First 100 days post-acquisition for a multi-site healthcare group.

01 Days 1–7: signal, not action

The first week is about signal. The doctors and senior clinical staff are watching. So are the front-desk and billing teams. The signals that actually carry weight in this window are small and concrete: pay runs on time, the new owner is on-site at every location, the existing supplier and lab relationships continue uninterrupted, the same phone numbers ring through to the same staff, and the answer to every "what happens to X" question is "X continues until we have studied it together." The Mybcat playbook calls this "back office first, patient-facing last" and frames it as the single most important sequencing decision in the first thirty days. We have not seen a multi-site healthcare integration succeed when this rule is broken.

Buyers who use week one to push system changes — PMS or EHR migration, new compensation, brand transition, centralised scheduling — burn the integration before the work starts. The seller-era discontent that always exists in these businesses now has a target. Auxo Capital Advisors' two-stage AEC integration framework translates directly to healthcare: stage one is read-only data mirrors, parallel runs, and help-desk support; stage two is a controlled weekend cutover with pre-validated golden transactions and an explicit rollback path. Stage two does not happen in week one. It happens in month four or five at the earliest.

The actions that do belong in week one are different from the ones buyers reach for instinctively. They are: a day-one town hall with the clinical and operational leaders that names the integration philosophy and explicitly confirms that compensation, schedules, and clinical autonomy are unchanged for the protective window. A day-one patient communication that confirms the same provider, same location, same insurance acceptance. A read-only data feed from the seller's PMS or EHR and finance systems into a central BI environment so the integration team can see what is happening without touching anything. Daily site huddles for the first two weeks with a named escalation path. Provider 1:1 meetings begun in week one and completed by day fourteen. The Kaizen post-M&A guidance frames the first three months around "ensuring operational continuity" and "managing integration risks" before any synergy capture — that ordering is the entire game in healthcare.

02 Days 8–30: cash, comp, concentration

The first three weeks of operating-finance work, in this order. Cash: rebuild the 13-week forecast under the new ownership economics — new debt service, new corporate G&A, new comp scenarios, integration-cost outflows — and own it from a named seat. Comp: confirm doctor compensation runs cleanly under the as-is model for at least 90 days, even if the harmonised model is targeted for month four or five. Concentration: identify the top three payer, supplier, and referral concentrations and run sensitivity on each. None of these are integration projects. They are protective work — the finance equivalent of stabilising the patient before treatment, in language a clinical reader will recognise.

The 13-week cash forecast is the single most important artefact of the first thirty days and is also the one most often deferred. The seller's historical cash position was modelled against the seller's ownership economics — owner distributions, family payroll, the embedded sale-leaseback that often shows up in these deals. The new ownership economics include senior debt service, an MSO management fee, integration consulting and conversion costs, and any deferred consideration tied to working-capital true-ups. We have seen post-close cash gaps emerge inside the first sixty days on deals where the buyer thought the seller's reporting was sufficient. Midwest CPA's 100-day plan puts cash-flow management as Step 1 explicitly — "expecting revenue dips, monitoring burn, and controlling discretionary spend" — and it is the right frame.

The comp confirmation is the trust artefact of the first thirty days. Sophisticated PE-backed platforms enter the period with a "no surprises" rule communicated pre-close — typically "no base salary cuts in year one, your variable-comp formula is locked for at least 12 months" — and then the first thirty days are spent inventorying contracts (term lengths, restrictive covenants, current production or collections percentage, stipends, call pay, benefits) and baselining production at the provider level. No structural change. No definition tightening. No payroll-cadence change. HumanR's post-acquisition attrition research is direct about this: if first-six-month attrition runs above 20%, "you're losing the asset you bought." For provider attrition specifically, the platform-grade benchmark is below 5% at month six and below 10% at month twelve. The work in days 8-30 is the work that holds that line.

The concentration sensitivity is the protective work the seller almost certainly did not maintain. Most multi-site healthcare sellers are running with two or three payer relationships, one or two lab or supply relationships, and one to three referral-source relationships that together drive 40-60% of contribution. The 30-day exercise is to name them, to confirm the contract terms are stable through at least month twelve, and to model what happens if any single relationship is reduced by 30%. The output is a one-page concentration map that the integration team revisits monthly for the rest of the year. It is rarely interesting until it is suddenly the only thing that matters.

03 Days 31–60: rebuild the operating P&L at the site level

By day 31 the seller's consolidated P&L should be rebuilt at the site level, with the operating cut that the location leaders can actually read. Most acquisitions inherit a P&L that the seller's accountant could read and the operator could not — gross revenue, total expenses, owner add-backs, EBITDA, done. The fractional or interim CFO's job in days 31-60 is to make every location individually visible — net revenue by line, direct clinical costs to contribution after labour, occupancy to contribution after occupancy, site EBITDA pre-corporate allocations — and to circulate it monthly inside ten business days of close. Greenberg Traurig's 2026 mid-market M&A reporting summary names the expectation directly: PE-backed healthcare boards now require site-level EBITDA within five business days of month-end, and lenders are not far behind.

The six-line operating cut that we use

The structure we land on in every multi-site healthcare integration: line one, net revenue by major service line — preventive vs restorative vs specialty in dental, GP vs specialty vs hospital in vet, medical derm vs cosmetic vs MOHS in derm. Line two, direct clinical costs — provider compensation gross of any owner add-backs, clinical staff wages, benefits and payroll taxes, variable clinical supplies and lab COGS. Line three is contribution after labour. Line four, occupancy and facility — rent including any sale-leaseback escalations, CAM, utilities, maintenance. Line five is contribution after occupancy, which is the cleanest single number for benchmarking site performance because it isolates everything inside the site's control. Line six is site EBITDA pre-corporate allocations, with the management-services fee and central RCM/IT/finance allocations broken out separately for the lender-and-board view only. Site leaders do not get the allocated view by default — it is the wrong incentive for the wrong audience.

On top of the operating P&L sits a vertical-specific KPI layer. For DSOs: production per chair, production per provider, hygiene reappointment rate, treatment acceptance rate, collections lag, EBITDA per chair. For veterinary platforms: average transaction value, client retention rate, COGS percentage, inventory turnover, appointment-book utilisation. For dermatology: visits per provider, procedure mix (medical vs cosmetic vs MOHS), appointment lag, denial rate, days in AR. The same shape across every vertical: a tight cross-platform spine plus four to six vertical-specific metrics that the local leadership can move. Bridgepoint's 100-day KPI framework puts seven categories on the dashboard — workforce, customer, operational, financial, technology, cultural, regulatory — and in healthcare we add patient-retention and quality metrics into the customer slot per Bain's post-merger guidance on "keeping customers first." That last point matters more in healthcare than in any other operating sector: the asset is the relationship, and the relationship lives between the patient and the provider, not between the patient and the brand.

04 Days 61–90: harmonisation, with consent

Days 61–90 are when harmonisation work — comp model design, billing-system standardisation, supply-chain consolidation, brand transition, selective patient-facing improvements — can begin. The political precondition is that the clinical and operational teams have, by this point, lived under the new ownership for two months and seen the protective work done first. Harmonisation that lands in this window lands. Harmonisation that lands in week two creates a discontent the integration carries for a year. The Mybcat sequencing is explicit on this: phase three (selective patient-facing changes) is the day 61-90 window, and visible service improvements are introduced before patients or providers are asked to tolerate friction.

Comp harmonisation design — not go-live

The day 61-90 comp work is design, not go-live. The draft harmonisation framework gets built: which cohorts move to which model (associates to platform-standard production or RVU bands, founders staying on legacy economics through the earn-out period, specialists handled individually), what the platform-standard target percentages or RVU rates are, what the standardised definitions of "adjusted production" or "net collections" cover. Then individual-impact modelling: for each provider, the historic comp under the as-is model is compared against the proposed new model on the trailing 12 months of production. Winners, neutral, and at-risk are identified. The at-risk cohort gets grandfathered or floored for 6-24 months. The 1:1 conversations with the top 20% of producers happen in this window, with their personal pro-forma in hand. The day 60 milestone is design complete. The day 90 milestone is go-live for new hires and acquired associates only — founders and high producers stay on their legacy economics through the earn-out, typically two to five years, and migrate later. Tend's 2024 public move to 40% of adjusted production for dental associates and the 28-35% range that Drill Down Solution and Doctors Choice cite as the platform-standard band give the calibration anchor.

The PMS / EHR conversation

Practice management system migration is almost always the loudest harmonisation project and almost always the wrong first one. The cost of the migration is rarely the cost of the software. It is the cost of three months of half-trained front-desk and clinical teams under a new system while production is supposed to be holding. The Siotek 2026 guidance on Dentrix Ascend conversions puts the realistic single-site impact at 10-20% scheduled-production reduction in the first one to two weeks, 15-25% realized revenue below baseline in the same window, and a return to 90-95% of baseline by week three or four — assuming a well-planned migration with a 2-4 week parallel run, weekend cutover, and full-day front-desk training plus half-day clinical training. Imaging migration is the most fragile sub-track and we keep it on legacy for an additional defined period in almost every deal. For veterinary, ezyVet's own Cornerstone-conversion documentation describes a similar two-to-three week parallel run.

The portfolio implication: stagger PMS go-lives so no more than 20-25% of platform production is in a "go-live month" at any time, and underwrite 2-5% EBITDA drag in the heaviest migration quarter. We sequence PMS into month four or five at the earliest in most deals, with the conversion-quarter EBITDA drag explicitly built into the lender covenant negotiations pre-close. Buyers who do not size the conversion-quarter drag end up with a covenant problem on top of an operational one — which is the worst possible time to renegotiate.

05 Days 91–100: the handoff to year-one operating

The last 10 days of the window are a handoff. The integration team — the interim or fractional CFO who has run the protective work, plus whoever has owned the day-1 communication and provider 1:1 cadence — hands the operating finance function to its permanent owner, and the harmonisation work that has begun is transferred into the year-one operating plan with a written calendar. The 100-day window does not end the integration. It ends the protective period and starts the operating one. Months three to twelve are when the PMS conversions actually happen, when the comp model goes live for the founders coming off their guarantees, when the brand transition and patient portal roll out, when the procurement consolidation lands. None of that work survives if the protective window was botched.

The handoff check is short and concrete — five questions, in writing, with names attached. If any of them get a soft answer, the protective period extends and the handoff slips.

1. Does the 13-week forecast under new ownership exist, is it being refreshed weekly, and is it owned by a named seat (the permanent CFO or controller, not the integration team)?
2. Are the as-is doctor and clinical compensation models running cleanly through month three with zero payroll lag and zero unexplained variance from the pre-close run rate?
3. Has the site-level operating P&L been rebuilt on the six-line cut, been circulated to every location lead at least twice, and is it landing inside ten business days of month-end?
4. Has the PMS / billing / brand harmonisation calendar been pushed to month four-plus, with the consent of the clinical leaders and the conversion-quarter EBITDA drag explicitly built into the lender covenant model?
5. Has the concentration sensitivity (top three payers, suppliers, referral sources) been documented, dated, and assigned to a monthly review?

The companion reads for the operating phase that begins on day 101 are the DSO Day 1-to-100 integration playbook for the dental-specific operational rhythm, the 100-day post-close integration calendar for the cross-sector calendar template, and the buy-side QoE for multi-site healthcare piece for the diligence findings that should have driven the integration plan in the first place. The Q2 2026 multi-site healthcare M&A multiples piece sets the valuation context that frames how much value protection the first 100 days are actually worth — at the 9-12x EBITDA range we see for healthy platforms, a 100bp EBITDA preservation is worth nine to twelve times that at exit. The provider-productivity-DSO-single-metric piece names the single operating metric the year-one plan should converge on once the protective period closes.

06 What actually kills value in the first 100 days

Across the nine multi-site healthcare integrations we have advised on, five failure patterns recur and each maps cleanly to a sequencing error in days one through forty. None of them are about price.

1. 01
   Patient-facing changes pushed too early. PMS or EHR migration, call-centre routing changes, centralised scheduling, brand or signage transition inside the first thirty days. The result is appointment leakage, online-review damage, and front-desk turnover that compounds. Mybcat is explicit: parallel systems and rollback for all patient-facing tech changes; no logo or signage changes until the patient-facing consent process is complete. We have not seen a buyer recover from a first-month PMS push without a measurable Q1 EBITDA hit.
2. 02
   Comp model changes announced before trust. Any visible change to comp structure, payroll cadence, or definitional scope in days one through ninety is read by the clinical team as "you bought me to cut my pay." The downstream cost is provider attrition concentrated in the top 20% of producers, which is the cohort the deal was underwritten against. HumanR's research surfaces sentiment dips approximately four weeks before the actual resignation, which is why the day 14 provider 1:1s and the monthly pulse survey matter as the early-warning system.
3. 03
   Cash discipline deferred while integration consultants run the meeting. The 13-week forecast does not exist by day seven; the protective integration meetings have soaked up the new CFO's time; the seller-era cash discipline has lapsed because everyone is in transition mode. Midwest CPA's plan puts cash-flow mastery as Step 1 for a reason — revenue dips early in the integration are normal, and the buyers who survive them are the ones who saw them in the forecast two weeks before they hit.
4. 04
   Concentration risk not surfaced. The top three payers, suppliers, and referral sources were named in the QoE and then forgotten by day thirty. The contract-expiry calendar is not on anyone's desk. A single relationship rolls off in month four or five and the integration team is surprised. The 30-day concentration sensitivity exists precisely to prevent this and it takes a finance analyst three days to build.
5. 05
   No protective-to-operating handoff. The integration team does not hand off to a named permanent operator; the harmonisation calendar is not written down; the year-one plan inherits everything informally and immediately drops things. By month six the cash forecast is stale, the site P&L has stopped being circulated, the provider 1:1 cadence has lapsed, and the integration is "done" in the same sense that a half-finished renovation is "done." The day 91-100 handoff is the work that prevents this and most integrations skip it.

07 What this means for buyers, sellers, and the operators between them

Three implications come out of this for the people who actually have to do the work in the first 100 days.

For buyers underwriting the deal

Build the conversion-quarter EBITDA drag into the lender covenant model pre-close. Underwrite 2-5% EBITDA drag in the heaviest PMS-migration quarter, two to four weeks of 10-20% production reduction at any site going live, and a 30-day AR lag through the cutover month. If the covenant package does not flex for that, the integration plan has to flex around the covenant — which means either accepting a higher attrition risk by pushing PMS migration into the protective window, or accepting a slower harmonisation timeline than the IC plan assumed. Both are worse than negotiating the covenant before close. PwC's 2026 health-services outlook calls out the buyers who underwrite this discipline as the cohort that wins the next cycle.

For sellers approaching a process

The first 100 days post-close are the most expensive period in the seller's life if the comp model, the PMS, and the patient experience are not stable going in. Buyers will discount for the integration risk in the price; lenders will discount in the covenant package. Stabilising the comp model definitions, modernising the PMS to a defensible standard, and documenting the clinical-quality metrics inside the 6-12 months before opening a process is the cheapest valuation work most sellers never do. The buy-side QoE for multi-site healthcare companion piece names the diligence findings that drive most of the price adjustment; the day 1-to-100 work is the same list run backwards.

For the operators between them

The fractional or interim CFO who runs the first 100 days is doing protective work, not transformation work, and the engagement scope should reflect that. Cash forecast ownership, the site-level P&L rebuild, the comp-confirmation cycle, the concentration sensitivity, the day-91 handoff — that is the brief. The harmonisation work that follows is a separate engagement, with separate measurement, owned by the permanent operator who has lived inside the integration for ninety days by the time it begins. Conflating the two is the most common integration sequencing error we see in healthcare deals and the one that costs the buyer the most over the first year. The integration finance work is finite, dated, and handed over. The operating work is permanent.