Insurance Billing

The 8-Minute Rule for Dietitians: How to Count MNT Billing Units

How the 8-minute rule works for MNT codes 97802 and 97803: the full unit table, worked examples, what counts as billable time, and why rounding down costs you.

By Alva Health Team · Published July 12, 2026 · ← All articles

Ask ten dietitians how many units a 52-minute follow-up is and you'll get at least three answers. Some bill 2 units "to be safe." Some bill 3. Some bill whatever they billed last time. The difference isn't trivia — at typical per-unit rates, one under-billed unit per day quietly removes thousands of dollars from your practice over a year.

The 8-minute rule exists precisely so there's no guessing. It's a mechanical conversion from documented face-to-face minutes to billable units, and once you internalize the table, unit counting takes zero thought.

Here's the rule, the full table, worked examples, and — just as important — what time you're allowed to count in the first place.

Why MNT codes are time-based at all

97802 and 97803 don't describe "a session." They describe 15 minutes of medical nutrition therapy. You don't bill one code per visit — you bill one code with a unit count that reflects how long the visit actually was. (97804, the group code, works the same way in 30-minute units.)

That means a 30-minute follow-up and a 60-minute follow-up are the same CPT code at different quantities — and they pay differently. Payers reimburse per unit, so your time counting is your revenue counting.

The 8-minute rule, explained in one sentence

CMS's rule for time-based codes: you may bill a unit once you've passed the midpoint of that unit. Half of 15 minutes is 7.5, so the first unit unlocks at 8 minutes, the second at 23, and so on — each threshold is 15 minutes after the last.

The full unit table

Print it, tape it to your monitor, or better: let your software count for you. Two caveats before you rely on it blindly:

• Medicare follows this rule. Most commercial payers follow the same midpoint logic for MNT codes, but some have their own unit policies — check the payer's MNT policy or provider manual.
• Unit caps override the math. A payer that caps MNT at 4 units per visit pays 4 units for your 90-minute session no matter what the table says.

Worked examples

A 52-minute follow-up. 52 minutes falls in the 38–52 range: 97803 × 3 units. Note how close the edge is — at 53 minutes you'd bill 4 units. If your sessions habitually run "about 50 minutes," you are one honest scheduling adjustment away from a fourth unit on every visit. Conversely, don't stretch a 50-minute note to 53; bill what happened.

A 90-minute initial assessment. 90 minutes falls in the 83–97 range: 97802 × 6 units — if the payer allows 6 units on one date of service. This is exactly why you verify benefits before a long initial: if the plan caps visits at 4 units, you want to know before you give away two units of work, not when the remittance arrives.

A 20-minute quick check-in. 8–22 minutes: 97803 × 1 unit. Short visits are billable — many RDs assume anything under half an hour isn't worth filing. It is.

A 7-minute phone call. Zero units. Under 8 minutes of face-to-face time, the MNT codes don't apply.

What counts as billable time (and what doesn't)

The minutes you count are face-to-face MNT time: direct, live interaction with the patient, in person or over telehealth video. That includes the assessment conversation, nutrition education, reviewing the plan together, and answering the patient's questions during the visit.

What does not count:

• Charting after the visit. Your 20 minutes of note-writing is real work, but it isn't billable time under 97802/97803.
• Scheduling, reminders, and phone tag.
• Reviewing labs or the referral before the session.
• Time the patient spends in the waiting room or fixing their video connection.
• Non-MNT chit-chat — a few minutes of rapport is normal clinical care, but a 20-minute tangent isn't therapy time.

This is also the honest argument for shrinking your documentation burden: every minute of charting is unbillable by definition, so the less time notes take, the better your effective hourly rate. That's the whole premise behind AI charting.

Documentation that supports your units

If a payer audits, the question is simple: does the note support the units on the claim? Make it unambiguous:

• Record time in every note — either start/stop times ("2:03–2:58 pm") or total face-to-face minutes ("55 minutes face-to-face MNT").
• Make the content match the duration. A 4-unit note with two sentences of intervention looks wrong even if the timestamp is right. Your charting should demonstrate medical necessity for the time spent.
• Match the claim to the note before it goes out. Units on line 24G of the claim, minutes in the note — same number of units, every time.

The under-billing problem nobody audits you for

Payers audit over-billing. Nobody audits under-billing — which is why it's the most common and most invisible revenue leak in nutrition practices. It usually looks like one of these:

• Fear-based rounding down. A 55-minute session billed as 3 units "so nothing gets questioned." The table says 4. Billing accurately isn't aggressive; it's correct.
• Flat-billing every visit at 2 or 3 units regardless of actual length, because that's what a course or a colleague once said was "standard."
• Not billing short encounters at all, when 8+ minutes is a legitimate unit.
• Forgetting the table's edges — treating 38 minutes as 2 units, or 53 as 3.

Run the math on your own schedule: one forfeited unit per day, five days a week, at the per-unit rates in your fee schedules, compounds into a four-figure annual loss for a solo practice — often more. The fix costs nothing: document your minutes, apply the table, bill what you earned.

A 30-second unit-counting workflow

1. Note face-to-face start and stop times during or immediately after the visit.
2. Convert with the table (or let software convert automatically).
3. Check the payer's per-visit and per-year unit caps.
4. Confirm claim units match documented minutes.
5. Submit.

That's the whole rule. No guessing, no defensive rounding, no leaks.

How Alva helps: Alva counts your units from the actual recorded session time, writes the note with face-to-face minutes documented, and validates the claim against payer unit caps before submission — so you bill every unit you earned, defensibly, for $99/month. Start a 7-day free trial.