When is the best time to change your company's health insurance?

The short answer: start on December 1

This page is for employers choosing a start date for a new company health plan. If you already know you want to switch and need the mechanics, see switching health insurance mid-year. For an employee changing their own coverage, see qualifying life events.

Three rules decide the best start date. Small group rates change at most once a quarter. Your rate is then fixed for your whole 12-month plan year. And most carriers count deductibles and out-of-pocket maximums on a calendar year, so they reset on January 1 no matter when your plan began.

Put those together and a December 1 start does two things. It buys a full year at the current year's fourth-quarter rate, while groups starting in January pay next year's higher rates. And it costs employees very little in deductible progress, because their old plan's deductible was about to reset on January 1 anyway.

Why plans start on the 1st

Almost every small group carrier starts coverage on the first day of a month. Premiums are billed by the month, eligibility files go to the carrier monthly, and payroll deductions line up most easily with a calendar month. If you miss a carrier's submission deadline for the 1st, the next option is usually the 1st of the following month.

How quarterly rates work, and why Q4 is the sweet spot

In the ACA small group market, a carrier may change its rates no more often than once a quarter. Federal rules allow new rates to take effect only on January 1, April 1, July 1 or October 1 (45 CFR 156.80(d)(4)(ii)). A new rate applies only to groups that start or renew on or after that date. Once your group's plan year begins, your rate holds for the entire plan year.

Carriers usually file their big annual increase for January 1. Through the rest of the year, quarterly changes tend to be smaller adjustments. So the rate a group locks in on December 1 belongs to the current year's filing. A group starting January 1 gets the new year's filing, and for 2027 those requests are large: KFF found that nearly 300 small group insurers proposed a median premium increase of 14% for 2027.

• A December 1 group pays the current fourth-quarter rate from December through November 30 of next year. Its first renewal is the following December 1, again ahead of the next January filing.
• A January 1 group pays the new year's first-quarter rate from day one.
• The gap repeats every year. Your renewal stays on a December cycle, so you keep landing on the older filing for 11 of every 12 months.

Two cautions. First, a fourth-quarter rate is not guaranteed to be lower: a carrier can file a larger October change, and a final January rate may be approved below the requested one. Compare the actual quotes for each start date. Second, the quarterly option does not apply in states that merged their individual and small group markets, such as Vermont and the District of Columbia, and some carriers choose to file only once a year.

When deductibles and out-of-pocket maximums reset

Your deductible and out-of-pocket maximum count spending over an accumulation period. For most small group carriers that period is the calendar year, so both reset on January 1 even if the policy renews in another month. Some plans use a plan year instead and reset on the renewal date. Check the Coverage Period line at the top of the summary of benefits and coverage (SBC) and confirm it in writing.

This is what makes December the cheapest month to switch. A new plan starts every employee's deductible at zero. In August that can throw away seven months of progress. On December 1 it throws away one month, because the old plan would have reset on January 1 regardless.

There is one wrinkle. If the new plan also uses a calendar year, it resets on January 1, a month after it started. December spending counts toward a deductible that lasts 31 days. For most employees that is a small amount. For someone with planned surgery or a hospital stay in December, it can be real money, so plan for it (see the exceptions below).

• Ask for a deductible credit. Some carriers credit amounts already paid under the prior plan when a group switches late in the year. Get the terms in writing, including the deadline and the documents required.
• Choose a plan where the reset matters less. With an effective $0 deductible and fixed copays, starting over costs employees very little.

Worked example: December 1 versus January 1

How to start a new plan on December 1

Carriers and administrators set their own submission deadlines, and they usually want applications and enrollment well before the start date. Treat the dates below as a planning guide and confirm the real ones.

1. Early November: check your exit terms Read your current policy or PEO contract for the cancellation notice period and the paid-through date. PEO contracts often need 30 to 90 days of notice. If you can't leave by November 30, pick the next first-of-month start that works.
2. Early November: get quotes for December 1 and January 1 Send the same census (dates of birth, ZIP codes, coverage tiers) and the same contribution policy to each option. Ask for both start dates so you see the real quarterly difference.
3. Mid-November: choose and apply Confirm the network covers your employees' doctors, check participation and contribution minimums, and submit the application by the carrier's deadline.
4. Mid-November: run enrollment Give each employee the SBC, collect elections and waivers, and update pre-tax payroll deductions. Tell anyone in treatment to ask about continuity of care.
5. After written approval: cancel the old plan Cancel effective November 30. Ask the old carrier for each member's deductible and out-of-pocket report for any credit request.
6. Late November: confirm ID cards and payroll Digital ID cards should be ready before December 1, and the first December paycheck should take the new deductions.

When December 1 is not the right date

• You can't meet participation or contribution minimums. Carriers may then sell you coverage only during an annual window from November 15 to December 15, for a January 1 start (45 CFR 147.104). December 1 isn't available.
• Someone has met their out-of-pocket maximum and has big care planned for December. A new plan restarts their count. Ask for a deductible credit, or move that one month's decision to January 1.
• Your current plan uses a plan-year deductible. If it resets on your renewal date rather than January 1, compare against that date instead.
• Your renewal is about to jump mid-year. If a large increase hits in April or July, switching then can beat waiting for December. Do the arithmetic: premium saving against lost deductible progress.
• Your contract won't let you out. Termination fees, run-out claims or a level-funded surplus you would forfeit can outweigh a quarter's rate difference.
• You are adding a first plan, not switching. Nobody has spending toward a deductible to lose, so any first-of-month date works. Start as soon as you are ready; Q4 is still a good quarter.

Common timing mistakes

• Waiting for January out of habit. January 1 is when most carriers' new annual increases take effect. A December 1 start avoids that increase for 11 months.
• Comparing quotes for different start dates. A December quote and a January quote use different filings. Compare like with like, then compare the two dates.
• Cancelling the old plan first. Cancel only after the new plan accepts you, effective the day before it starts.
• Forgetting payroll. Pre-tax deductions must change with the first paycheck the new plan covers.
• Not telling employees about the reset. Explain in the first message what happens to deductible progress and how to ask for a credit.

How Prescience makes the timing decision for you

Every rule above is something you shouldn't have to work out yourself. At Prescience we compare the rates for each possible start date, pick the date that locks in the best rate, line up the end of your old coverage so nobody has a gap, and optimize your plan for your team. You review one recommendation and approve it with one click.

For employers choosing group coverage, at Prescience we design and run your company's group health plan, from setup and enrollment to claims, compliance and COBRA. What your team gets:

• An effective $0 deductible, so the plan helps from the first visit.
• Simple copays shown before a visit, capped by a low out-of-pocket maximum.
• A broad national PPO network, plus providers we contract with directly.
• 24/7 physician-led care navigation: a care team that finds the right provider, books appointments and explains costs up front.

What your company gets: one monthly cost set in your quote, usually 10–20% below comparable fully insured coverage and fixed before the plan starts, with no admin fees. You keep your payroll provider, and the plan can start mid-year.