Step 1: apply to be on insurance panel (i.e., be a provider on that company's plan); you read requirements for credentialing and submit paperwork
Step 2: after credentialing, the insurance company will send a contract which states, "we will pay you x% of Medicare reimbursement rates"
Step 3: you negotiate a higher rate based on x, y and z that you have to offer
For example, my partners and I command a larger than average reimbursement because we are the largest group in the state (so we can serve more of their members; this is very important to an insurance company: coverage), because we are fellowship trained (used to be the only ones in the area), have 4 offices so cover a wide range of hospitals and because we have data to show that fellowship trained surgeons in our specialty provide better care
Step 4: sign contract or refuse contractual offering
Step 5: insurance company tells you, "don't tell anyone we gave you this great rate"; of course, they tell everyone that so you think you are getting a special deal when you really aren't
Alternate Step 1-5: sometimes insurance companies will contact you, asking you to apply. These are almost always Medicaid type plans with poor reimbursement. You are not obligated to accept these; I take none which offer me less than Medicare reimbursement rates.
Sometimes negotiations can lead to some "interesting" conversations.
My partner (after we had added 2 other surgeons to our group): "So we get 130% of Medicare rates, and we'd like to add Drs. X and Y, as they are now under our Tax ID Number."
Insurance Company Rep: "Yes I see that Drs X and Y have been contracted with us at 90% of Medicare, so we will send a new contract to you for all of you to sign."
My partner: "Ok, so we will all get 130% of Medicare, right?"
ICR: "No, it will be for 90%."
My partner <WTF>: "No, we should all get 130% not 90%. We are providing more coverage for your members and as a larger group, we cover more hospitals giving your members better service."
ICR: "Yes, I understand, but we can't do 130%."
--- this goes on for some time
ICR: "It sounds as if we cannot come to an agreement, so we will just cancel the contract for all of the doctors."
My partner: <WTF>. "Please don't do that, I will call you back." <calls me>
Me: <trying not to laugh>: "So have you told Dr X (a "bigwig" in our specialty, former national society president) that you got his contract cancelled?"
--- long story short, we could not get them to agree to 130%, but we did get them to back off on dropping us from the panel and giving us 115%; loss for the 2 of us, gain for the other 2 surgeons.
Fun times.
These contracts are common for everything. Another example:
Office mgr <handing me a check to sign for biopsy needles>: "I need your signature here."
Me: "That's a lot of money. How many needles are we buying?"
Mgr <shows me bill>
Me: "That's like $47.50 a needle; I'm pretty sure we normally pay a lot less for them. Can you see what's going on?"
Mgr: "Sure"
She comes back a day later. We were being billed the non-contractual price for needles (yes, $47.50 each), as opposed to our contractually agreed upon price of about $15.00/needle. Apparently, our contract needed to be renewed and they sent an email to our former office mgr which of course, went unanswered and they never bothered to call or otherwise contact us, so just decided to charge us the "going rate".
I refused to pay that price and told her to send back the needles until they renewed our contract at the prior price, or we would just use the needle from their competitor.