# Patient Acquisition & Retention Glossary | Fill The Lobby > 36 patient acquisition and retention terms in plain English, with formulas: acquisition cost, lifetime value, retention rate, no-show rate and more. *Source: https://fillthelobby.com/glossary* ## Patient acquisition & retention glossary The words, the formulas, and what they leave out. Plain definitions of the terms practice owners hear from agencies, software vendors and consultants, with the math written out so you can check anyone's numbers, ours included. 36 terms used in patient acquisition and patient retention for private and cash-pay practices, from patient acquisition cost and lifetime value to no-show rate, speed to lead and reactivation. Each entry opens with a one-sentence definition, then gives the formula where there is one. Written by Fill The Lobby, a patient acquisition and retention agency. ## Getting found and chosen. ### Patient acquisition The work of turning people who need what a practice offers into booked new patients: being found, being chosen and being booked. It covers search, ads, referrals and directories, and everything between an inquiry and a first appointment. See [patient acquisition strategies](https://fillthelobby.com/blog/patient-acquisition-strategies). ### Patient acquisition agency An agency that runs the path from a stranger's first search to their first visit, and is measured on booked appointments rather than clicks or leads. A patient acquisition and retention agency also runs what happens after that visit: rebooking, reminders, reviews and reactivation. Fill The Lobby is one; [here is what that involves](https://fillthelobby.com/patient-acquisition-agency). ### Search intent What the person typing a search is trying to get done. “Private pay therapist near me” and “what is CBT” share a subject and little else: one person is ready to book, the other is reading. Build each page and each ad group for one intent. ### Map pack The block of local results Google shows alongside a map for searches like “psychiatrist near me”. For most local healthcare searches it sits above the ordinary results, so it's worth winning on its own. Distance to the searcher is the part you can't change; the Google Business Profile, its categories and its reviews are the parts you can. See [healthcare SEO](https://fillthelobby.com/services/local-seo). ### Answer engine optimization (AEO) Structuring pages so AI assistants and AI search features can read, quote and cite them. Also called generative engine optimization (GEO). In practice: facts in plain text rather than images or PDFs, a direct answer near the top of each page, and the same information about the practice everywhere it appears online. See [AI visibility](https://fillthelobby.com/services/ai-visibility). ### Cost per click (CPC) What an ad platform charges each time someone clicks an ad. CPC = ad spend ÷ clicks It prices attention, not patients. A low cost per click on searches that never book is expensive. ### Cost per lead (CPL) Marketing spend divided by the inquiries it produced: calls, forms and messages. CPL = marketing spend ÷ inquiries Cheap leads that never book make this number look healthy while the schedule stays empty. ### Cost per booked appointment Marketing spend divided by the appointments actually booked from it. Cost per booked appointment = marketing spend ÷ booked appointments The first number in the chain that has touched the calendar, and the one Fill The Lobby reports on. ### Patient acquisition cost (PAC) The full cost of winning one new patient who attends a first visit. PAC = (ad spend + agency fees + software + staff time on acquisition) ÷ new patients seen Also called cost per acquisition (CPA), or customer acquisition cost (CAC) when the term is borrowed from software. Work yours out with the [patient acquisition cost calculator](https://fillthelobby.com/patient-acquisition-cost-calculator). ## Between the click and the calendar. ### Speed to lead The time between an inquiry arriving and a person responding to it. In a practice it's usually decided by who answers the phone during a session and what happens to a web form at 9pm. See our [speed to lead guide](https://fillthelobby.com/blog/speed-to-lead) and [patient follow-up](https://fillthelobby.com/services/patient-follow-up). ### Missed call text back An automatic text sent to someone whose call went unanswered, offering a way to book or a callback. It gives the caller a next step instead of voicemail. It isn't the same as answering the call. See our [missed call text back guide](https://fillthelobby.com/blog/missed-call-text-back) and [missed call recovery](https://fillthelobby.com/services/missed-call-recovery). ### Conversion rate The share of people who take a named next step. Conversion rate = people who took the step ÷ people who could have × 100 Only useful when the step is named: click to inquiry, inquiry to booking, booking to attended. An unnamed conversion rate can mean any of them. ### Lead-to-booking rate The share of inquiries that become a booked appointment. Lead-to-booking rate = booked appointments ÷ inquiries × 100 The clearest single measure of whether follow-up is working. ### Booking page A page built to take an appointment, not just to describe the practice. Fees, availability and a way to book on one screen, working on a phone at 9pm. See [booking pages](https://fillthelobby.com/services/booking-pages). ### Patient intake Everything between “yes, I'd like to book” and the first appointment: forms, consent, payment details and screening. Long or repetitive intake is where warm patients cool. Ask only for what the first visit needs. ### Good faith estimate A written estimate of expected charges that US providers must give uninsured and self-pay patients. Under the No Surprises Act rules at [45 CFR 149.610](https://www.ecfr.gov/current/title-45/subtitle-A/subchapter-B/part-149/subpart-G/section-149.610), it's due when an uninsured or self-pay patient schedules care or asks for one. For a cash-pay practice it belongs in intake. Our [good faith estimate guide](https://fillthelobby.com/blog/good-faith-estimate) covers the rules with a template, and [functional medicine pricing](https://fillthelobby.com/blog/functional-medicine-pricing) covers how it sits next to a price list. ### Superbill An itemized receipt a practice gives a patient who paid out of pocket, with the codes an insurer needs to consider out-of-network reimbursement. It is not a claim and guarantees nothing: the patient submits it under their own plan, and it shares a diagnosis with their insurer. See [what a superbill includes, with a template](https://fillthelobby.com/blog/what-is-a-superbill). ## Keeping patients. ### Patient retention Keeping patients coming back for the care they need, for as long as they need it. In a private-pay practice most retention work is operational: the next visit booked at checkout, reminders that can be acted on, a phone that gets answered. See [patient retention strategies](https://fillthelobby.com/blog/patient-retention-strategies). ### Patient retention rate The share of patients active at the start of a period who are still active at the end of it. Retention rate = (patients at end − new patients during the period) ÷ patients at start × 100 New patients are taken out so that growth can't hide losses. Work it out with the [patient retention calculator](https://fillthelobby.com/patient-retention-calculator). ### Patient churn (attrition) The share of patients who stop coming during a period without finishing their care. Churn rate = 100% − retention rate Not every departure is churn. A patient who completes a course of care and is discharged is a success; count them separately, or the number punishes good care. ### No-show rate The share of booked appointments the patient neither attended nor cancelled in time. No-show rate = missed appointments ÷ booked appointments × 100 Track it by clinician and appointment type. It's usually concentrated, and the concentration tells you where the fix belongs. Our guide to [reducing patient no-shows](https://fillthelobby.com/blog/reduce-patient-no-shows) covers the fixes. ### Late cancellation A cancellation made inside the notice window a practice sets. Usually counted with no-shows. A window only works if it was stated before the first visit and is applied the same way to everyone. ### No-show fee A charge for an appointment missed without adequate notice. Disclose it in writing before the first visit and apply it consistently. Rules can differ for patients covered by insurance or public programs, so check before charging anyone who isn't paying privately. See [a no-show policy that holds](https://fillthelobby.com/blog/reduce-patient-no-shows#policy). ### Rebooking rate The share of visits where the patient leaves with the next appointment already booked. Rebooking rate = visits with the next appointment booked ÷ visits × 100 The highest-yield retention habit in most practices, and one of the easiest to measure. ### Patient recall Contacting patients when a check-up, review or follow-up visit is due under their own care plan. Recall is about the person's own care, which is treated differently from marketing. See reactivation, below. ### Patient reactivation Contacting lapsed patients or old inquiries with a genuine reason to return. Using protected health information for marketing generally needs the patient's written authorization under [45 CFR 164.508](https://www.law.cornell.edu/cfr/text/45/164.508); communications about the person's own treatment are treated differently under the [definition of marketing](https://www.ecfr.gov/current/title-45/subtitle-A/subchapter-C/part-164/subpart-E/section-164.501). Agree the line with your compliance adviser. See [patient reactivation](https://fillthelobby.com/services/patient-reactivation). ### Patient leakage In health systems, patients referred to providers outside the network. In a private practice the more useful meaning is every point where someone who wanted to book, or rebook, was lost: the unanswered call, the slow reply, the reminder that never went. We count [seven of them](https://fillthelobby.com/patient-acquisition-agency#leaks). ### Patient engagement The contact that keeps a patient connected to their care between visits. Reminders, instructions, answered messages. Software vendors use the same phrase for their platforms; the platform is the tool, and engagement is whether anyone uses it. See [patient engagement strategies](https://fillthelobby.com/blog/patient-engagement-strategies). ### Patient journey The steps from noticing a need to becoming a returning patient. Roughly: search, compare, inquire, book, attend, return, recommend. Each step is a place to lose someone, which is why we map it before changing anything. See [patient journey mapping](https://fillthelobby.com/blog/patient-journey-mapping). ## The economics. ### Patient lifetime value (LTV) The revenue a practice can expect from one patient over the whole relationship. LTV = average revenue per visit × visits per year × years as a patient Multiply by your margin for a profit version. Calculate it with the [acquisition cost and lifetime value calculator](https://fillthelobby.com/patient-acquisition-cost-calculator). ### LTV to PAC ratio Patient lifetime value divided by patient acquisition cost. LTV:PAC = patient lifetime value ÷ patient acquisition cost How many times over a new patient repays what it cost to win them. Below 1, each new patient costs more to win than they will bring in. ### Payback period How many visits it takes for a new patient's revenue to cover what it cost to acquire them. Visits to payback = patient acquisition cost ÷ average revenue per visit A short payback matters most in specialties where many patients come only a few times. ### Cash-pay practice A practice where patients pay directly rather than through insurance; also called private-pay or self-pay. Common in therapy, psychiatry, concierge and direct primary care, functional medicine, ketamine care and weight-loss programs. Patients weigh price and fit before booking, so pages that state fees plainly carry more of the decision. ## The rules. ### Business associate agreement (BAA) A contract a practice signs with a vendor that will handle protected health information on its behalf. A business associate is defined at [45 CFR 160.103](https://www.law.cornell.edu/cfr/text/45/160.103). Sign the agreement before any patient data moves. Most marketing work shouldn't need patient data at all. ### Protected health information (PHI) Health information that identifies a person and is held by a practice or its business associates. Also defined at [45 CFR 160.103](https://www.law.cornell.edu/cfr/text/45/160.103). It never belongs in an ad platform, and patient lists shouldn't be used for ad targeting. ### Patient testimonial A patient's own words used in a practice's advertising. Professional codes limit them: the [APA Ethics Code](https://www.apa.org/ethics/code/ethics-code-2017.pdf), for one, says psychologists don't solicit testimonials from current therapy clients. A review a patient chooses to leave on Google is a different thing; our guide to [Google reviews for doctors](https://fillthelobby.com/blog/google-reviews-for-doctors) covers asking for one. ## Sources - [eCFR — 45 CFR 149.610, Requirements for provision of good faith estimates of expected charges for uninsured (or self-pay) individuals](https://www.ecfr.gov/current/title-45/subtitle-A/subchapter-B/part-149/subpart-G/section-149.610), checked 15 September 2026 - [Cornell LII — 45 CFR 164.508, Uses and disclosures for which an authorization is required](https://www.law.cornell.edu/cfr/text/45/164.508), checked 22 September 2026 - [eCFR — 45 CFR 164.501, Definitions](https://www.ecfr.gov/current/title-45/subtitle-A/subchapter-C/part-164/subpart-E/section-164.501), checked 22 September 2026 - [Cornell LII — 45 CFR 160.103, Definitions](https://www.law.cornell.edu/cfr/text/45/160.103), checked 18 September 2026 - [American Psychological Association — Ethical Principles of Psychologists and Code of Conduct](https://www.apa.org/ethics/code/ethics-code-2017.pdf), checked 18 September 2026 ## Put the formulas to work. Two free calculators that run in your browser, and the page that explains how we use all of this. ## Want these numbers for your practice? ## Related pages - [patient acquisition strategies](https://fillthelobby.com/blog/patient-acquisition-strategies) - [here is what that involves](https://fillthelobby.com/patient-acquisition-agency) - [healthcare SEO](https://fillthelobby.com/services/local-seo) - [AI visibility](https://fillthelobby.com/services/ai-visibility) - [patient acquisition cost calculator](https://fillthelobby.com/patient-acquisition-cost-calculator) - [speed to lead guide](https://fillthelobby.com/blog/speed-to-lead) - [patient follow-up](https://fillthelobby.com/services/patient-follow-up) - [missed call text back guide](https://fillthelobby.com/blog/missed-call-text-back) - [missed call recovery](https://fillthelobby.com/services/missed-call-recovery) - [booking pages](https://fillthelobby.com/services/booking-pages) - [good faith estimate guide](https://fillthelobby.com/blog/good-faith-estimate) - [functional medicine pricing](https://fillthelobby.com/blog/functional-medicine-pricing)