D4342 is the limited-scope SRP code: same procedure as D4341, fewer teeth per quadrant. The main billing question is whether to use D4341 or D4342 when a quadrant has three or four affected teeth. The answer depends on which teeth meet the perio threshold, not the total number in the quadrant. This page is the working reference.
What D4342 covers
D4342 reports scaling and root planing on one, two, or three teeth in a quadrant. The procedure is identical to D4341: removal of plaque, calculus, and bacterial toxins from root surfaces below the gumline. The only difference is the count of teeth involved.
The clinical threshold is the same: pocket depths of 4mm or greater, bleeding on probing, and radiographic evidence of bone loss. A periodontitis diagnosis, not gingivitis.
It does not cover:
- Four or more teeth in a quadrant. Use D4341.
- A full-mouth gingivitis case. Use D4346.
- Maintenance recall after active therapy. Use D4910.
- Routine prophy on a periodontally healthy patient. Use D1110.
When to bill D4342
Bill D4342 when:
- One, two, or three teeth in a quadrant meet the SRP threshold.
- Those teeth have pocket depths of 4mm or greater.
- Bleeding on probing is present at the affected sites.
- Radiographs show bone loss at those teeth.
Do not bill D4342 for:
- A quadrant with four or more qualifying teeth. Use D4341.
- A patient with generalized gingivitis but no bone loss. Use D4346.
- A patient already on perio maintenance. Use D4910.
- Isolated 4mm pockets with no bleeding and no radiographic bone loss. The case is probably a prophy or gingivitis, not SRP.
Top reasons D4342 gets denied
- Documentation gaps. The perio chart doesn’t show pocket depths or bleeding on probing at the affected teeth. The carrier denies for “insufficient information.”
- Should have been D4341. The quadrant actually had four or more qualifying teeth. The carrier may correct upward (uncommon) or deny pending submission of the right code.
- Should have been D4346 or D1110. The chart didn’t support a periodontitis diagnosis. The carrier downgrades.
- Frequency exceeded. Same quadrant had SRP within the lookback window.
- Quadrant mismatch. The teeth charted don’t match the quadrant billed.
D4342 versus D4341: count by qualifying teeth
The line between D4341 and D4342 is not the count of teeth in the quadrant. It’s the count of teeth in the quadrant that meet the SRP threshold.
Examples:
- A quadrant has eight teeth. Three of them have 5mm pockets with bleeding. The other five are healthy. Bill D4342.
- A quadrant has six teeth. Four of them have 4mm-6mm pockets with bleeding. The other two are healthy. Bill D4341.
- A quadrant has seven teeth. Two of them have 4mm pockets with bleeding. The remaining five are at 3mm with no bleeding. Bill D4342.
Coding D4341 when only two or three teeth qualify is an over-statement. Carriers cross-check against the perio chart, and the audit history hurts future claims on the same patient.
Documentation that supports the claim
The claim needs:
- Six-point probing chart showing pocket depths at the affected teeth.
- Bleeding on probing marked at those sites.
- Recent radiographs showing bone loss at the affected teeth.
- A periodontitis diagnosis in the chart note.
- Quadrant designation that matches the charted teeth.
The standard for D4342 is no lower than for D4341. The carrier needs to see real perio findings, just localized to fewer teeth.
Example case
A 36-year-old patient presents for a comprehensive perio evaluation. Probing reveals 4mm-5mm pockets with bleeding at teeth #18 and #19, both lower-left. The remaining teeth in the quadrant are healthy. Radiographs show localized bone loss at #18 and #19 only.
Billing steps:
- Chart six-point probing for the quadrant, with bleeding marked at the affected sites.
- Submit D0180 for the comprehensive perio evaluation.
- Submit D4342 for the lower-left quadrant with the perio chart and films attached.
- Schedule the patient for D4910 maintenance after the active therapy heals (typically four to six weeks post-SRP).
What to get right in your PMS
- Count qualifying teeth carefully before coding. Three teeth is D4342; four teeth is D4341. The fee difference is significant and so is the audit risk of over-coding.
- Attach the perio chart and films to the claim. A six-point chart is what the carrier expects.
- Quadrant designation needs to match the chart. Errors here cause clean denials.
- If a single tooth qualifies, D4342 is still correct. Don’t avoid the code because it’s just one tooth.
- Transition the patient to D4910 maintenance after active therapy. Going back to D1110 prophy on a perio patient undoes the trail.
FAQs
- When do I bill D4342 instead of D4341?
- Count the teeth in the quadrant that meet the SRP threshold (pocket depth of 4mm or greater, bleeding on probing, radiographic bone loss). One to three such teeth in a quadrant is D4342. Four or more is D4341. The total tooth count in the quadrant doesn't matter. Only the count of teeth that meet the threshold.
- Can I bill D4342 if only one tooth needs SRP?
- Yes. A single affected tooth in a quadrant qualifies for D4342 if it meets the threshold (pocket depth, bleeding, bone loss). The same documentation standard applies as for a multi-tooth case.
- Why did the carrier downgrade my D4342 to a prophy?
- Usually because the documentation didn't support a periodontitis diagnosis. A single 4mm pocket without bleeding or bone loss reads as borderline gingivitis to most reviewers. If the chart shows isolated perio with clear documentation, appeal with the perio chart and radiographs.
- How often will a plan pay for D4342?
- Most plans pay D4342 once per quadrant every 24 months, the same frequency as D4341. The clock runs per quadrant, so a patient who had D4342 in the upper-right two years ago can still have SRP performed on a different quadrant without hitting the cap. Verify the specific plan before treatment. Some plans extend the lookback to 36 months.
- Can D4341 and D4342 appear on the same claim for different quadrants?
- Yes. The codes are per quadrant, not per visit. A patient with generalized periodontitis might have four qualifying teeth in two quadrants (D4341 on each) and two qualifying teeth in another quadrant (D4342 on that one). All three lines can post on the same claim with the perio chart and films attached. Each line carries its own frequency clock.
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.