Insurance Billing

CPT Codes for Dietitians: 97802, 97803, and 97804 Explained

The three MNT CPT codes every registered dietitian needs, how time-based units work, which ICD-10 codes to pair them with, and the payer quirks that cause denials.

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

If you bill insurance as a registered dietitian, virtually all of your revenue flows through three CPT codes. Getting them right — the right code, the right units, the right diagnosis pairing — is the difference between getting paid in two weeks and chasing a denial for two months.

This guide covers what each code means, how time-based units actually work, and the payer-specific quirks that cause most preventable denials.

The three MNT CPT codes

Medical Nutrition Therapy (MNT) services are reported with CPT codes 97802, 97803, and 97804:

Three details matter more than anything else:

1. 97802 is (almost always) once per patient. It represents the initial assessment. Bill it on the first visit, then switch to 97803 for every visit after that. Billing 97802 twice for the same patient is one of the most common — and most avoidable — denial triggers.
2. These are time-based codes. You don't bill "a session"; you bill units of time. More on that below.
3. They are face-to-face codes. The time you count is direct patient contact (in person or via telehealth video), not charting time afterward.

How units work (and how to count them)

97802 and 97803 are billed in 15-minute units. Most payers follow CMS's "8-minute rule" logic for time-based codes: you can bill a unit once you've crossed the midpoint of that unit.

So a standard 60-minute initial assessment is typically 97802 × 4 units, and a 30-minute follow-up is 97803 × 2 units.

Two cautions:

• Your note must support your units. If you bill 4 units, your documentation should show ~53+ minutes of face-to-face time. Session time that doesn't match billed units is low-hanging fruit for payer audits and recoupments.
• Commercial payers can differ. Some plans cap units per visit (e.g., 4 units max) or per year. Check the payer's MNT policy — or better, verify benefits before the first appointment.

ICD-10 codes: what to pair with your CPT codes

The CPT code says what you did; the ICD-10 code says why. Payers deny claims when the "why" doesn't match their coverage policy. The codes dietitians use most:

The Z71.3 warning: not every payer reimburses Z71.3 as a primary diagnosis. Some large commercial payers' policies exclude it outright or require a medical diagnosis in the primary position instead. Before you build your superbills and claim templates around Z71.3, confirm each payer's policy — this single mismatch quietly generates a huge share of nutrition claim denials. (Payer policies also change; recheck yearly.)

A safe general pattern: primary = the medical condition driving the referral (e.g., E11.9), secondary = Z71.3 and/or the BMI code when applicable — unless the payer's preventive-benefit policy specifically wants Z71.3 first.

Medicare's rules are their own thing

Medicare Part B covers MNT only for specific conditions:

• Diabetes (type 1 or 2)
• Chronic kidney disease (non-dialysis)
• Post-kidney-transplant (within 36 months)

Coverage is 3 hours of MNT in the first calendar year and 2 hours in each subsequent year, and it requires a physician referral. For additional hours after a change in condition, Medicare uses G-codes G0270/G0271 rather than the standard CPT codes. If most of your caseload is commercial insurance, you may never touch the G-codes — but don't bill Medicare on autopilot with commercial habits.

Beyond MNT codes: 99401–99404

Some commercial payers reimburse dietitians under preventive medicine counseling codes (99401–99404, in 15/30/45/60-minute versions) instead of — or alongside — the MNT codes, typically for preventive visits billed with Z71.3. Whether you can use them depends entirely on your contract and the payer's policy. If a payer denies 97802/97803 for a preventive-intent visit, this family is the first alternative to investigate.

Telehealth: modifiers and place of service

MNT codes are widely covered via telehealth, but claims need to say so correctly:

• Modifier 95 on the CPT line (some payers use GT).
• Place of service: POS 10 (telehealth, patient at home) or POS 02 (telehealth, other location) — payers differ on which they want.
• Some payers reimburse telehealth MNT at parity with in-person; others don't.

A telehealth claim submitted with an in-person POS (11) — or vice versa — is another classic silent denial.

The five denial triggers to check before submitting

1. 97802 billed for an established patient → use 97803.
2. Units don't match documented time → recount with the midpoint rule.
3. Diagnosis not covered by the payer's MNT/preventive policy → check whether the payer accepts Z71.3 as primary, requires a medical diagnosis, or requires a BMI code.
4. Missing or wrong telehealth modifier/POS combination.
5. Eligibility problems — the patient's plan simply doesn't include nutrition benefits, or has a visit cap you've hit. Verifying benefits before the first session prevents this whole category.

Every one of these is checkable before the claim goes out. That's the real lesson of MNT billing: denials are mostly predictable, which means they're mostly preventable — either with a rigorous pre-submission checklist or with software that validates claims automatically.

How Alva helps: Alva generates the billing codes from your session itself — units from actual session time, diagnosis pairings validated against payer rules — and submits the claim for you, flagging problems before the payer ever sees them.