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Patient Volume

Each provider applying for a Medicaid EHR incentive payment must demonstrate patient volume thresholds for each year of program participation. PLEASE NOTE that CMS Rules do not allow recycling eligibility criteria in subsequent Program Years. This means providers cannot re-use or overlap any dates of a patient volume 90-day time period from a previous Program Year attestation.

The PIP/EHRIP Team receives many questions around selecting the correct 90-day Patient Volume time period. We have listed the most frequently found issues below with links to the individual descriptions and solutions.

The CMS Definition of Medicaid Encounter

A  patient encounter is any service rendered to an individual on any one day.

Medicaid encounter is any service rendered to an individual on any one day where:

  • Medicaid paid for part or all of the service,
  • Medicaid paid all or part of the individual's premiums, co-payments, and cost-sharing, or
  • The individual was enrolled in a Medicaid program at the time the billable service was provided.
  • For FQHCs allowed to include Needy encounters in their patient volume calculation, services rendered on any one day to an individual can be counted if:
    • The services were furnished at no cost;
    • The services were paid for at a reduced cost based on a sliding scale determined by the individual's ability to pay.

To calculate Medicaid patient volume, an EP must divide:

The total Medicaid encounters in any representative, continuous 90-day period (M90) by

The total for all patient encounters in the same 90-day period.  (A90)

M90 ÷ A90 = Patient Volume

FQHCs calculate patient volume by adding Needy encounters in the same 90-day period (N90):

(M90 + N90) ÷ A90 = FQHC Patient Volume


Avoid this common error when calculating patient volume

DO NOT COUNT multiple claims for services for the same patient by the same provider on the same day. Please keep in mind that the patient volume calculation assesses ENCOUNTERS, not claims, and requires the provider to remove duplicate encounters on the same day for both the numerator (M90) and denominator (A90).

Services rendered to the same patient by different providers on the same day are allowed to be counted discretely by each provider.

Do Not Overlap Dates When Assessing Patient Volume

CMS Rules do not allow recycling eligibility criteria from previous Program Years. This means providers cannot re-use or overlap any dates of a patient volume 90-day time period from a previous Program Year attestation.

Group Patient Volume

Eligible Professionals may use a clinic or group practice's patient volume as a proxy for their own under three conditions:

  1. The clinic or group practice's patient volume is appropriate as a patient volume methodology calculation for the EP (for example, if an EP only sees Medicare, commercial, or self-pay patients, this is not an appropriate calculation);
  2. There is an auditable data source to support the clinic's patient volume determination; and
  3. So long as the practice and EPs decide to use one methodology in each year.

For each provider attesting with Group Patient Volume, the Group Definition must be provided at the time of attestation. The Group Definition must contain:

  • The complete set of Billing NPIs defining the Group, and
  • A complete list of individual provider names and individual NPIs for all attending or rendering providers associated with the group, regardless of whether they are Eligible Professionals attesting for an incentive payment.

The calculation/compilation of the Group Patient Volume must incorporate ALL encounters under the practice’s set of billing NPIs. If attending providers are not attesting for a PIP/EHR Incentive Program payment, their encounters must still be included in the numerator and denominator of the Group Patient Volume calculation.

Additional guidance on Group Patient Volume is available in the CMS FAQ 2993.

EP 90-Day Patient Volume Reporting Period Options

Some of the most common questions we receive involve the correct selection and reporting of the 90-Day Patient Volume Reporting Period. As shown in the MAPIR screens, there are two options for selecting the 90-day period:

Calendar Year Preceding Payment Year
12 Months Preceding Attestation Date

Entering a start date that violates the rules of your 90-day Patient Volume period option will produce an error message: (“* The date that you have specified is invalid)and you will not be able to proceed with your application.

To avoid this confusion, consult this updated guideline illustrating how to select the right 90-day Patient Volume period: Patient Volume Reporting Period Options.

IMPORTANT: The Patient Volume 90-Day period for an individual practitioner or any member of a Group Patient Volume Definition cannot overlap a previous Program Year 90-Day Patient Volume Period.  CMS Rules do not allow recycling eligibility criteria in subsequent Program Years, e.g., re-using all or part of a patient volume period from a previous Program Year attestation.

EP Patient Volume Tool

Guidance and a template for compiling the necessary data in the required formats during the attestation process. It is strongly recommended that the Patient Volume Tool be uploaded with each provider's attestation.

Rule References for Medicaid PIP/EHRIP Patient Volume Requirements

This document contains excerpts from the official Final Rules establishing the EHR Incentive Program provide definitive guidance for calculating Medicaid patient volume:

Medicaid EHRIP Patient Volume Rule References   (PDF, 415 kb)

For questions, contact the Vermont PIP/EHRIP Team at

Back to the Vermont Medicaid PIP/EHRIP Home Page

(Page last updated 04/16/2021)