Key Takeaways
TruCare is our first pick among regional independents. TruCare OS brings intake, medical billing automation, and credentialing into one record, and its team handles HIPAA, filing deadlines, and coding rules that surround every claim.
Your billing company is a business associate. Federal law requires a signed Business Associate Agreement before it touches patient records, and a breach must be reported within 60 days of discovery.
Deadlines differ by payer. Medicare expects claims within 12 months of the date of service, while Medicaid and commercial plans set shorter windows that vary by state and contract.
Regional knowledge is the independent’s edge. Among regional medical billing companies in the USA, a firm rooted in one region knows its state Medicaid program and its local payers, which a national chain often handles through a generic playbook.
Published pricing is rare. TruCare lists rates from 2.49% of collections and Docs Medical Billing starts at 2.99%. The rest quote on request.
1. TruCare
TruCare
Bermuda Dunes, CA
5.0 / 5 · Our rating
Best for
Practices that want an independent regional partner with a published rate
Company Overview
TruCare's medical billing keeps every claim on one patient record that four tools share:
TruIntake covers scheduling, intake, and eligibility.
TruRev runs billing from charge entry to cash posting.
TruCred handles credentialing and payer enrollment.
TruIntel reports on claims, denials, and A/R as they move.
It is an independent company based in Bermuda Dunes, California, serving practices from its Coachella Valley office, with certified billers working the claims the software flags. TruCare also takes care of the compliance work around each claim, including HIPAA safeguards and Business Associate Agreements, OIG exclusion screening, Medicare and payer filing deadlines, and current coding edits. It works in the EHR a practice already uses, so clinicians keep their own workflow.
Free, with no obligation
Pros and Cons
Pros
- Intake, eligibility, billing, and credentialing share one record
- Handles HIPAA, exclusion screening, and filing-deadline compliance as part of the service
- Credentialing handled in-house, useful when adding payers or clinicians
- Publishes its pricing, from 2.49% of collections
Cons
- Based in Southern California, so confirm coverage of your state’s Medicaid program
- Founded in 2022, a shorter record than longer-established firms
- Contract terms come on request rather than posted
Pricing
Published, from 2.49% of collections. Industry guides put medical billing nearer 4% to 8%, so ask what each quote covers.
Best For
Small and mid-size practices that want one partner for billing and credentialing, with compliance handled alongside.
Key Features / USPs
Automated intake and eligibilityClaim submission and follow-upPayer credentialing and enrollmentDenial managementTruIntel reporting
Our Verdict
One platform and a rate you can read before you call. It suits a practice that wants the same team to credential its providers, file its claims, and keep the compliance paperwork current.
Reviews from Reddit, Google, and Trustpilot
Google“Our private practice has peace of mind knowing billing is handled correctly.”
Trustpilot“No Trustpilot reviews yet.”
Reddit“No Reddit reviews yet.”
Average Review Score and Summary of Reviews
5.0 / 5
2. Docs Medical Billing
Docs Medical Billing
Madera, CA
5.0 / 5 · Our rating
Best for
Practices that want a published rate and a free review of their claims
Company Overview
Docs Medical Billing is a California revenue cycle company in Madera, in the Central Valley, that publishes a starting rate of 2.99% of collections. It offers a no-cost billing analysis to find revenue leaks before any commitment, then works through eligibility, prior authorization, coding, claims, and A/R follow-up. It pairs AI claim scrubbing with human verification, reports a clean claim rate of up to 98%, and says more than 200 providers rely on it. Credentialing includes CAQH and PECOS enrollment, and the company is accredited by the Better Business Bureau. Ask how it handles Business Associate Agreements, where patient data is stored, and which EHRs the team has worked in.
Free, with no obligation
Pros and Cons
Pros
- Published starting rate of 2.99% of collections
- No-cost billing analysis before you commit
- CAQH and PECOS credentialing and enrollment support
- BBB accredited, with an A rating
Cons
- Reported clean claim rates come from the company
- Prices beyond the starting rate depend on scope
- Compliance practices such as Business Associate Agreements are not detailed publicly
Pricing
Published, starting at 2.99% of collections. Confirm what the rate covers.
Best For
Cost-conscious practices that want a clear starting number and a free look at their own claims.
Key Features / USPs
Revenue cycle managementNo-cost billing analysisPrior authorizationA/R managementCAQH and PECOS credentialing
Our Verdict
Clear pricing and a low-risk way to test the work. Ask for two references from your region and for the written compliance terms before you sign.
Reviews from Reddit, Google, and Trustpilot
Google“Docs Medical Billing LLC has been wonderful to work with. They are responsive and attentive. I have never experienced the attention to detail that they provide. If you are looking for a billing company, I highly recommend Docs Medical Billing for your practice.”
Trustpilot“No Trustpilot reviews yet.”
Reddit“No Reddit reviews yet.”
Average Review Score and Summary of Reviews
5.0 / 5
3. Advanced Medical Billing and Collections
Advanced Medical Billing and Collections
East Brunswick, NJ
5.0 / 5 · Our rating
Best for
New Jersey practices that want a coder-led team and optional remote staffing
Company Overview
Advanced Medical Billing and Collections, known as AMBNJ, is a company in East Brunswick, New Jersey, founded in 2011 by Chinal Patel, a Certified Professional Coder, a credential from AAPC. It handles claim submission, clinical coding, credentialing and enrollment, denial management, and A/R follow-up, and it offers remote staffing for practices that want dedicated billing staff. It reports a clean claim rate of about 98%, a figure that comes from the company, and credits it to certified coders reviewing claims before they go out. Its Google reviews, 5.0 from 19, come from practices that describe regular reporting, monthly meetings, and a team that follows up on denials and authorizations, including a client of about ten years. If any work is done outside the United States, ask where patient data is stored and who can access it.
Free, with no obligation
Pros and Cons
Pros
- Founded and led by a certified coder
- Coding, credentialing, billing, and remote staffing under one roof
- Regular reporting and monthly meetings, according to clients
- Long-term clients, including one of about ten years
Cons
- Reported claim rates come from the company
- Prices are not published
- EHR integrations are not listed
Pricing
Not published. AMBNJ quotes on request.
Best For
New Jersey practices that want certified-coder review and the option of dedicated remote staff.
Key Features / USPs
Clinical codingClaim submissionCredentialing and enrollmentDenial managementRemote staffing
Our Verdict
A founder-led firm with a coding-first approach and long-term clients. Ask for two New Jersey references, a sample monthly report, and where patient data is handled.
Reviews from Reddit, Google, and Trustpilot
Google“Outstanding professionalism and top-notch service! Advanced Medical Billing and Collections company is a testament to efficiency, reliability, and expertise in their field. Highly recommended for their exceptional quality service.”
Trustpilot“No Trustpilot reviews yet.”
Reddit“No Reddit reviews yet.”
Average Review Score and Summary of Reviews
5.0 / 5
4. VB Billing & Credentialing Services
VB Billing & Credentialing Services
Manhattan, NY
4.9 / 5 · Our rating
Best for
Practices that want an owner-led Manhattan team for billing and credentialing
Company Overview
VB Billing & Credentialing Services is a locally owned medical billing company in Manhattan that handles billing and insurance credentialing for small offices. Its Google reviews, 4.9 from nearly 100, describe a hands-on owner who credentialed offices with major insurers, acts as a one-stop shop for the office, and works with the care of someone whose name is on the door. Public detail about its services, fees, and EHR support is limited, so ask for the written scope, the percentage, and how it handles Business Associate Agreements and payment accounts before you sign. Ask for two New York references and a sample monthly report.
Free, with no obligation
Pros and Cons
Pros
- Owner-led, with long-term clients who describe personal attention
- Billing and credentialing from one team
- One of the largest review bases among the independents here
- Manhattan-based, with direct access to the people doing the work
Cons
- Limited public detail on services and pricing
- Prices are not published
- EHR integrations are not listed
Pricing
Not published. VB Billing & Credentialing Services quotes on request.
Best For
Small New York offices that want an owner they can call directly.
Key Features / USPs
Medical billingInsurance credentialingOffice supportClaims follow-up
Our Verdict
A personal, highly rated option for small offices. Get the scope and compliance terms in writing, since little of it is posted online.
Reviews from Reddit, Google, and Trustpilot
Google“We’ve had the pleasure of working with Valerie at VB Billing, and the experience has been nothing short of exceptional. Valerie is professional, knowledgeable, and truly dedicated to her clients. Her attention to detail and commitment to accuracy in medical billing makes her stand out in the industry.”
Trustpilot“No Trustpilot reviews yet.”
Reddit“No Reddit reviews yet.”
Average Review Score and Summary of Reviews
4.9 / 5
5. A3 Medical Billing
A3 Medical Billing
New Jersey and New York
5.0 / 5 · Our rating
Best for
Startups and small practices that want billing, credentialing, and MIPS support together
Company Overview
A3 Medical Billing Services, LLC provides medical billing and coding, revenue cycle management, A/R management, provider credentialing, prior authorization, eligibility verification, denial management, and lab billing, and it adds MIPS and MACRA support for practices that must meet CMS quality reporting rules. It serves practices in New Jersey and New York, with a Fargo, North Dakota office on its Google listing and location pages for other states. Its Google reviews, 5.0 from 16, come from agencies and clinics that praise credentialing and billing, and one reviewer was refunded when credentialing could not move forward. Several reviewers also mention its website work, so billing is one service among several, and it is worth confirming how much of its work is billing for practices like yours.
Free, with no obligation
Pros and Cons
Pros
- Billing, credentialing, prior authorization, and eligibility checks together
- MIPS and MACRA support for CMS quality reporting
- Refunded a client when credentialing could not proceed
- Responsive communication, according to reviewers
Cons
- Billing is one of several services it offers
- Prices are not published
- EHR integrations are not listed
Pricing
Not published. A3 Medical Billing quotes on request.
Best For
New agencies and small practices that want credentialing and billing started together, with quality reporting support.
Key Features / USPs
Billing and codingProvider credentialingPrior authorizationEligibility verificationMIPS and MACRA support
Our Verdict
A responsive option for practices launching or reorganizing. Ask for two references from your state and a written scope that separates billing from its other services.
Reviews from Reddit, Google, and Trustpilot
Google“We are extremely pleased with the billing services provided. The team is knowledgeable, responsive, and efficient. Claims are processed quickly, denials are handled proactively, and communication is excellent. Their expertise in primary care and MAT billing has been especially valuable to our practice. Highly recommend.”
Trustpilot“No Trustpilot reviews yet.”
Reddit“No Reddit reviews yet.”
Average Review Score and Summary of Reviews
5.0 / 5
Regional Independent Medical Billing Companies: Side by Side
Five companies, five columns. "Not listed" means we could not find the detail publicly.
| Company | Pricing model | Core services | Tech / EHR integrations | Best for |
|---|---|---|---|---|
| TruCare (Southern California) | % of collections, from 2.49% | Billing, credentialing, and compliance handling | Works in your existing EHR | One record and a published rate |
| Docs Medical Billing (Central California) | % of collections, from 2.99% | Billing, RCM, and credentialing | Epic, athenahealth, NextGen, Tebra, and others | A published rate and a free review |
| Advanced Medical Billing and Collections (New Jersey) | Quote-based | Coding, billing, credentialing, and remote staffing | Not listed | A coder-led New Jersey team |
| VB Billing & Credentialing (Manhattan) | Quote-based | Billing and credentialing | Not listed | An owner-led Manhattan team |
| A3 Medical Billing (New Jersey and New York) | Quote-based | Billing, credentialing, prior authorization, and MIPS support | Not listed | Startups and quality reporting |
Independent vs National Medical Billing Companies
The biggest difference between independent vs national medical billing companies is who answers your call and who makes the decisions. A locally owned medical billing company is usually run by its founder or a small team, while a national chain may be backed by private equity and run through standard playbooks. Neither model is automatically better, so match the model to your practice.
| Question | Independent regional firm | National chain |
|---|---|---|
| Ownership | Owned and run by its founders or operators | Often investor-backed or part of a larger group, including private equity |
| Who you reach | The people doing your billing | A rotating account team |
| Payer knowledge | Deep in one state’s Medicaid program and local payers | Broad, built on standard processes across states |
| Pricing | Quoted case by case, with a few publishing rates | Tiered contracts, often with minimums |
| Technology | Usually works in your EHR | May push its own platform |
| Compliance proof | Varies, so ask for it in writing | Often holds formal attestations such as SOC 2 or HITRUST |
| Main risk | A small team can strain during growth or turnover | Contract terms can be harder to change |
For a small practice, the best independent medical billing company is the one that can show named references in your state, a signed Business Associate Agreement, and written compliance terms. If you need coverage in many states or an enterprise security attestation, a national firm may fit better. Ask any company, independent or national, to confirm its ownership in writing and whether it belongs to an industry body such as the Healthcare Business Management Association (HBMA).
The US Compliance Rulebook for Medical Billing
Medical billing compliance in the US stacks federal rules on top of state and payer rules. This section follows a claim through three stages, and you can use it to test any regional medical billing company, whether independent or national.
Your biller is a business associate.
Under HIPAA and the HITECH Act, a billing company that handles patient data is a business associate, so it needs a signed Business Associate Agreement, and the HIPAA Privacy and Security Rules apply to it directly.Breaches have a 60-day clock.
Under the Breach Notification Rule, affected patients must be told without unreasonable delay and no later than 60 days after a breach is discovered.The Security Rule update is still a proposal.
HHS proposed a major Security Rule update in January 2025. As of late 2026, it is not final, and the federal regulatory agenda now targets final action around July 2027, so the current rule remains in force.Excluded people cannot touch your claims.
Federal programs will not pay for services involving anyone on the OIG List of Excluded Individuals/Entities, and hiring or contracting with an excluded person can bring civil penalties, so billers should check the list monthly.Enrollment comes first.
Medicare enrollment through PECOS, CAQH for many commercial plans, and each state’s Medicaid portal must be complete and current before claims are filed.Prior authorization is getting faster.
CMS’s interoperability and prior authorization rule requires many Medicare Advantage, Medicaid, and exchange plans to answer authorization requests within set timeframes starting in 2026, so a biller should track each request instead of waiting for a call.- On the claim
Codes must match the record.
Claims use CPT and HCPCS codes for services and ICD-10-CM for diagnoses, updated on fixed schedules each year, and the note must support both the code and the medical necessity. - On the claim
NCCI edits block bundled codes.
The CMS National Correct Coding Initiative edits stop certain code pairs from being billed together, and many commercial plans apply similar logic. - On the claim
Medicare allows 12 months.
Medicare claims must be filed within 12 months of the date of service under 42 CFR 424.44. Medicaid and commercial deadlines vary by state and contract, and many are much shorter. - On the claim
Medicare pays the provider, not the biller.
Even when a billing company is paid a percentage, Medicare payments must go to an account the provider controls, so a biller should never ask you to route payments to its own account. - On the claim
Claim formats are standardized.
Professional claims use the CMS-1500 or the 837P electronic format, and facility claims use the UB-04 or the 837I. Most claims travel through a clearinghouse, and payers return an electronic remittance advice (ERA) and pay by electronic funds transfer (EFT), so a biller should reconcile every deposit against its remittance. - After the claim
Overpayments must be returned.
Medicare and Medicaid require providers to report and return overpayments within 60 days of identifying them, so a biller needs a process for finding and reporting credits. - After the claim
The False Claims Act reaches billing errors.
Knowingly submitting, or failing to correct, a false claim can bring treble damages and per-claim penalties under the False Claims Act, and the Anti-Kickback Statute bars payments in exchange for referrals. - After the claim
A compliance program is expected.
OIG’s General Compliance Program Guidance describes the seven elements of an effective program and explains how small firms can scale it. - After the claim
Surprise-bill rules protect patients.
The No Surprises Act requires good faith estimates for uninsured and self-pay patients and sets protections for certain out-of-network bills. - After the claim
Collections have their own rules.
A billing company that pursues past-due patient balances may fall under the Fair Debt Collection Practices Act and state collection laws. - The state layer
Regions and states add their own rules.
Each region has its own Medicare Administrative Contractor, such as Noridian in California, Novitas in New Jersey, and National Government Services in New York, each with its own portal and local coverage policies. State Medicaid programs, such as Medi-Cal, New Jersey Medicaid, and New York’s eMedNY, set their own filing limits, prior authorization requirements, and enrollment portals, and states layer privacy laws on top of HIPAA. This is where a regional firm earns its keep.
Where Medical Claims Break
| Where it breaks | What it costs | What a good partner does |
|---|---|---|
| Claim filed after the payer’s deadline | Denial with little route back | Tracks every payer’s window from the date of service |
| Billing company receives Medicare payments in its own account | Compliance violation | Keeps payments in an account the provider controls |
| Code pair rejected by an NCCI edit | Denial or downcode | Checks edits and modifiers before submission |
| Note does not support the billed code | Denial or recoupment on audit | Audits documentation against the code |
| Overpayment left unreported past 60 days | False Claims Act exposure | Flags credits and reports them promptly |
| Staff member found on the exclusion list | Civil penalties | Screens employees and contractors every month |
| Patient data shared without a Business Associate Agreement | HIPAA violation | Signs the agreement before it sees a record |
| Self-pay patient given no good faith estimate | Payment dispute | Prepares the estimate before service |
| Past-due patient balance sent to collections too early | Complaints and legal risk | Follows collection rules and your written policy |
How to Choose Among Regional Medical Billing Companies
A company’s website will tell you it is compliant. Put the same eight questions to every independent billing company you shortlist, and listen for answers that name a person, a document, and a date.
Ask These Questions
Vague answers promise that the team “takes compliance seriously.” Strong ones are specific. Ask these during your demo to make a more informed decision.
- ExperienceHow many practices like mine, in my state, do you bill for today?
- HIPAAWill you sign a Business Associate Agreement, and where is patient data stored and accessed?
- ScreeningHow often do you check staff and contractors against the OIG exclusion list?
- DeadlinesHow do you track each payer’s filing window from the date of service?
- CodingWho audits claims against NCCI edits and annual code updates before submission?
- PaymentsDo payments go into an account I control, and can I see it directly?
- OverpaymentsHow do you find credits and report overpayments within 60 days?
- Exit TermsWhat happens to my data and open claims if I leave?
Get the answers in writing
Send these 8 questions to every company you shortlist, so you can compare the answers side by side.
Signals to Walk Away From
- A percentage quoted on billed charges instead of collections
- Payments routed to the billing company’s own account
- No willingness to sign a Business Associate Agreement
- Collection rate promises with no client data behind them
- No read-only access to your own claim and payer systems
Build In-House or Outsource?
| Question | In-house team | Outsourced partner |
|---|---|---|
| What you pay for | Salary, benefits, software, training | A share of collections or a flat fee |
| What happens when someone leaves | Claims wait for a replacement | Another biller picks up the queue |
| Compliance workload | You track every rule yourself | Shared, but you remain responsible |
| How you supervise | Daily and direct | Through reports and scheduled calls |
| Where it fits best | Larger practices with a stable team | Small and growing practices, or after turnover |
Compliance Essentials Your Biller Should Already Know
Privacy and security.
HIPAA applies to your billing company directly. It should have a signed Business Associate Agreement, role-based access to records, encrypted systems, and a written breach plan that fits the 60-day notification rule. Larger firms often hold a security attestation such as SOC 2 or HITRUST, and smaller ones should be able to show equivalent safeguards. The 21st Century Cures Act’s information-blocking rules also mean your billing partner must never slow a patient’s request for records.
Coding and documentation.
Certified coders, credentialed through bodies such as AAPC or AHIMA, should check each claim against NCCI edits, annual code updates, and the note that supports it. A billing company that bills what the record does not support exposes you, not just itself.
Payment handling.
Payments from Medicare must reach an account you control, and the same discipline protects you with other payers. Ask to see the account and how deposits are reconciled each month.
Fraud-and-abuse readiness.
The False Claims Act, the Anti-Kickback Statute, and the OIG exclusion list all reach billing work. Your partner should screen its staff, report overpayments on time, and keep a compliance program that follows OIG guidance.
What Does Medical Billing Cost from Regional Independent Firms?
Most medical billing companies charge a share of collections, so their income follows yours. Published guides put medical billing at roughly 4% to 8%, and regional independents tend to land inside that band. Scope moves the number more than the model: whether eligibility, prior authorization, credentialing, patient statements, and compliance screening are included, and what any AI medical billing actually decides.
4% to 8%
of collections is the typical range. TruCare’s published 2.49% and Docs Medical Billing’s 2.99% both fall below it, so ask what each quote covers.
Fixed
Monthly pricing suits steady volume but gets expensive when claims dip. Get the included services in writing.
Separate
Credentialing, remote staffing, and quality reporting support are often priced apart from billing. Ask every company for each number.
Mistakes Practices Make When Hiring a Biller
- 1
Choosing on rate alone.
A low percentage can hide extra fees or thin compliance work. Compare what each quote includes, not just the number. - 2
Letting the biller collect into its own account.
Medicare payments must go to an account you control. Keep that control with every payer. - 3
Skipping the Business Associate Agreement.
A biller that sees patient data without a signed agreement puts you in breach of HIPAA from day one. - 4
Ignoring your state’s Medicaid rules.
Filing limits, prior authorization, and enrollment portals differ by state, so ask how the team learns yours. - 5
Skipping the reference calls.
Two conversations with practices in your region tell you more than any proposal.
How We Ranked These Companies
Every company here is scored against the same six criteria below, weighted as shown, then ranked by weighted total. TruCare tops the list. We list only independent medical billing companies, meaning firms that appear to be independently owned, as far as public records and company sites show, and we exclude software vendors and national chains. Billing and coding depth carries the most weight, which is why a focused specialist can outrank a larger firm with a broader menu. Placement is not for sale, and testimonials published on a company's own website do not count toward its score. A rating drawn mainly from employee or recruitment reviews is shown but not scored.
| Criterion | Weight | What we look at |
|---|---|---|
| Billing and coding depth | 30% | Certified coding, denial management, credentialing, prior authorization, and compliance handling |
| Regional payer knowledge | 20% | State Medicaid experience, local payer relationships, and references in the region |
| Transparency | 15% | Published pricing or a clear quote process, contract terms, data access |
| Technology and EHR fit | 15% | Works inside your EHR, reporting the client can see |
| Verified client feedback | 10% | Google, Trustpilot, and Reddit ratings and written reviews |
| Onboarding and support | 10% | Named contact, written onboarding plan, credentialing timeline |
Data sources
Company websites and service pages, public business records, HHS, OIG, and CMS guidance, and verified public reviews.
Review process
Each profile is drafted from primary sources, checked by a second reviewer, and re-verified at every update.
Conflict of interest disclosure: TruCare publishes this guide and appears on this list. We scored TruCare against the same criteria as every other company, and we accept no payment for placement. Read our editorial policy.
Final Picks: Which One Fits You?
- TruCare if you want an independent regional partner, one record, and a published rate.
- Docs Medical Billing if you want a published starting rate and a free analysis.
- Advanced Medical Billing and Collections if you want a coder-led New Jersey team with remote staffing.
- VB Billing & Credentialing Services if you want an owner-led Manhattan team.
- A3 Medical Billing if you are starting out and want billing, credentialing, and MIPS support together.
Frequently Asked Questions
Regional medical billing companies are firms rooted in one part of the country that know its Medicaid program, its payers, and its practices. A US independent firm is a locally owned medical billing company run by its founders or operators rather than a national chain, so you usually deal with the people doing the work. Ask any company to confirm its ownership in writing.
It depends on your state and specialty. For most small practices, TruCare is our pick for the best independent medical billing company, because intake, billing, and credentialing run on one record with a published rate. Docs Medical Billing is the strongest published-rate alternative, and VB Billing is the owner-led option in Manhattan.
Independent firms are owned and run by their founders, so you deal with the people doing the work and a team that knows its region’s payers. National chains, which are often investor-backed, offer wider coverage and formal security attestations but usually run standard playbooks. The comparison above shows what changes for you.
Most firms charge a share of collections, typically 4% to 8%. TruCare publishes rates from 2.49% and Docs Medical Billing starts at 2.99%. The rest quote on request. Compare what each rate includes, not just the number.
Yes. HIPAA requires a signed agreement before a billing company handles patient information, and the company must follow the Privacy and Security Rules directly.
Medicare generally requires claims within 12 months of the date of service. Medicaid and commercial plans set their own windows, which vary by state and contract, so ask any company how it tracks each payer.
No. Medicare payments must go to an account you control, even when the billing company is paid a percentage of collections. Be wary of any firm that asks you to route payments to its own account.
Not yet. HHS proposed a major update in January 2025, but it is not final, and federal planning documents now point to around July 2027. The current Security Rule still applies.
It lists people and companies barred from federal health programs. Billing companies should check staff and contractors against it monthly, since federal programs will not pay for services involving an excluded person.
An overpayment is money received that you were not owed. Medicare and Medicaid rules require providers to report and return overpayments within 60 days of identifying them, so a biller should have a process for finding credits.
It is not prohibited, but it adds privacy and security questions. Ask where patient data is stored, who can access it, and how the company enforces HIPAA protections for any work done outside the United States.
Many will. Docs Medical Billing lists Epic, athenahealth, NextGen, and Tebra, and TruCare works in the EHR a practice already uses. The rest do not publish theirs, so confirm in writing, including who pays for additional user licenses.