Physical Therapy Invoice: PT Superbill and the 8-Minute Rule

Quick answer: A physical therapy invoice lists the clinic and patient details, a unique invoice number, each date of service, every CPT code with its units and treatment minutes, the fee, any discount, payments received and the balance due. Count timed codes with the 8-minute rule (8 to 22 minutes is one unit), and add ICD-10 codes, NPI and tax ID so the invoice works as a PT superbill.

Physical therapy billing turns minutes into money. The difference between a two-unit and three-unit visit is a few minutes on the clock, and payers check that your units match your notes. A clear physical therapy invoice template shows the codes, units and minutes so patients, insurers and auditors can follow it. You can build one with our free invoice generator and download a PDF in minutes.

This guide covers what a PT invoice must include, the common CPT codes, how the 8-minute rule works with a worked calculation, the 2026 Medicare thresholds, how to give cash-pay patients a PT superbill, and a sample invoice with real arithmetic. It applies to outpatient clinics, mobile and home-visit therapists, and cash-based practices.

What a physical therapy invoice should include

• Provider details: clinic or therapist name, address, phone, logo, NPI and tax ID.
• Patient details: name, date of birth or account number, and the responsible party if someone else pays.
• Invoice number and date: sequential and unique, for example PT-2026-0518. Use our invoice number generator to choose a format.
• Dates of service: each visit on its own lines.
• CPT codes, units and minutes: list total timed minutes per visit so the units can be checked.
• Diagnosis codes: ICD-10 codes when the patient will seek reimbursement.
• Fees, discounts and payments: fee per line, package discounts, amounts paid and balance.
• Terms: due date, payment methods, and late cancellation or no-show policy.

Common physical therapy CPT codes

PT codes fall into two groups. Service-based (untimed) codes are billed once per visit regardless of length. Timed codes are billed in 15-minute units. Mixing up the two is one of the most common billing errors.

CPT code	Service	Type
97161 / 97162 / 97163	PT evaluation, low / moderate / high complexity	Untimed, once per evaluation
97164	PT re-evaluation	Untimed
97110	Therapeutic exercise	Timed, 15-minute units
97112	Neuromuscular re-education	Timed, 15-minute units
97140	Manual therapy	Timed, 15-minute units
97530	Therapeutic activities	Timed, 15-minute units
97116	Gait training	Timed, 15-minute units
97014	Electrical stimulation, unattended	Untimed (Medicare uses a G code)

Pair each code with a plain description on the patient copy, such as "Therapeutic exercise (97110), 2 units". Patients and HSA administrators understand words, while insurers need the codes.

The 8-minute rule explained

The 8-minute rule is how Medicare converts direct, one-on-one treatment time into units for timed codes. Add up all timed minutes for the visit, divide by 15, and if 8 or more minutes remain, bill one more unit. Untimed services such as evaluations do not count toward the total.

Total timed minutes	Billable units
Fewer than 8	0
8 to 22	1
23 to 37	2
38 to 52	3
53 to 67	4
68 to 82	5

Worked 8-minute rule calculation

A patient receives 23 minutes of therapeutic exercise (97110), 10 minutes of manual therapy (97140) and 7 minutes of neuromuscular re-education (97112). Total timed minutes are 23 + 10 + 7 = 40, which falls in the 38 to 52 band, so the visit supports 3 units.

Next, assign the units. 97110 has one full 15-minute unit, leaving 8 minutes. The remaining minutes are 8 (97110), 10 (97140) and 7 (97112). Two units are left to assign, and they go to the codes with the most remaining minutes: 97140 (10) and 97110 (8). The invoice shows 97110 x 2 and 97140 x 1. The 7 minutes of 97112 are documented in the notes but not billed as a separate unit.

Two practical habits make the 8-minute rule easier to defend. First, record start and stop times or total minutes for each timed code in the daily note, not just the units. Second, record total timed minutes and total treatment time for the visit, so anyone checking the claim can repeat your calculation. If the minutes in the note do not support the units on the invoice, reduce the units rather than hoping nobody checks.

Some commercial payers follow a different approach that counts each code on its own. Bill the way each payer's policy requires, and always keep minutes per code in your treatment notes.

2026 Medicare thresholds for therapy

Medicare no longer caps outpatient therapy, but it uses thresholds that affect how you bill. According to the CMS therapy services page, as of 2026:

• The KX modifier threshold is $2,480 for physical therapy and speech-language pathology combined, and a separate $2,480 for occupational therapy.
• Claims above the threshold need the KX modifier, which confirms the care is medically necessary and documented. Without it, they are denied.
• A targeted medical review threshold of $3,000 applies, at which claims may be reviewed.
• Services furnished in whole or in part by a physical therapist assistant carry the CQ modifier alongside the GP modifier, and Medicare pays them at a reduced rate.

For example, if a patient's allowed therapy charges reach $2,350 by mid-year and the next visit adds $160, the running total becomes $2,510, which is above the $2,480 threshold. That visit and later ones need the KX modifier, supported by notes showing why continued therapy is medically necessary.

For Medicare patients, keep a running total of allowed charges for the year in your notes or on statements, so you know when the KX modifier is needed. Medicare also requires a plan of care certified by a physician or other qualified practitioner, even though patients can usually see a PT directly.

Direct access, cash-based PT and the PT superbill

The American Physical Therapy Association reports that, as of July 2025, all 50 states, Washington DC and the US Virgin Islands offer some form of direct access to physical therapist evaluation and treatment, though some states still attach conditions. That has helped cash-based practices grow: patients book directly, pay at the visit and, if they wish, claim out-of-network benefits.

Cash-based clinics usually price per evaluation and per follow-up session, often with packages. Prices vary too much by region and session length for a national average to be useful, so set yours from local competitors, visit length and your costs. Show packages on the invoice as a line item, record what was prepaid and give patients a written estimate before treatment. Our deposit invoice guide and partial payment invoice guide cover the layout.

PT superbill for out-of-network reimbursement

A PT superbill is a paid, itemized statement the patient sends to their own insurer. It adds what a plain receipt lacks: provider NPI and tax ID, patient date of birth, ICD-10 diagnosis codes, CPT codes with units, place of service, fees and amounts paid. Our superbill template guide covers every field and shows the reimbursement arithmetic, so use it as your reference. Many cash-based clinics issue one superbill per month listing every visit, which is easier for patients than one per session.

Each visit line on a PT superbill should carry enough detail for the insurer to price it. A typical line looks like this:

Date	CPT	Units	Timed minutes	ICD-10	Fee
Oct 13	97110	2	23	M54.50	$80.00
Oct 13	97140	1	10	M54.50	$40.00

The units follow the 8-minute rule example above, and the fees add up to the $120 session price the patient paid ($80 + $40). Matching the superbill lines to the invoice total in this way avoids awkward questions from insurers.

Because therapy received as medical treatment counts as a medical expense under IRS Publication 502, the same itemized receipt usually supports HSA or FSA reimbursement. Keep general fitness classes on separate lines, since they generally do not qualify.

Sample physical therapy invoice with real numbers

A cash-pay patient has an evaluation and five follow-up visits in October. The fees are illustrative; use your own fee schedule.

Date	Service	Qty	Rate	Amount
Oct 1	PT evaluation, moderate complexity (97162)	1	$160.00	$160.00
Oct 6 to 27	Follow-up session, 45 min (97110, 97140, 97112)	5	$120.00	$600.00
Subtotal				$760.00
Package discount (fixed)				-$40.00
Total				$720.00
Paid at visits				$480.00
Balance due				$240.00

The check: 5 x $120 = $600, plus $160 is $760. Less the $40 fixed discount, the total is $720. After $480 already paid, $240 is due. Treatment is not taxed, so tax stays at zero. In the generator, enter the two lines, choose a fixed $40 discount and type 480 in the amount paid field. For the superbill version, break each follow-up into its CPT codes and units using the 8-minute rule, and add diagnosis codes.

How to create a physical therapy invoice step by step

1. Open the invoice generator (or the UK version for physiotherapy practices billing in pounds) and add your practice details, NPI and tax ID.
2. Add the patient's name, account number and responsible party.
3. Set a unique invoice number, invoice date and due date.
4. List each date of service with CPT codes, units and timed minutes.
5. Check units against the 8-minute rule or the payer's own method before you finalise.
6. Apply any package or prompt-pay discount and record payments in the amount paid field.
7. Add notes with your cancellation policy and payment methods, then download and send the PDF securely.

The minimal template and ocean template give a clean clinical look.

Special physical therapy billing situations

A few situations account for most PT billing questions. Each one is easier to handle when the rule is written down before treatment and the invoice line explains itself.

Cancellations, no-shows and package refunds

A missed physical therapy visit costs a clinic the full appointment slot, so most cash-based practices set a written cancellation policy, such as 24 hours' notice or a fee. Show any fee on the invoice as a separate line with the date and reason, for example "Late cancellation, 15 Oct, per signed policy", and never give it a CPT code, because no treatment was provided.

Prepaid packages need clear refund terms. A common method is to charge visits already used at the full single-visit rate and refund the rest. For example, a patient who prepaid $550 for a five-visit package and used three visits at a $120 single rate would receive $550 minus $360, which is $190. Write the formula into your agreement before the patient pays, and show the arithmetic on the final statement. For Medicare patients, check current CMS guidance before charging missed appointment fees and apply the same policy to everyone.

Home visits, mobile PT and contracts with facilities

Mobile and home-visit therapists often charge a higher session rate or a separate travel fee to cover driving time. On the invoice, list the travel fee as its own line or in the extra field, so it is clear it is not a medical service; insurers and HSA administrators may treat it differently from treatment. If you contract with a skilled nursing facility, school, sports team or employer, the organisation is your client: invoice it for sessions or hours as your contract specifies, quote its purchase order or contract reference, and leave patient details off unless the agreement asks for them. Our guide to invoicing hourly work covers time-based contracts.

Common PT invoice mistakes

• Units that do not match minutes: billing 3 units for 35 minutes of timed care fails a basic check.
• Counting evaluation time as timed minutes: evaluations are untimed and stay out of the total.
• Missing the KX modifier: Medicare claims above $2,480 in 2026 are denied without it.
• Superbills without diagnosis codes: insurers return them unprocessed.
• Billing group time as one-on-one: group therapy has its own code (97150) and is not counted as one-on-one minutes.
• Travel fees with CPT codes: travel and cancellation fees are not treatment and should never carry a procedure code.

Related practices face similar issues: see our chiropractic invoice template, massage therapy invoice template and home health care invoice template.

This article is general information, not legal, tax or billing compliance advice. Confirm codes, thresholds and payer rules with CMS and your payer contracts.

Create your physical therapy invoice

A reliable physical therapy invoice shows codes, units and minutes that agree with your notes, keeps Medicare thresholds in view and gives cash-pay patients a PT superbill they can file. Build your next one in the free online invoice generator, download the PDF and keep a copy with the patient's billing record.