How to Bill Timed CPT Codes: The 8-Minute Rule Explained for SLPs

For most speech-language pathologists, billing has never involved a stopwatch. You saw the patient, you documented the session, and you billed one unit of CPT 92507. One session, one unit, done. Timed CPT codes were something SLPs mostly read about, not something you actually used.

That's about to change. When CPT 92507 is being deleted in 2027, the untimed workhorse code is replaced by a family of timed codes, and timed billing runs on rules you've probably never had to learn. You may have heard your PT and OT colleagues mention "the 8-minute rule." Here's the catch: the version that applies to your new codes isn't quite the one they're describing.

So let's slow down and walk through it. This post covers the difference between timed and untimed codes, how minutes turn into billable units, the specific time thresholds in the new SLP structure, a few worked examples, and how all of it differs from the PT/OT 8-minute rule.

Timed vs. Untimed Codes: The Difference That's About to Matter

Start with the distinction that's been easy to ignore until now. An untimed code is billed once per day regardless of how long you spent providing the service.¹ That's why 92507 felt so simple. A 25-minute session and a 55-minute session both billed the same single unit, because the length of the visit never entered the math.

A timed code works differently. It carries a time designation right in the descriptor, language like "initial 30 minutes" or "each additional 15 minutes," and it can be billed more than once to reflect the total treatment time.¹ The minutes stop being background information and become the thing you actually report.

Here's why this snuck up on the profession. Nearly all SLP treatment codes have been untimed, so most SLPs have never had to think in units-per-minute.¹ The few timed codes that existed sat out at the edges of practice, things like device evaluations and cognitive testing. The 2027 change flips the default for everyday individual treatment, which is why every SLP and every biller in your office is about to need this.

The 8-Minute Rule, Explained Without the Jargon

The 8-minute rule is Medicare's method for turning treatment minutes into billable units on a timed code. The short version: you need at least 8 minutes of a 15-minute service before you can report one unit.³ Fall short of 8 minutes and there's no unit to bill.

From there it climbs in 15-minute steps. For codes built on 15-minute increments, the units break down like this:

The logic underneath is a midpoint. You earn a unit once you pass the halfway mark of the increment, since half of 15 rounds up to 8. ASHA frames the same idea from the other direction: bill a timed code when your face-to-face time is at least 51% of the time named in the descriptor.³

One point worth pinning down before we go further, because it's the source of most confusion. The "8 minutes" is the floor for a single 15-minute unit. It is not a universal threshold that governs every timed code you'll ever touch. That matters a lot for the new SLP codes, which don't start at 15 minutes.

How the New SLP Codes Actually Count Minutes

The codes replacing 92507 are built as base-and-add-on pairs, one pair for each of five disorder areas.² The base code covers the initial 30 minutes of treatment. Each add-on covers each additional 15 minutes after that. So the structure isn't a flat run of 15-minute units. It's a 30-minute base with 15-minute steps stacked on top.

That base changes the threshold. Because the base code describes 30 minutes, its midpoint is 16 minutes, not 8.² You have to spend at least 16 minutes on a disorder area before that base code is billable at all. A session that runs 12 minutes on a single area doesn't clear the bar. ASHA has spelled out the ranges: you'll need 16 to 37 minutes to report the base, and 8 to 22 minutes past the base to add one add-on unit.²

Now the part that's easy to miss. The threshold applies to time spent on a single disorder area, not to the total length of the visit.² If you split a 30-minute session between two disorder areas, you might not reach 16 minutes on either one. Same clock on the wall, very different billing outcome. That per-area accounting is new territory, and it's exactly the kind of detail your notes will need to capture.

A quick reminder on the numbers themselves. ASHA is currently using placeholders like 92X0X and 92X1X because the real five-digit codes won't publish until the 2027 CPT code set comes out, expected in the fall of 2026.² The structure, though, is already confirmed. Base for the first 30 minutes, add-on for each additional 15.

Worked Examples: Minutes to Units

Numbers land better than rules, so let's run a few. Picture a private-practice pediatric SLP working through a typical week.

A 40-minute fluency block. The first 30 minutes are the base. That leaves 10 additional minutes, which falls in the 8-to-22 range for an add-on. So you bill the base code plus one add-on.

A 25-minute articulation session. Twenty-five minutes sits inside the 16-to-37 window, and there aren't enough minutes past the base to earn an add-on. That's the base code only, one unit.

A 55-minute language session. Thirty minutes cover the base, which leaves 25 additional minutes. That extra time lands in the 23-to-37 band, which is worth two add-ons. So you report the base plus two add-ons for the full 55 minutes.

Now the one nobody likes. A rushed 12-minute check-in spent entirely on one disorder area. Twelve minutes is below the 16-minute base floor, so there's no billable base code for that area that day. The move here isn't to round up or pad the note. It's to document honestly what you did, lean on medical necessity to support the encounter, and let the record stand on its own.

For everyday reference, here's the whole base-and-add-on structure at a glance:

Why This Isn't Exactly the PT/OT 8-Minute Rule

If you share a clinic with physical or occupational therapists, you've heard the 8-minute rule described a certain way, and it doesn't quite match what you just read. That's not you misremembering. The mechanics really are different.

The classic PT/OT version treats every timed code as a 15-minute increment, and Medicare sums the total timed minutes across all of those mixed codes before dividing them into units.³ Everything starts at 8 minutes because everything is a 15-minute unit. The new SLP codes don't work that way. They lead with a 30-minute base at a 16-minute threshold, then add 15-minute steps, and they're organized per disorder area rather than pooled into one running total.

There's a second wrinkle worth knowing about. The AMA's "Rule of Eights" applies the 8-minute threshold to each code on its own, while the CMS 8-minute rule sums timed minutes across codes.³ Some commercial payers follow one, some follow the other, so it's worth confirming the rule each of your payers actually uses.⁴

The takeaway is simple enough. When your PT colleague says "you need 8 minutes," that number lives in the add-on step of your codes, not in whether you can bill the visit at all. Your base code answers to 16.

Getting Your Documentation Ready Before 2027

Nothing about your billing changes tomorrow. ASHA is clear that SLPs should keep reporting 92507 for individual treatment right up until the switch.⁴ But the habit that timed billing demands is worth building now, while the stakes are still low.

Start recording actual treatment minutes, and note which disorder area you spent them on, even though 92507 doesn't require it. The code number is the easy part. Rewiring how you track a session is the part that takes a few months to feel natural. A defensible time record captures three things: the minutes on task, the disorder area they applied to, and the medical necessity behind the time.

And remember what auditors look for. Total session time isn't enough on its own. They want the actual treatment minutes that support the units you billed, which is a higher bar than most untimed-era notes were built to clear. Getting the Medicare billing for speech therapy details right now saves a scramble later, and it's a good moment to review the common SLP billing mistakes that trip clinics up before new scrutiny arrives.

This is also a teaching moment for anyone running a university clinic. The students you supervise in the fall of 2026 will graduate straight into timed billing, so showing them how to log minutes per disorder area from their very first note gives them a real head start.

Learn the Minutes Now, Not in January 2027

Here's the whole thing in a sentence. Timed billing runs on minutes and thresholds, and the new SLP structure has a 16-minute base floor and an 8-minute add-on step, counted per disorder area rather than per visit. Once you internalize those two numbers, the rest is arithmetic.

The one habit worth building today is logging real treatment minutes against the right disorder area. It pays off in any system you use, and it turns the 2027 switch from a scramble into a formality.

Want documentation that already captures the detail timed codes demand? ClinicNote's time-stamped SOAP notes, per-disorder-area templates, and service-code integration are built to map your minutes to the right units without adding busywork to your day. Get a demo and see how it fits your clinic.

Sources

1. https://www.asha.org/practice/reimbursement/coding/timedcodesfaqs/
2. https://www.asha.org/practice/reimbursement/coding/new-speech-language-pathology-treatment-codes-replacing-92507/
3. https://www.asha.org/practice/reimbursement/medicare/slp_coding_rules/
4. https://www.asha.org/news/2026/update-on-cpt-code-92507-valuation-review-underway/