can your employer make you sign a new contract, or be fired for refusing.

the answer in 49 states is the at-will rule

In 49 U.S. states, employment is presumed to be at-will: the employee may quit at any time, and the employer may fire the employee for any reason and at any point, so long as the dismissal is not for an unlawful reason. The only exception is Montana, which generally requires good cause for dismissing an employee who has completed the probationary period. Wex, at-will employment — law.cornell.edu, read October 14, 2026.

That presumption answers the firing question before the contract is even read. An employer does not need the signature to lawfully end an at-will job; it needs the signature only to change the terms. The threat to end the job over the signature is therefore a threat to do something the employer could lawfully do anyway, which is exactly why it is usually not duress.

The same at-will doctrine runs in both directions, and the employer knows it. Nothing in the rule stops an employer from requiring an employment agreement as a condition of keeping the job — Cornell's own treatment notes employers may require employees to sign an agreement expressly stating the employment is at-will. Wex, at-will employment — law.cornell.edu, read October 14, 2026.

Montana is the 1 state where the question changes. Under the Wrongful Discharge from Employment Act, a discharge is wrongful if it was in retaliation, if it was not for good cause after the employee completed the employer's probationary period, or if the employer materially violated its own written personnel policy. Mont. Code Ann. § 39-2-904 — leg.mt.gov, read October 14, 2026.

refusing is not itself a protected refusal

"Refusing to sign" sounds like a protest, and protest at work is sometimes protected — but the protection attaches to how and with whom you refuse, not to the word no by itself.

The line the National Labor Relations Act draws is around concerted activity. Employees acting together about the terms of employment are protected; an employee who is singled out for an individual refusal is, in an at-will state, just an at-will employee. The Board's current standard for workplace rules takes the same shape in reverse: a rule that has a reasonable tendency to chill employees from exercising their Section 7 rights is presumptively unlawful. Stericycle Inc., 372 NLRB No. 113 — nlrb.gov, read October 14, 2026.

That case is about employer-drafted rules, which is the relevant point here. A new contract whose non-disparagement or confidentiality language could be read to forbid ordinary protected discussion is presumptively unlawful even if signed — the defect is in the text, not in the manner of signing.

The other unlawful reasons are the familiar ones outside labor law: firing the refusal of an employee because of their race, sex, age, disability or another protected trait, or because they filed a complaint, is unlawful whatever the paperwork says. At-will means any lawful reason, not any reason.

a modification binds only if something was given for it

A new contract mid-employment is a modification of the old one, and the ordinary rule is that a modification needs consideration to be binding. Where a party is already under a duty to perform, the performance of that existing duty is not consideration for the change, and a modification made without fresh consideration is voidable. Wex, pre-existing duty doctrine — law.cornell.edu, read October 14, 2026.

Applied to employment, the question is what the employer gave for the new terms. A raise, a bonus, extra vacation, a signing payment — that is fresh consideration, and the new terms bind. Nothing but the same job on worse terms is the case the doctrine exists for, and states differ on whether mere continued employment supplies it.

The practical consequence is that the weakest new contracts are the ones that only take. A document that adds obligations and subtracts nothing but the old terms is the 1 most vulnerable to the argument that nothing was given for it — though the argument runs after signing, not before it.

economic pressure is usually not duress

The hope people bring to this situation is that pressure defeats the signature. The doctrine is narrower than the hope. Duress makes a contract voidable where there was unlawful conduct or a threat of unlawful conduct that destroyed the party's free will, and the economic version requires improper or illegal conduct — not merely the fact that the alternative was worse. Wex, duress — law.cornell.edu, read October 14, 2026.

An employer threatening to do what it is lawfully entitled to do — end an at-will employment relationship if the terms are not accepted — is generally threatening a lawful act, which is the heart of why these signatures tend to hold.

The defense is not nothing. Where the pressure crosses into improper conduct — a threat that is itself unlawful, or conduct leaving no reasonable alternative — the contract is voidable. But it is voidable after the fact, in a dispute, on evidence, which is a worse position than never being pressured in the first place.

what even a signed new contract cannot take

The signature question ends; the content question does not. Terms the law voids stay voided by a signature.

Non-competes are the running example. California's statute makes every contract restraining anyone from engaging in a lawful profession, trade or business void to that extent, and the 2023 amendment removed the last doubt for employment: the application of any noncompete agreement in an employment context is void, no matter how narrowly tailored. Cal. Bus. & Prof. Code § 16600 — leginfo.legislature.ca.gov, read October 14, 2026.

The same pattern holds for the floors the law does not let parties bargain under: a pay rate below the statutory minimum cannot be waived by agreement, and a clause purporting to waive the right to file a charge with the EEOC or the NLRB waives nothing.

So the reading to do before signing a mid-employment change is not only what is being given and taken, but whether the new terms are of a kind the law will enforce at all.