Whether you’re just starting out as a Medicare provider—or you’re making the switch from inpatient to outpatient—there’s a lot to keep straight when it comes to the complicated rules, regulations, and policies that govern Original Medicare (which consists of both Part A and Part B). But if you want to receive reimbursement for your services, you’ve got to know how to navigate the murky Medicare waters. So, what does Medicare Part A cover—and what do you need to know about Part A eligibility? How about Part B? And what’s with all those G-codes and modifiers? Good questions—and luckily for you, we’ve got answers. Let’s dive in.

(For even more answers to tricky Medicare questions, be sure to check out this PT billing FAQ.)

Part A Rehab Therapy Billing

Medicare Part A—a.k.a hospital insurance—helps cover inpatient medical care, including care provided in critical access hospitals, skilled nursing facilities, and, in some cases, at home. Most individuals receive Medicare Part A coverage with no premium when they turn 65—although, in many cases, there is a deductible ($1,288 each benefit period in 2016) and coinsurance—because either the beneficiary or his or her spouse paid enough Medicare taxes while working. While Part A and Part B billing guidelines do share some common ground, there are a handful of notable exceptions. Here a few:


In compliance with the Balanced Budget Act of 1997, Medicare consolidates payments for most services provided in a Medicare-covered skilled nursing facility (SNF) into a bundle, which it then pays the SNF. That means that providers in SNFs must bill Medicare—specifically, their Part A Medicare Administrative Contractor—in a consolidated bill, because the SNF is then responsible for billing the “entire package of care that residents receive during a covered Part A SNF stay and physical, occupational, and speech therapy services received during a non-covered stay.” For more information, check out this CMS page or this one.

Treatment Only

In this post, WebPT’s Brooke Andrus points out that according to Pauline Watts, MCSP, PT, and Danna D. Mullins, MHS, PT—the authors of this Advance article—therapists who bill under Medicare part A in an SNF are not allowed to bill for the “time it takes to perform the formal initial evaluation and develop the treatment goals.” Furthermore, “the plan of treatment cannot be counted as minutes of therapy received by the beneficiary.” Per the Federal Register, “Time starts when [the provider] begins the first treatment activity or task and ends when he finishes with the last apparatus and the treatment is ended.” According to Watts and Mullins, “this certainly does not appear to include care plan meetings, discussions with the physician and other staff, obtaining orders, discharge planning, documenting the patient’s refusal of treatment, etc.”


When two therapists of different disciplines determine that a patient will better progress toward his or her goals if the clinicians provide their respective interventions during the same session, then co-treatment may be appropriate. For co-treatment scenarios involving Part A beneficiaries, each therapist may bill the full treatment session with that patient. As always, therapists must adhere to all policies regarding mode, modalities, and supervision as well as all other federal, state, practice, and facility policies. For more information, check out this resource from the American Speech-Language-Hearing Association (ASHA), American Occupational Therapy Association (AOTA), and American Physical Therapy Association (APTA). You can also learn more about co-treatment in our Definitive Guide to Medicare.


Home Care: According to Pauline M. Franko, MCSP, PT, and Danna D. Mullins, MHS, PT—the authors of this Advance article—each Medicare Part A-covered at-home physical therapy session should last about 48 minutes.

Inpatient Rehab Facility: For a patient to qualify for inpatient therapy at an inpatient rehab facility, that patient should need at least 15 hours of therapy—in at least two therapy disciplines—each week.

SNF: Franko and Mullins explain that in an SNF, patients receive “skilled, medically necessary services” to address the same conditions they were treated for in the hospital. Each clinician determines the total number of minutes he or she believes accurately represents the duration of his or her services for that particular patient over the course of a given timeframe. This number dictates which specific resource utilization group (RUG) category the patient falls into. “Once the patient has been placed in a RUG category, Medicare expects that the facility will provide the appropriate amount of therapy that the patient needs,” they said. “This can change throughout the period of care, sometimes being more minutes of time than the current RUG level, sometimes being less.”

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Part B Rehab Therapy Billing

Medicare Part B—a.k.a. medical insurance—helps cover medically necessary or preventive outpatient services. Such services include lab tests; surgeries; doctor visits; and physical, occupational, and speech therapy treatment. As with Part A, individuals become eligible to receive Medicare Part B insurance at age 65—or younger in cases of disability and end-stage renal failure. Unlike Part A, most people pay a monthly premium ($104.90 in 2016) for Part B. Then, once a patient meets his or her deductible ($166 this year), he or she will “typically pay 20% of the Medicare-approved amount for most doctor services…outpatient therapy, and durable medical equipment.” So far, so good, right? Now let’s get into the tricky stuff:

8-Minute Rule (and Timed/Untimed Codes)

To receive Medicare Part B payment for a time-based—a.k.a constant attendance—code, a rehab therapist must provide direct treatment for at least eight minutes. What’s a time-based code? Unlike untimed codes (e.g., those that account for services such as completing evaluations or reevaluations, applying hot or cold packs, and performing unattended electrical stimulation), timed codes allow for variable billing in 15-minute increments. These include the codes for one-on-one services like therapeutic exercise, manual therapy, and gait training.

According to this 8-Minute Rule Guide, “When calculating the number of billable units for a particular date of service, Medicare adds up the total minutes of skilled, one-on-one therapy and divides that total by 15. If eight or more minutes are left over, you can bill for one more unit; if seven or fewer minutes remain, you cannot bill an additional unit.” Check out the guide in full for an 8-minute rule reference chart, scenario-based examples, and advice on how to handle mixed remainders.

Functional Limitation Reporting (and G-codes)

As of July 1, 2013, all physical, occupational, and speech therapists must complete functional limitation reporting (FLR) for all Medicare Part B patients in order to receive reimbursement for their services. To do so successfully, therapists must document each patient’s primary functional limitation, the severity of that limitation, and the patient’s therapy goals—at the initial evaluation or re-evaluation (if applicable), at minimum every ten visits (in the form of a progress note), and at discharge. To submit this data, therapists must use G-codes, corresponding severity modifiers, and therapy modifiers. For everything you need to know about FLR, check out this guide or this entire site.

Now, FLR isn’t the only Medicare reporting initiative that uses G-codes; Physician Quality Reporting System (PQRS) does, too. However, PQRS and FLR are completely separate programs—despite the fact that both require the submission of quality data codes. To learn more about G-codes—the FLR ones and the PQRS ones—check out this guide to G-codes.


Under Part B, if two therapists of the same or different discipline(s) determine that it’s in a patient’s best interest to receive treatment from both therapists at the same time, then neither therapist can bill separately for the full session. That means that the combined time the therapists bill should be equal to the total duration of the treatment session. This can be achieved in one of two ways:

  1. one therapist can bill for the entire session, while the other bills nothing; or
  2. The two therapists can split the billed units.

It’s important to note, though, that when one of the treating therapists is a speech therapist, the guidelines are slightly different. According to this ASHA article, “Because SLPs usually bill treatment codes that represent a session (rather than an amount of time), and because Medicare has no published minimum/maximum session length, the SLP would bill for one untimed session.” If the SLP is working with an OT or PT, then the OT or PT would then bill “the timed treatment codes for the occupational or physical therapy.” To learn more about co-treatment, check out this resource or this guide.

Therapy Cap (and KX Modifier)

As of February 9, 2018, Medicare no longer places a cap on physical therapy, occupational therapy, or speech-language pathology services. However, therapists should continue applying the KX modifier to any claims exceeding the $2,010 threshold for both occupational therapy as well as physical and speech therapy (combined). Furthermore, all claims exceeding the $3,000 threshold are subject to a targeted review process. To learn more, refer to the last section of this post.