attendance ended. Sedation time stops when the patient can be left with trained staff.
How the time units stack
Moderate IV sedation is billed by elapsed time, not by procedure. The clock starts when the doctor begins administering the sedative drugs and stops when the patient is stable enough to be monitored by trained personnel without the provider’s continuous presence.
Worked example for a 50-minute case:
- First 15 minutes: D9239, one unit.
- Minutes 16 through 30: D9243, one unit.
- Minutes 31 through 45: D9243, one unit.
- Minutes 46 through 50: D9243, one unit (any portion of a 15-minute block counts as a full unit).
So a 50-minute case is D9239 plus three units of D9243. The math is straightforward once the start and stop times are on the record. Where claims fall apart is when the times are missing and the carrier has nothing to adjudicate the add-on units against.
D9243 versus D9239, D9222, and D9223
These four codes are easy to confuse because they share the same 15-minute time structure. The two axes that separate them are depth of sedation and first-versus-additional increment.
- D9239 is IV moderate (conscious) sedation, first 15 minutes.
- D9243 is IV moderate (conscious) sedation, each additional 15 minutes.
- D9222 is deep sedation or general anesthesia, first 15 minutes.
- D9223 is deep sedation or general anesthesia, each additional 15 minutes.
Moderate sedation keeps the patient responsive to verbal commands. Deep sedation and general anesthesia take the patient to a state where purposeful response is reduced or absent. Picking the moderate pair (D9239/D9243) when the record describes deep sedation, or the reverse, is a coding error a carrier can catch from the anesthesia record. Match the code pair to the documented level of sedation, then match the increment to the documented time.
The 2026 nitrous oxide change
Starting in 2026, CDT treats nitrous oxide as part of the anesthesia service when it is used along with other sedation drugs. D9230 is reported only when nitrous is the single agent administered. For a case that uses IV moderate sedation plus nitrous, the sedation time is captured entirely by D9239 and D9243. Billing D9230 on top of that for the same visit is no longer correct. This trips up offices that previously added a nitrous line to every sedation claim out of habit.
Documentation that supports the claim
The anesthesia record needs:
- Start time, defined as when drug administration began.
- Stop time, defined as when the provider’s continuous attendance ended.
- The drugs given, doses, and route (intravenous for this code pair).
- Vital signs monitored throughout the case.
- The procedure performed under sedation and the reason sedation was indicated.
For the claim itself, the medical-necessity narrative matters most. A line tying the sedation to the procedure or to a documented patient condition prevents the common “not necessary” denial. “IV moderate sedation indicated for surgical extraction of four impacted third molars, total sedation time 50 minutes” does more work than a bare code with no context.
Plan-dependent coverage
Sedation benefits vary widely. Some plans cover it only for specific surgical procedures, some require prior authorization, and some exclude it entirely for adult patients outside of medical necessity. Many cap the total sedation minutes they will pay, which means later units of D9243 may be denied even when the clinical record supports them.
Verify the anesthesia benefit before the appointment, the same as any other benefit. If the plan does not cover sedation for the planned procedure, the patient owes the fee, and they should know that before they are in the chair.
What to get right in your PMS
- Always report D9239 before D9243. D9243 is an add-on. A claim with the add-on and no first unit is an orphan and gets rejected.
- Capture start and stop times on the anesthesia record at the time of treatment. Times reconstructed later are the first thing a sedation audit challenges.
- Stop billing D9230 separately when nitrous rides along with IV sedation. The 2026 change folded combined nitrous into the anesthesia service.
- Match the depth of sedation to the code pair. Moderate is D9239/D9243; deep and general are D9222/D9223. The record has to agree with the code.
- Verify the sedation benefit and any minute cap before quoting the patient. Coverage is plan-specific, and later add-on units are where caps bite.
FAQs
- Can D9243 be billed by itself?
- No. D9243 reports each additional 15-minute increment of IV moderate sedation after the first increment, which is D9239. A claim with D9243 and no D9239 will be denied or rejected as an orphan add-on. Always report D9239 for the first unit, then D9243 for each subsequent unit.
- How many units of D9243 can I report?
- It depends on the documented sedation time. After the first 15 minutes (D9239), each additional 15-minute increment, or any portion of one, is one unit of D9243. A 50-minute case is D9239 plus three units of D9243. Many plans cap the total sedation time they will pay, so check the benefit before assuming all units reimburse.
- When does the sedation clock start and stop?
- Sedation time generally starts when the doctor begins administering the drugs and ends when the patient is stable enough to be monitored by trained staff and the provider's continuous attendance is no longer required. The anesthesia record needs both times. Carriers that audit sedation claims look at the start-and-stop documentation first.
- Does D9243 cover nitrous oxide given during the same case?
- Under the 2026 CDT changes, nitrous oxide used alongside other sedation drugs is considered part of the anesthesia service, not a separate line. D9230 is reported only when nitrous is the single agent. So if a case uses IV moderate sedation plus nitrous, the time is captured by D9239 and D9243, and D9230 is not billed separately.
- Will insurance pay for moderate sedation on a routine procedure?
- That is plan-dependent. Many plans pay sedation only when it is medically necessary, often tied to the procedure (surgical extractions, extensive treatment) or to a documented patient condition. A routine restorative visit with sedation requested for anxiety alone is frequently denied as not necessary. Read the plan's anesthesia language before quoting the patient.
Related codes
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CDT codes are maintained by the American Dental Association. This page is an editorial billing guide, not the official ADA code descriptor. Verify current coverage policies with each carrier before submitting claims.