Complete Billing Guide for CPT Code 97811: Time Rules, Modifiers & Reimbursement (2026 Update)

Here's something that happens in nutrition therapy practices more often than it should a dietitian spends 45 minutes with a diabetic patient, documents the session thoroughly, and the billing team submits the claim. It comes back denied. Not because the service wasn't covered. Not because the patient wasn't eligible. But because someone billed 97811 without the required primary code sitting alongside it, or counted units in a way the documentation simply didn't support.

That's not a hypothetical. Our team sees variations of that scenario regularly when we review MNT billing workflows for new clients. And the frustrating part is that it's entirely preventable.

CPT code 97811 is one of those codes that looks simple until you're actually in the weeds of billing it correctly. It's time-based. It's an add-on code. It has specific documentation requirements, modifier considerations, and payer rules that shift depending on whether you're dealing with Medicare, Medicaid, or a commercial plan. Get those details right, and the code performs well. Miss one piece, and you're looking at denials, rework, and potential compliance exposure down the road.

This guide covers everything your billing team, coders, and practice managers need to know about CPT 97811 in 2026 written from real experience working with practices that bill these codes every day.

CPT 97811 is the code for Medical Nutrition Therapy (MNT) — individual, face-to-face with the patient, each additional 15 minutes.

The phrase "each additional 15 minutes" is the most important part of that definition. This is an add-on code, which means it only exists to extend the time captured by a primary MNT code. It cannot be submitted on its own. Ever. If 97811 appears on a claim without either CPT 97802 or CPT 97803 alongside it, that claim will reject and rightfully so, because the code has no standalone meaning.

Here's how the three MNT codes relate to each other:

CPT 97802 is used for the initial MNT assessment and intervention the first time a patient is seen for a formal nutrition therapy evaluation. It's billed in 15-minute increments.

CPT 97803 covers MNT re-assessment and intervention every follow-up session after the initial evaluation. Also billed in 15-minute increments.

CPT 97811 picks up where 97802 or 97803 leaves off. When a session runs longer than 15 minutes, 97811 captures those additional increments of time, each representing another 15 minutes of face-to-face nutrition therapy.

As for who bills these codes the answer is primarily Registered Dietitians (RDs) and Registered Dietitian Nutritionists (RDNs). For Medicare specifically, the provider must meet the definition of a "registered dietitian or nutrition professional" as outlined in Medicare statute. Other payers may have broader or narrower credentialing requirements, so it's worth confirming provider eligibility with each plan before billing.

Because 97811 is a time-based code, every billing decision flows from one question: how many minutes of face-to-face time actually happened during this session?

The structure works like this. The primary code either 97802 or 97803 captures the first 15 minutes. From there, each additional 15-minute block is billed as one unit of 97811. The question that comes up constantly is what happens when time doesn't divide evenly into 15-minute chunks.

The rounding rule most payers follow is the "midpoint" standard: if you've completed at least 8 minutes into the next 15-minute increment, you can count that increment and bill for the unit. If you're under 8 minutes, you can't.

This is where a lot of practices quietly overbill without realizing it — not intentionally, but because no one ran the actual numbers.

Let's walk through some concrete examples:

Example 1 — 30-minute initial session: A dietitian completes a first-time assessment with a new patient. Total face-to-face time is exactly 30 minutes. Correct coding: 97802 x1 + 97811 x1 The first 15 minutes go to 97802. The second 15 minutes are captured by one unit of 97811.

Example 2 — 52-minute re-assessment: A follow-up session runs 52 minutes total.

97803 covers the first 15 minutes
97811 x1 covers minutes 16–30
97811 x2 covers minutes 31–45
That leaves 7 minutes remaining which falls short of the 8-minute midpoint threshold

Correct coding: 97803 x1 + 97811 x2 Billing a third unit of 97811 here would be unsupported and creates audit exposure.

Example 3 — 53-minute re-assessment: Same scenario, just one minute longer. Now the remaining time after 45 minutes is 8 minutes which meets the threshold. Correct coding: 97803 x1 + 97811 x3 That single extra minute is the difference between two and three units being billable.

One more thing worth emphasizing: the time that counts is face-to-face time with the patient only. Documenting afterward, reviewing labs before the session, or calling the referring provider doesn't count toward billable MNT time. If your documentation doesn't make that distinction clear, payers during an audit won't give you the benefit of the doubt.

The documentation supporting a CPT 97811 claim has to do more than prove the session happened. It has to prove the session lasted as long as you billed, that it was medically necessary, and that the clinical content matches the diagnosis and goals being addressed.

Here's what a complete, compliant MNT session note should include:

Documented time. Start time and stop time, or a clear statement of total face-to-face minutes. "Patient seen for nutrition counseling" doesn't tell a payer or auditor anything about time. "Session began at 10:00 AM and concluded at 10:45 AM" does.

Primary diagnosis. The condition driving the need for MNT should be clear. Common diagnoses include Type 2 diabetes (E11.x), chronic kidney disease (N18.x), obesity (E66.x), hyperlipidemia (E78.x), and hypertension (I10). The diagnosis on the claim should match what's in the note.

Assessment findings. Current dietary intake, weight and BMI, relevant lab values, medical history affecting nutrition these aren't just nice to have. They're what justifies the service as medically necessary rather than general wellness advice.

What was actually covered in the session. "Nutrition education provided" is the kind of vague documentation that makes auditors dig deeper. Specific entries like "reviewed carbohydrate counting technique, discussed portion estimation for common foods, addressed patient's confusion regarding low-glycemic food choices" tell the story of a real clinical encounter.

Patient response and engagement. Did the patient understand the material? Are there barriers to following through cost, family habits, cultural considerations? What goals did the patient agree to work toward?

Plan for next visit. What's being followed up on? When is the next session scheduled?

Referring provider information. For Medicare claims, this is not optional. A physician or qualified non-physician practitioner must have referred the patient for MNT, and that referral with the referring provider's name and NPI needs to be on the claim.

The documentation mistakes that most reliably cause denials are: missing or ambiguous time entries, notes that look copy-pasted from a previous visit, no documented clinical rationale for the number of units billed, and missing referral information on Medicare claims.

Modifiers exist to communicate context. They tell the payer something about how a service was delivered that the code alone doesn't capture. For CPT 97811, three modifiers come up most frequently.

Modifier 25 — Significant, Separately Identifiable E/M Service

Modifier 25 is appended to an evaluation and management code when a provider performs a significant, separately identifiable E/M service on the same day as another procedure or therapeutic service.

In the context of MNT billing, this comes up when a patient sees both a physician (for an E/M visit) and the dietitian (for MNT) on the same day. The modifier communicates to the payer that these were two distinct clinical services not a single visit that's being double-billed.

Where the modifier goes: On the E/M code. Not on 97802, 97803, or 97811.

This is one of the most consistently misapplied modifiers in MNT billing. When it's placed on the wrong code, the claim often denies or processes incorrectly.

Example: A patient with CKD has a nephrology appointment in the morning. The practice's dietitian sees the same patient afterward for a 30-minute MNT re-assessment. The claim would include the appropriate E/M code with modifier 25, plus 97803 x1 and 97811 x1. The MNT codes carry no modifier.

Modifier 59 — Distinct Procedural Service (and the X Modifiers)

Modifier 59 signals that a service was distinct and separate from other services billed on the same date, even though standard billing edits might otherwise bundle them together.

In MNT billing, this occasionally comes up when 97811 is billed alongside other therapeutic or evaluation codes and the payer's editing system flags them as duplicate or overlapping. Modifier 59 or one of the more specific X modifiers for Medicare clarifies that the services were clinically separate.

For Medicare claims, CMS prefers the more precise X modifier variants:

XE — Separate encounter
XP — Separate practitioner
XS — Separate structure (anatomically distinct)
XU — Unusual non-overlapping service

For MNT-specific situations, XU is typically the most applicable when the therapy is clinically distinct from another same-day service that doesn't fall into the other X categories.

One important caution: modifier 59 and its X variants are not denial-fix tools. Using them without proper documentation to support that the services were genuinely distinct is a compliance risk, not a solution.

Modifier 52 — Reduced Services

When a session is cut short patient fatigue, unexpected scheduling conflict, clinical reason that ends the encounter early and the documented time doesn't support the originally planned billing, modifier 52 communicates that the service was reduced.

This modifier protects both the practice and the claim. It's far better to bill accurately with modifier 52 than to submit full units the documentation can't support, or to write off the service entirely.

Reimbursement for CPT 97811 varies enough across payer types that applying a single expectation to all of them leads to revenue surprises. Here's how the major payer categories break down.

Medicare:

Medicare covers MNT including CPT 97811 for beneficiaries with Type 2 diabetes, non-dialysis kidney disease, or those within 36 months of a kidney transplant. The annual benefit is structured as 3 hours in the initial year and 2 hours in subsequent years. Additional hours may be covered if a physician documents a change in the patient's condition requiring more intensive nutrition therapy.

For 2026, Medicare's reimbursement for CPT 97811 per unit generally falls in the $25–$35 range, varying by geographic locality under the Medicare Physician Fee Schedule. Providers should check the current MPFS rates through the CMS fee schedule lookup tool, as these are updated each January.

The physician referral requirement for Medicare MNT is absolute. No referral on file means denial no matter how well-documented the session is.

Medicaid:

Medicaid MNT coverage is entirely state-specific. Some state programs cover 97811 under chronic disease management benefits. Others don't include MNT at all. Before billing Medicaid for nutrition therapy services, confirm your state's current policy, covered diagnoses, and any prior authorization requirements. Don't assume that what was covered last year still applies Medicaid policies update frequently.

Commercial Payers:

Most major commercial insurers cover MNT for conditions including diabetes, cardiovascular disease, obesity, and renal disease — largely due to ACA preventive services requirements. Annual visit limits commonly fall somewhere between 6 and 12 encounters, though how "visit" is defined varies. Some payers count units, others count dates of service. That distinction matters considerably for a code like 97811.

Verify benefits at the start of each plan year and at the start of each patient's benefit year, which often doesn't align with the calendar year. Coverage that was in place in 2025 may have been restructured when the plan renewed.

Telehealth note for 2026: Practices that shifted MNT services to telehealth during or after the pandemic should confirm current coverage and billing requirements for remote MNT services. The rules around place-of-service codes and telehealth-specific modifiers for MNT vary by payer, and CMS continues to refine its telehealth policies annually.

Some billing mistakes happen because the rules are genuinely complex. Others happen because a workflow hasn't been updated in a while and nobody caught it. These are the most frequent 97811 errors our team encounters:

Submitting 97811 without a primary MNT code. This causes an automatic reject. 97811 has no meaning without 97802 or 97803 on the same claim.

Unit count that doesn't match documented time. Three units of 97811 on a 35-minute session note is a compliance problem waiting to be found. Run the math before you bill.

Missing referral on Medicare claims. This is a hard denial, not a soft one. The referral must exist, be documented, and be reflected on the claim.

Modifier 25 on the wrong code. It goes on the E/M, not on the MNT code. Every time.

Billing beyond the annual benefit limit without authorization. If a payer covers 8 MNT visits per year and the patient is on visit 9, that claim will deny unless prior authorization for additional visits was obtained and documented before the session.

Session notes that don't reflect actual clinical content. Notes that appear templated, lack patient-specific detail, or describe time in general terms without face-to-face specification are audit vulnerabilities even on claims that initially pay.

Practical audit prep habit: Pull 10 to 15 CPT 97811 claims per month and match billed units against documented session time for each one. This single check catches the majority of time-based billing errors before they accumulate into a pattern that draws payer attention.

Scenario 1: Initial MNT Session, New Diabetic Patient, 45 Minutes

A primary care physician refers a patient newly diagnosed with Type 2 diabetes (E11.9) to the practice's RD for medical nutrition therapy. The dietitian conducts a thorough initial assessment reviewing diet history, lab values, and lifestyle factors followed by education on carbohydrate management and glycemic response. Session start time: 9:00 AM. End time: 9:45 AM. Total face-to-face time: 45 minutes.

Correct claim:

97802 x1 (first 15 minutes)
97811 x2 (additional 30 minutes)
Diagnosis: E11.9
Referring provider NPI: documented on claim

What could go wrong: If the documentation says "45-minute nutrition session" without distinguishing face-to-face time from documentation time, a Medicare auditor could challenge whether all 45 minutes qualify. Always specify that documented time was face-to-face patient time.

Scenario 2: Re-Assessment with Same-Day Physician Visit, 30 Minutes MNT

A patient with Stage 3 CKD (N18.3) has a scheduled nephrology appointment. Following the physician's E/M visit, the in-practice RD provides a 30-minute MNT re-assessment session. Start time and stop time are documented in the nutrition note.

Correct claim:

Appropriate E/M code with modifier 25 (physician visit)
97803 x1 (first 15 minutes of MNT)
97811 x1 (additional 15 minutes of MNT)
Diagnosis: N18.3

What could go wrong: If modifier 25 is omitted from the E/M code, the payer may bundle the E/M and MNT services and reimburse only one. If the MNT re-assessment note doesn't reflect updated clinical findings distinct from the physician's E/M documentation, the payer may question whether these were genuinely two separate services.

Wrapping It All Up

CPT 97811 isn't a difficult code conceptually. What makes it challenging is the layered set of requirements around it the add-on structure, the time calculations, the documentation specificity, the modifier precision, and the payer variability that makes a single approach unreliable across your full payer mix.

The practices that bill this code cleanly share a few things in common. They document time in a way that's unambiguous. They train clinical staff to capture what actually happened in a session, not just that a session happened. They verify payer-specific rules rather than assuming universal coverage. And they audit their own claims regularly enough to catch problems before payers do.

Revenue cycle integrity for MNT services doesn't require heroic effort it requires structured, consistent habits applied across every session and every claim.

Free Demo